Ziana

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Ziana

Classes

Topical Anti-Infective and Retinoid Combinations for Acne

Administration

Hazardous Drugs Classification
Tretinoin is classified as a hazardous drug.
NIOSH 2016 List: Group 3
NIOSH (Draft) 2020 List: Table 2
Observe and exercise appropriate precautions for handling, preparation, administration, and disposal of hazardous drugs.
Use double chemotherapy gloves and protective gown. Eye/face and respiratory protection may be needed during preparation and administration. ]

Topical Administration

Apply topically to the skin. Do not use orally, ophthalmically, or intravaginally.
Prior to administration, gently wash the skin of the affected areas, rinse with warm water, and pat dry.
Squeeze a pea-sized amount of the product onto one fingertip, dot onto the chin, cheeks, nose, and forehead, then gently rub over the entire face.
Keep the product away from the eyes, mucous membranes, and angles of the nose.

Adverse Reactions
Severe

C. difficile-associated diarrhea / Delayed / Incidence not known

Moderate

erythema / Early / 4.0-35.0
pseudomembranous colitis / Delayed / Incidence not known
colitis / Delayed / Incidence not known
superinfection / Delayed / Incidence not known

Mild

xerosis / