Rilutek

Agents for Amyotrophic Lateral Sclerosis (ALS)

Administer at least 1 hour before or 2 hours after a meal.

Oral suspension
Gently shake the bottle for at least 30 seconds until mixed well.
Measure dosage using the provided calibrated syringe.
Storage: After opening the riluzole suspension bottle, use within 15 days.

Oral dissolving film
Do not cut or split the film.
Do not administer with liquids.
Administer only 1 film at a time.
Remove film from the foil pouch.
Apply the film to the top of the tongue where it adheres and dissolves.
As the film dissolves, swallow saliva in a normal manner. The patient should refrain from chewing, spitting, or talking.
Wash hands after handling.[64771]

Percutaneous Endoscopic Gastronomy (PEG) Tube Administration
Silicone and polyurethane PEG tubes can be used.
 
Oral suspension
Gently shake the bottle for at least 30 seconds until mixed well.
Measure dosage using the provided calibrated syringe.
Flush the PEG-tube with 30 mL of water using a catheter-tip syringe.
Administer the riluzole dose into the PEG tube immediately after flushing.
Flush the PEG-tube a second time with 30 mL of water.
Storage: After opening the riluzole suspension bottle, use within 15 days.

pancreatitis / Delayed / Incidence not known
anaphylactoid reactions / Rapid / Incidence not known

hypertension / Early / 5.0-5.0
sinus tachycardia / Rapid / 3.0-3.0
cystitis / Delayed / 3.0-3.0
peripheral edema / Delayed / 3.0-3.0
neutropenia / Delayed / 0-0.1
elevated hepatic enzymes / Delayed / Incidence not known
hepatitis / Delayed / Incidence not known
amnesia / Delayed / Incidence not known
interstitial lung disease / Delayed / Incidence not known
pneumonitis / Delayed / Incidence not known

headache / Early / 44.4-44.4
hypoesthesia / Delayed / 6.0-38.0
drowsiness / Early / 2.0-19.4
asthenia / Delayed / 19.0-19.0
dizziness / Early / 4.0-16.7
nausea / Early / 16.0-16.0
rhinitis / Early / 13.9-13.9
flatulence / Early / 3.0-8.3
abdominal pain / Early / 5.0-5.0
vomiting / Early / 4.0-4.0
xerostomia / Early / 4.0-4.0
insomnia / Early / 4.0-4.0
pruritus / Rapid / 4.0-4.0
arthralgia / Delayed / 4.0-4.0
anorexia / Delayed / 3.2-3.2
cough / Delayed / 3.0-3.0
diarrhea / Early / 2.9-2.9
vertigo / Early / 2.0-2.0
paresthesias / Delayed / 2.0-2.0

Exservan, Rilutek, Tiglutik

Rx

Oral glutamate antagonist
Used for treatment of amyotrophic lateral sclerosis (ALS)
Does not cure disease or improve symptoms, but may prolong survival by 3 months

50 mg PO twice daily.

100 mg PO twice daily. A randomized, placebo-controlled dose ranging trial evaluated the change in maximal chorea scores determined by the Unified Huntington's Disease Rating Scale (UHDRS) achieved at 8 weeks with riluzole 100 mg/day PO (n = 18), riluzole 200 mg/day PO (n = 23), or placebo (n = 22). Total daily dosages were divided and given twice daily. Subjects who received 200 mg/day had significant reductions in total chorea scores (-2.2 +/- 3.3, p = 0.01) compared to placebo (+0.7 +/- 3.4); effects appear to be dose related, as no significant reductions were found with riluzole 100 mg/day. In a second randomized controlled trial, patients were randomized to riluzole 50 mg twice daily or placebo for 3 years; no significant differences in UHDRS chorea scores between riluzole and placebo were found at 3 years.

†Indicates off-label use

Use is not recommended in patients with baseline elevation of serum transaminases more than 5 times the upper limit of normal (ULN) or evidence of liver dysfunction (e.g., elevated bilirubin).

Specific guidelines for dosage adjustments in renal impairment are not available; it appears that no dosage adjustments are needed. Riluzole has not been studied in patients undergoing hemodialysis.

Acetaminophen; Ibuprofen: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and ibuprofen. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Allopurinol: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and allopurinol. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Amiodarone: (Moderate) Coadministration of riluzole with amiodarone may increase the risk for riluzole-related adverse reactions, such as gastrointestinal symptoms and hepatotoxicity. Monitor for signs and symptoms of hepatic injury during coadministration. Discontinue riluzole if clinical signs of liver dysfunction are present. In vitro findings suggest an increase in riluzole exposure is likely; riluzole is a CYP1A2 substrate and amiodarone is a CYP1A2 inhibitor.
Amlodipine; Atorvastatin: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and atorvastatin. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Amoxicillin; Clarithromycin; Omeprazole: (Moderate) Coadministration of riluzole with omeprazole may result in decreased riluzole efficacy. In vitro findings suggest decreased riluzole exposure is likely. Riluzole is a CYP1A2 substrate and omeprazole is a CYP1A2 inducer.
Aspirin, ASA; Omeprazole: (Moderate) Coadministration of riluzole with omeprazole may result in decreased riluzole efficacy. In vitro findings suggest decreased riluzole exposure is likely. Riluzole is a CYP1A2 substrate and omeprazole is a CYP1A2 inducer.
Atorvastatin: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and atorvastatin. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Atorvastatin; Ezetimibe: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and atorvastatin. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Auranofin: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and auranofin. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Azathioprine: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and azathioprine. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Barbiturates: (Moderate) Coadministration of riluzole with barbiturates may result in decreased riluzole efficacy. In vitro findings suggest decreased riluzole exposure is likely. Riluzole is a CYP1A2 substrate and barbiturates are CYP1A2 inducers.
Busulfan: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and busulfan. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Capmatinib: (Moderate) Coadministration of riluzole with capmatinib may increase the risk for riluzole-related adverse reactions, such as gastrointestinal symptoms and elevated hepatic enzymes. In vitro findings suggest an increase in riluzole exposure is likely. Riluzole is a CYP1A2 substrate and capmatinib is a moderate CYP1A2 inhibitor.
Carbamazepine: (Moderate) Monitor for signs and symptoms of hepatic injury and decreased riluzole efficacy during coadministration of riluzole and carbamazepine. Concomitant use may increase the risk for hepatotoxicity and may result in decreased riluzole efficacy. In vitro findings suggest decreased riluzole exposure is likely. Riluzole is a CYP1A2 substrate and carbamazepine is a CYP1A2 inducer.
Chlorpheniramine; Ibuprofen; Pseudoephedrine: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and ibuprofen. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Chlorpromazine: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and chlorpromazine. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Ciprofloxacin: (Moderate) Coadministration of riluzole with ciprofloxacin may increase the risk for riluzole-related adverse reactions, such as gastrointestinal symptoms and elevated hepatic enzymes. In vitro findings suggest an increase in riluzole exposure is likely; riluzole is a CYP1A2 substrate and ciprofloxacin is a CYP1A2 inhibitor.
Dantrolene: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and dantrolene. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Deferasirox: (Moderate) Coadministration of riluzole with deferasirox may increase the risk for riluzole-related adverse reactions, such as gastrointestinal symptoms and elevated hepatic enzymes. In vitro findings suggest an increase in riluzole exposure is likely; riluzole is a CYP1A2 substrate and deferasirox is a CYP1A2 inhibitor.
Desogestrel; Ethinyl Estradiol: (Moderate) Monitor patients for increased riluzole-related adverse events, such as gastrointestinal symptoms and elevated hepatic enzymes, when hormonal contraceptives are prescribed concurrently. Serum concentrations of riluzole, a CYP1A2 substrate, may increase when oral contraceptives, moderate CYP1A2 inhibitors, are used concurrently. In vitro findings suggest an increase in riluzole exposure is likely when a CYP1A2 inhibitor is given.
Dextromethorphan; Quinidine: (Major) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and quinidine. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Diclofenac: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and diclofenac. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Diclofenac; Misoprostol: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and diclofenac. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Didanosine, ddI: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and didanosine. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Dienogest; Estradiol valerate: (Moderate) Monitor patients for increased riluzole-related adverse events, such as gastrointestinal symptoms and elevated hepatic enzymes, when hormonal contraceptives are prescribed concurrently. Serum concentrations of riluzole, a CYP1A2 substrate, may increase when oral contraceptives, moderate CYP1A2 inhibitors, are used concurrently. In vitro findings suggest an increase in riluzole exposure is likely when a CYP1A2 inhibitor is given.
Diphenhydramine; Ibuprofen: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and ibuprofen. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Disulfiram: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and disulfarim. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Drospirenone: (Moderate) Monitor patients for increased riluzole-related adverse events, such as gastrointestinal symptoms and elevated hepatic enzymes, when hormonal contraceptives are prescribed concurrently. Serum concentrations of riluzole, a CYP1A2 substrate, may increase when oral contraceptives, moderate CYP1A2 inhibitors, are used concurrently. In vitro findings suggest an increase in riluzole exposure is likely when a CYP1A2 inhibitor is given.
Drospirenone; Estetrol: (Moderate) Monitor patients for increased riluzole-related adverse events, such as gastrointestinal symptoms and elevated hepatic enzymes, when hormonal contraceptives are prescribed concurrently. Serum concentrations of riluzole, a CYP1A2 substrate, may increase when oral contraceptives, moderate CYP1A2 inhibitors, are used concurrently. In vitro findings suggest an increase in riluzole exposure is likely when a CYP1A2 inhibitor is given.
Drospirenone; Estradiol: (Moderate) Monitor patients for increased riluzole-related adverse events, such as gastrointestinal symptoms and elevated hepatic enzymes, when hormonal contraceptives are prescribed concurrently. Serum concentrations of riluzole, a CYP1A2 substrate, may increase when oral contraceptives, moderate CYP1A2 inhibitors, are used concurrently. In vitro findings suggest an increase in riluzole exposure is likely when a CYP1A2 inhibitor is given.
Drospirenone; Ethinyl Estradiol: (Moderate) Monitor patients for increased riluzole-related adverse events, such as gastrointestinal symptoms and elevated hepatic enzymes, when hormonal contraceptives are prescribed concurrently. Serum concentrations of riluzole, a CYP1A2 substrate, may increase when oral contraceptives, moderate CYP1A2 inhibitors, are used concurrently. In vitro findings suggest an increase in riluzole exposure is likely when a CYP1A2 inhibitor is given.
Drospirenone; Ethinyl Estradiol; Levomefolate: (Moderate) Monitor patients for increased riluzole-related adverse events, such as gastrointestinal symptoms and elevated hepatic enzymes, when hormonal contraceptives are prescribed concurrently. Serum concentrations of riluzole, a CYP1A2 substrate, may increase when oral contraceptives, moderate CYP1A2 inhibitors, are used concurrently. In vitro findings suggest an increase in riluzole exposure is likely when a CYP1A2 inhibitor is given.
Efavirenz: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and efavirenz. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Efavirenz; Emtricitabine; Tenofovir Disoproxil Fumarate: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and efavirenz. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Efavirenz; Lamivudine; Tenofovir Disoproxil Fumarate: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and efavirenz. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Elagolix; Estradiol; Norethindrone acetate: (Moderate) Monitor patients for increased riluzole-related adverse events, such as gastrointestinal symptoms and elevated hepatic enzymes, when hormonal contraceptives are prescribed concurrently. Serum concentrations of riluzole, a CYP1A2 substrate, may increase when oral contraceptives, moderate CYP1A2 inhibitors, are used concurrently. In vitro findings suggest an increase in riluzole exposure is likely when a CYP1A2 inhibitor is given.
Erythromycin: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and erythromycin. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Estradiol; Levonorgestrel: (Moderate) Monitor patients for increased riluzole-related adverse events, such as gastrointestinal symptoms and elevated hepatic enzymes, when hormonal contraceptives are prescribed concurrently. Serum concentrations of riluzole, a CYP1A2 substrate, may increase when oral contraceptives, moderate CYP1A2 inhibitors, are used concurrently. In vitro findings suggest an increase in riluzole exposure is likely when a CYP1A2 inhibitor is given.
Estradiol; Norethindrone: (Moderate) Monitor patients for increased riluzole-related adverse events, such as gastrointestinal symptoms and elevated hepatic enzymes, when hormonal contraceptives are prescribed concurrently. Serum concentrations of riluzole, a CYP1A2 substrate, may increase when oral contraceptives, moderate CYP1A2 inhibitors, are used concurrently. In vitro findings suggest an increase in riluzole exposure is likely when a CYP1A2 inhibitor is given.
Estradiol; Norgestimate: (Moderate) Monitor patients for increased riluzole-related adverse events, such as gastrointestinal symptoms and elevated hepatic enzymes, when hormonal contraceptives are prescribed concurrently. Serum concentrations of riluzole, a CYP1A2 substrate, may increase when oral contraceptives, moderate CYP1A2 inhibitors, are used concurrently. In vitro findings suggest an increase in riluzole exposure is likely when a CYP1A2 inhibitor is given.
Ethinyl Estradiol; Norelgestromin: (Moderate) Monitor patients for increased riluzole-related adverse events, such as gastrointestinal symptoms and elevated hepatic enzymes, when hormonal contraceptives are prescribed concurrently. Serum concentrations of riluzole, a CYP1A2 substrate, may increase when oral contraceptives, moderate CYP1A2 inhibitors, are used concurrently. In vitro findings suggest an increase in riluzole exposure is likely when a CYP1A2 inhibitor is given.
Ethinyl Estradiol; Norethindrone Acetate: (Moderate) Monitor patients for increased riluzole-related adverse events, such as gastrointestinal symptoms and elevated hepatic enzymes, when hormonal contraceptives are prescribed concurrently. Serum concentrations of riluzole, a CYP1A2 substrate, may increase when oral contraceptives, moderate CYP1A2 inhibitors, are used concurrently. In vitro findings suggest an increase in riluzole exposure is likely when a CYP1A2 inhibitor is given.
Ethinyl Estradiol; Norgestrel: (Moderate) Monitor patients for increased riluzole-related adverse events, such as gastrointestinal symptoms and elevated hepatic enzymes, when hormonal contraceptives are prescribed concurrently. Serum concentrations of riluzole, a CYP1A2 substrate, may increase when oral contraceptives, moderate CYP1A2 inhibitors, are used concurrently. In vitro findings suggest an increase in riluzole exposure is likely when a CYP1A2 inhibitor is given.
Ethynodiol Diacetate; Ethinyl Estradiol: (Moderate) Monitor patients for increased riluzole-related adverse events, such as gastrointestinal symptoms and elevated hepatic enzymes, when hormonal contraceptives are prescribed concurrently. Serum concentrations of riluzole, a CYP1A2 substrate, may increase when oral contraceptives, moderate CYP1A2 inhibitors, are used concurrently. In vitro findings suggest an increase in riluzole exposure is likely when a CYP1A2 inhibitor is given.
Etonogestrel; Ethinyl Estradiol: (Moderate) Monitor patients for increased riluzole-related adverse events, such as gastrointestinal symptoms and elevated hepatic enzymes, when hormonal contraceptives are prescribed concurrently. Serum concentrations of riluzole, a CYP1A2 substrate, may increase when oral contraceptives, moderate CYP1A2 inhibitors, are used concurrently. In vitro findings suggest an increase in riluzole exposure is likely when a CYP1A2 inhibitor is given.
Ezetimibe; Simvastatin: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and simvastatin. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Floxuridine: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and floxuridine. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Flutamide: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and flutamide. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Fluvoxamine: (Moderate) Coadministration of riluzole with fluvoxamine may increase the risk for riluzole-related adverse reactions, such as gastrointestinal symptoms and elevated hepatic enzymes. In vitro findings suggest an increase in riluzole exposure is likely; riluzole is a CYP1A2 substrate and fluvoxamine is a CYP1A2 inhibitor.
Food: (Major) Advise patients to avoid cannabis use during riluzole treatment due to decreased exposure of riluzole which may alter its efficacy. Cannabis use induces CYP1A2 and riluzole is a CYP1A2 substrate. The induction potential of cannabis is greatest with chronic inhalation. Other routes of administration or sporadic use may have less of an effect.
Fosphenytoin: (Moderate) Monitor for signs and symptoms of hepatic injury and decreased riluzole efficacy during coadministration of riluzole and fosphenytoin. Concomitant use may increase the risk for hepatotoxicity and may result in decreased riluzole efficacy. In vitro findings suggest decreased riluzole exposure is likely. Riluzole is a CYP1A2 substrate and fosphenytoin is a CYP1A2 inducer.
Green Tea: (Minor) Some green tea products contain caffeine, which may inhibit the CYP1A2-mediated metabolism of riluzole. Also, as a substrate for CYP1A2, riluzole might affect the clearance of other drugs that depend on CYP1A2 for hepatic oxidative metabolism, including caffeine. Clinical documentation is lacking.
Hydralazine: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and hydralazine. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Hydralazine; Isosorbide Dinitrate, ISDN: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and hydralazine. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Hydrochlorothiazide, HCTZ; Methyldopa: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and methyldopa. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Hydrocodone; Ibuprofen: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and ibuprofen. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Ibuprofen: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and ibuprofen. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Ibuprofen; Famotidine: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and ibuprofen. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Ibuprofen; Oxycodone: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and ibuprofen. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Ibuprofen; Pseudoephedrine: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and ibuprofen. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Infliximab: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and infliximab. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Interferon Alfa-2b: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and interferon alfa. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Interferon Alfa-n3: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and interferon alfa. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Interferon Beta-1a: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and interferon beta. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Interferon Beta-1b: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and interferon beta. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Isoniazid, INH: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and isoniazid. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Isoniazid, INH; Pyrazinamide, PZA; Rifampin: (Moderate) Monitor for signs and symptoms of hepatic injury and decreased riluzole efficacy during coadministration of riluzole and rifampin. Concomitant use may increase the risk for hepatotoxicity and may result in decreased riluzole efficacy. In vitro findings suggest decreased riluzole exposure is likely. Riluzole is a CYP1A2 substrate and rifampin is a CYP1A2 inducer. (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and isoniazid. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present. (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and pyrazinamide. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Isoniazid, INH; Rifampin: (Moderate) Monitor for signs and symptoms of hepatic injury and decreased riluzole efficacy during coadministration of riluzole and rifampin. Concomitant use may increase the risk for hepatotoxicity and may result in decreased riluzole efficacy. In vitro findings suggest decreased riluzole exposure is likely. Riluzole is a CYP1A2 substrate and rifampin is a CYP1A2 inducer. (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and isoniazid. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Ketoconazole: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and ketoconazole. Concomitant use may increase the risk for hepatotoxicity. Discontinue therapy if clinical signs of liver dysfunction are present.
Leflunomide: (Moderate) Coadministration of riluzole with leflunomide may result in decreased riluzole efficacy. In vitro findings suggest decreased riluzole exposure is likely. Riluzole is a CYP1A2 substrate and leflunomide is a CYP1A2 inducer.
Lesinurad; Allopurinol: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and allopurinol. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Leuprolide; Norethindrone: (Moderate) Monitor patients for increased riluzole-related adverse events, such as gastrointestinal symptoms and elevated hepatic enzymes, when hormonal contraceptives are prescribed concurrently. Serum concentrations of riluzole, a CYP1A2 substrate, may increase when oral contraceptives, moderate CYP1A2 inhibitors, are used concurrently. In vitro findings suggest an increase in riluzole exposure is likely when a CYP1A2 inhibitor is given.
Levoketoconazole: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and ketoconazole. Concomitant use may increase the risk for hepatotoxicity. Discontinue therapy if clinical signs of liver dysfunction are present.
Levonorgestrel: (Moderate) Monitor patients for increased riluzole-related adverse events, such as gastrointestinal symptoms and elevated hepatic enzymes, when hormonal contraceptives are prescribed concurrently. Serum concentrations of riluzole, a CYP1A2 substrate, may increase when oral contraceptives, moderate CYP1A2 inhibitors, are used concurrently. In vitro findings suggest an increase in riluzole exposure is likely when a CYP1A2 inhibitor is given.
Levonorgestrel; Ethinyl Estradiol: (Moderate) Monitor patients for increased riluzole-related adverse events, such as gastrointestinal symptoms and elevated hepatic enzymes, when hormonal contraceptives are prescribed concurrently. Serum concentrations of riluzole, a CYP1A2 substrate, may increase when oral contraceptives, moderate CYP1A2 inhibitors, are used concurrently. In vitro findings suggest an increase in riluzole exposure is likely when a CYP1A2 inhibitor is given.
Levonorgestrel; Ethinyl Estradiol; Ferrous Bisglycinate: (Moderate) Monitor patients for increased riluzole-related adverse events, such as gastrointestinal symptoms and elevated hepatic enzymes, when hormonal contraceptives are prescribed concurrently. Serum concentrations of riluzole, a CYP1A2 substrate, may increase when oral contraceptives, moderate CYP1A2 inhibitors, are used concurrently. In vitro findings suggest an increase in riluzole exposure is likely when a CYP1A2 inhibitor is given.
Levonorgestrel; Ethinyl Estradiol; Ferrous Fumarate: (Moderate) Monitor patients for increased riluzole-related adverse events, such as gastrointestinal symptoms and elevated hepatic enzymes, when hormonal contraceptives are prescribed concurrently. Serum concentrations of riluzole, a CYP1A2 substrate, may increase when oral contraceptives, moderate CYP1A2 inhibitors, are used concurrently. In vitro findings suggest an increase in riluzole exposure is likely when a CYP1A2 inhibitor is given.
Lopinavir; Ritonavir: (Moderate) Coadministration of riluzole with ritonavir may result in decreased riluzole efficacy. In vitro findings suggest decreased riluzole exposure is likely. Riluzole is a CYP1A2 substrate and ritonavir is a CYP1A2 inducer.
Mercaptopurine, 6-MP: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and mercaptopurine. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Methotrexate: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and methotrexate. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Methoxsalen: (Moderate) Coadministration of riluzole with methoxsalen may increase the risk for riluzole-related adverse reactions, such as gastrointestinal symptoms and elevated hepatic enzymes. In vitro findings suggest an increase in riluzole exposure is likely; riluzole is a CYP1A2 substrate and methoxsalen is a CYP1A2 inhibitor.
Methyldopa: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and methyldopa. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Mexiletine: (Moderate) Coadministration of riluzole with mexiletine may increase the risk for riluzole-related adverse reactions, such as gastrointestinal symptoms and elevated hepatic enzymes. In vitro findings suggest an increase in riluzole exposure is likely; riluzole is a CYP1A2 substrate and mexiletine is a CYP1A2 inhibitor.
Minocycline: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and minocycline. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Modafinil: (Moderate) Coadministration of riluzole with modafinil may result in decreased riluzole efficacy. In vitro findings suggest decreased riluzole exposure is likely. Riluzole is a CYP1A2 substrate and modafinil is a CYP1A2 inducer.
Nevirapine: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and nevirapine. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Niacin; Simvastatin: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and simvastatin. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Nirmatrelvir; Ritonavir: (Moderate) Coadministration of riluzole with ritonavir may result in decreased riluzole efficacy. In vitro findings suggest decreased riluzole exposure is likely. Riluzole is a CYP1A2 substrate and ritonavir is a CYP1A2 inducer.
Nitrofurantoin: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and nitrofurantoin. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Norethindrone Acetate; Ethinyl Estradiol; Ferrous fumarate: (Moderate) Monitor patients for increased riluzole-related adverse events, such as gastrointestinal symptoms and elevated hepatic enzymes, when hormonal contraceptives are prescribed concurrently. Serum concentrations of riluzole, a CYP1A2 substrate, may increase when oral contraceptives, moderate CYP1A2 inhibitors, are used concurrently. In vitro findings suggest an increase in riluzole exposure is likely when a CYP1A2 inhibitor is given.
Norethindrone: (Moderate) Monitor patients for increased riluzole-related adverse events, such as gastrointestinal symptoms and elevated hepatic enzymes, when hormonal contraceptives are prescribed concurrently. Serum concentrations of riluzole, a CYP1A2 substrate, may increase when oral contraceptives, moderate CYP1A2 inhibitors, are used concurrently. In vitro findings suggest an increase in riluzole exposure is likely when a CYP1A2 inhibitor is given.
Norethindrone; Ethinyl Estradiol: (Moderate) Monitor patients for increased riluzole-related adverse events, such as gastrointestinal symptoms and elevated hepatic enzymes, when hormonal contraceptives are prescribed concurrently. Serum concentrations of riluzole, a CYP1A2 substrate, may increase when oral contraceptives, moderate CYP1A2 inhibitors, are used concurrently. In vitro findings suggest an increase in riluzole exposure is likely when a CYP1A2 inhibitor is given.
Norethindrone; Ethinyl Estradiol; Ferrous fumarate: (Moderate) Monitor patients for increased riluzole-related adverse events, such as gastrointestinal symptoms and elevated hepatic enzymes, when hormonal contraceptives are prescribed concurrently. Serum concentrations of riluzole, a CYP1A2 substrate, may increase when oral contraceptives, moderate CYP1A2 inhibitors, are used concurrently. In vitro findings suggest an increase in riluzole exposure is likely when a CYP1A2 inhibitor is given.
Norgestimate; Ethinyl Estradiol: (Moderate) Monitor patients for increased riluzole-related adverse events, such as gastrointestinal symptoms and elevated hepatic enzymes, when hormonal contraceptives are prescribed concurrently. Serum concentrations of riluzole, a CYP1A2 substrate, may increase when oral contraceptives, moderate CYP1A2 inhibitors, are used concurrently. In vitro findings suggest an increase in riluzole exposure is likely when a CYP1A2 inhibitor is given.
Norgestrel: (Moderate) Monitor patients for increased riluzole-related adverse events, such as gastrointestinal symptoms and elevated hepatic enzymes, when hormonal contraceptives are prescribed concurrently. Serum concentrations of riluzole, a CYP1A2 substrate, may increase when oral contraceptives, moderate CYP1A2 inhibitors, are used concurrently. In vitro findings suggest an increase in riluzole exposure is likely when a CYP1A2 inhibitor is given.
Omeprazole: (Moderate) Coadministration of riluzole with omeprazole may result in decreased riluzole efficacy. In vitro findings suggest decreased riluzole exposure is likely. Riluzole is a CYP1A2 substrate and omeprazole is a CYP1A2 inducer.
Omeprazole; Amoxicillin; Rifabutin: (Moderate) Coadministration of riluzole with omeprazole may result in decreased riluzole efficacy. In vitro findings suggest decreased riluzole exposure is likely. Riluzole is a CYP1A2 substrate and omeprazole is a CYP1A2 inducer.
Omeprazole; Sodium Bicarbonate: (Moderate) Coadministration of riluzole with omeprazole may result in decreased riluzole efficacy. In vitro findings suggest decreased riluzole exposure is likely. Riluzole is a CYP1A2 substrate and omeprazole is a CYP1A2 inducer.
Oral Contraceptives: (Moderate) Monitor patients for increased riluzole-related adverse events, such as gastrointestinal symptoms and elevated hepatic enzymes, when hormonal contraceptives are prescribed concurrently. Serum concentrations of riluzole, a CYP1A2 substrate, may increase when oral contraceptives, moderate CYP1A2 inhibitors, are used concurrently. In vitro findings suggest an increase in riluzole exposure is likely when a CYP1A2 inhibitor is given.
Peginterferon Alfa-2a: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and peginterferon alfa-2a. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Peginterferon Alfa-2b: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and peginterferon alfa-2b. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Peginterferon beta-1a: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and peginterferon beta-1a. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Pexidartinib: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and pexidartinib. Discontinue riluzole if clinical signs of liver dysfunction are present. Concomitant use may increase the risk for hepatotoxicity.
Phenytoin: (Moderate) Monitor for signs and symptoms of hepatic injury and decreased riluzole efficacy during coadministration of riluzole and phenytoin. Concomitant use may increase the risk for hepatotoxicity and may result in decreased riluzole efficacy. In vitro findings suggest decreased riluzole exposure is likely. Riluzole is a CYP1A2 substrate and phenytoin is a CYP1A2 inducer.
Pretomanid: (Major) Avoid coadministration of pretomanid with riluzole, especially in patients with impaired hepatic function, due to increased risk for hepatotoxicity. Monitor for evidence of hepatotoxicity if coadministration is necessary. If new or worsening hepatic dysfunction occurs, discontinue hepatotoxic medications.
Propylthiouracil, PTU: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and propylthiouracil. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Pyrazinamide, PZA: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and pyrazinamide. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Quinidine: (Major) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and quinidine. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Quinine: (Moderate) Coadministration of riluzole with quinine may result in decreased riluzole efficacy. In vitro findings suggest decreased riluzole exposure is likely. Riluzole is a CYP1A2 substrate and quinine is a CYP1A2 inducer.
Relugolix; Estradiol; Norethindrone acetate: (Moderate) Monitor patients for increased riluzole-related adverse events, such as gastrointestinal symptoms and elevated hepatic enzymes, when hormonal contraceptives are prescribed concurrently. Serum concentrations of riluzole, a CYP1A2 substrate, may increase when oral contraceptives, moderate CYP1A2 inhibitors, are used concurrently. In vitro findings suggest an increase in riluzole exposure is likely when a CYP1A2 inhibitor is given.
Rifampin: (Moderate) Monitor for signs and symptoms of hepatic injury and decreased riluzole efficacy during coadministration of riluzole and rifampin. Concomitant use may increase the risk for hepatotoxicity and may result in decreased riluzole efficacy. In vitro findings suggest decreased riluzole exposure is likely. Riluzole is a CYP1A2 substrate and rifampin is a CYP1A2 inducer.
Ritlecitinib: (Moderate) Coadministration of riluzole with ritlecitinib may increase the risk for riluzole-related adverse reactions, such as gastrointestinal symptoms and elevated hepatic enzymes. In vitro findings suggest an increase in riluzole exposure is likely. Riluzole is a CYP1A2 substrate and ritlecitinib is a moderate CYP1A2 inhibitor.
Ritonavir: (Moderate) Coadministration of riluzole with ritonavir may result in decreased riluzole efficacy. In vitro findings suggest decreased riluzole exposure is likely. Riluzole is a CYP1A2 substrate and ritonavir is a CYP1A2 inducer.
Rucaparib: (Moderate) Coadministration of riluzole with rucaparib may increase the risk for riluzole-related adverse reactions, such as gastrointestinal symptoms and elevated hepatic enzymes. In vitro findings suggest an increase in riluzole exposure is likely; riluzole is a CYP1A2 substrate and rucaparib is a CYP1A2 inhibitor.
Segesterone Acetate; Ethinyl Estradiol: (Moderate) Monitor patients for increased riluzole-related adverse events, such as gastrointestinal symptoms and elevated hepatic enzymes, when hormonal contraceptives are prescribed concurrently. Serum concentrations of riluzole, a CYP1A2 substrate, may increase when oral contraceptives, moderate CYP1A2 inhibitors, are used concurrently. In vitro findings suggest an increase in riluzole exposure is likely when a CYP1A2 inhibitor is given.
Simvastatin: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and simvastatin. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Sodium Phenylbutyrate; Taurursodiol: (Moderate) Coadministration of riluzole with taurursodiol may result in decreased riluzole efficacy. In vitro findings suggest decreased riluzole exposure is likely. Riluzole is a CYP1A2 substrate and taurursodiol is a CYP1A2 inducer.
St. John's Wort, Hypericum perforatum: (Moderate) Coadministration of riluzole with St. John's Wort may result in decreased riluzole efficacy. In vitro findings suggest decreased riluzole exposure is likely. Riluzole is a CYP1A2 substrate and St. John's Wort is a CYP1A2 inducer.
Sulfadiazine: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and sulfadiazine. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Sulfamethoxazole; Trimethoprim, SMX-TMP, Cotrimoxazole: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and sulfamethoxazole. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Sulfasalazine: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and sulfasalazine. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Sulindac: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and sulindac. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Teriflunomide: (Moderate) Coadministration of riluzole with teriflunomide may result in decreased riluzole efficacy. In vitro findings suggest decreased riluzole exposure is likely. Riluzole is a CYP1A2 substrate and teriflunomide is a CYP1A2 inducer.
Testosterone: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and testosterone. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Thioguanine, 6-TG: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and thioguanine. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Ticlopidine: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and ticlopidine. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Tipranavir: (Moderate) Coadministration of riluzole with tipranavir may result in decreased riluzole efficacy. In vitro findings suggest decreased riluzole exposure is likely. Riluzole is a CYP1A2 substrate and tipranavir is a CYP1A2 inducer.
Tobacco: (Major) Advise patients to avoid smoking tobacco while taking riluzole. Smoking tobacco has been observed to enhance riluzole clearance by greater than 20% which may decrease riluzole exposure and result in loss of efficacy. Riluzole is a CYP1A2 substrate and smoking tobacco induces CYP1A2.
Valproic Acid, Divalproex Sodium: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and valproic acid. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Vemurafenib: (Moderate) Coadministration of riluzole with vemurafenib may increase the risk for riluzole-related adverse reactions, such as gastrointestinal symptoms and elevated hepatic enzymes. In vitro findings suggest an increase in riluzole exposure is likely; riluzole is a CYP1A2 substrate and vemurafenib is a CYP1A2 inhibitor.
Viloxazine: (Moderate) Coadministration of riluzole with viloxazine may increase the risk for riluzole-related adverse reactions, such as gastrointestinal symptoms and elevated hepatic enzymes. In vitro findings suggest an increase in riluzole exposure is likely. Riluzole is a CYP1A2 substrate and viloxazine is a strong CYP1A2 inhibitor.
Zafirlukast: (Moderate) Coadministration of riluzole with zafirlukast may increase the risk for riluzole-related adverse reactions, such as gastrointestinal symptoms and elevated hepatic enzymes. In vitro findings suggest an increase in riluzole exposure is likely; riluzole is a CYP1A2 substrate and zafirlukast is a CYP1A2 inhibitor.

Exservan Oral Film: 50mg
Rilutek/Riluzole Oral Tab: 50mg
Tiglutik Oral Susp: 1mL, 5mg

100 mg/day PO for ALS; 200 mg/day PO off-label for Huntington's Chorea.

100mg/day PO for ALS; 200 mg/day PO off-label for Huntington's Chorea.

Safety and efficacy have not been established.

Safety and efficacy have not been established.

Safety and efficacy have not been established.

Safety and efficacy have not been established.

Riluzole modulates the actions of glutamate. The mechanism by which this happens is not clearly known but may include direct effects on the neurotransmitter itself and target receptors, the inhibition of glutamate release, blockade or inactivation of voltage-dependent sodium channels that are important for glutamate release, interference with intracellular events that result from binding of glutamate to receptors, and/or inhibition of arachidonic acid metabolism. Animal studies have shown that riluzole has a neuroprotective effect that delays neuronal injury or death.

Riluzole is administered orally. Riluzole is highly bound to plasma protein (about 96%), mainly to albumin and lipoproteins. Hepatic metabolism is extensive, producing 6 major and a number of minor metabolites. The primary metabolic pathways are oxidation by CYP1A2 and direct and sequential glucoronidation by UGT-HP4. Approximately 90% of a dose is excreted in the urine; however, only 2% is excreted as unchanged drug. Elimination in the feces accounts for 5% of a dose. Riluzole is largely excreted as its glucuronide metabolites (85%). The elimination half-life is 12 hours.
 
Affected cytochrome P450 isoenzymes and drug transporters: CYP1A2, UGT-HP4
Riluzole is primarily metabolized by CYP1A2 and UGT-HP4.

Riluzole is well absorbed from the GI tract (90%) and has absolute bioavailability of about 60%. Absorption is affected by high-fat meals, which reduce the AUC by about 20% and peak blood concentrations by about 45%. Riluzole exhibits linear pharmacokinetics. Steady-state plasma concentrations are achieved within 5 days of multiple-dose administration. Riluzole has similar pharmacokinetic properties after intragastric administration via feeding tubes and oral administration.

There are no adequate human data to inform the drug-associated risk with riluzole use during pregnancy. Increased mortality and other adverse developmental effects were observed during reproductive animal studies with riluzole at clinically relevant doses. When riluzole was given orally (3, 10, or 60 mg/kg/day) to pregnant rabbits during organogenesis, embryofetal mortality was increased at the high dose, and decreased fetal body weight and increased morphological variations were observed at all but the lowest dose. The no-effect dose (3 mg/kg/day) for embryofetal developmental toxicity is less than the recommended human daily dose (RHDD, 100 mg) on mg/m2 basis. Administration of oral riluzole (3, 8, or 15 mg/kg/day) to male and female rats prior to and during mating and to female rats throughout gestation and lactation increased embryofetal mortality and decreased postnatal offspring viability, growth, and functional development at the high dose; the no-effect dose (8 mg/kg/day) for embryofetal developmental toxicity was approximately equal to the RHDD on mg/m2 basis. Fertility indices were decreased at the high dose.

Riluzole is excreted in human milk. The average riluzole breast milk concentration was 94.4 mcg/L during a regimen of 50 mg twice daily in a breast-feeding woman with amyotrophic lateral sclerosis (ALS). A study predose breast milk sample was 33.8 ng/mL, suggesting steady-state riluzole concentrations; the peak riluzole concentration was 229.5 ng/mL at 2 hours after the dose. The calculated infant dose was 14.1 mcg/kg/day, and the calculated relative infant dose was 1.6% of the maternal weight-adjusted dosage with an average milk intake of 150 mL/kg/day.[63535] There are no data on the effects of riluzole on the breast-fed infant or on milk production. Consider the developmental and health benefits of breast-feeding along with the mother's clinical need for riluzole and any potential adverse effects on the breast-fed infant from riluzole or the underlying maternal condition.[64771]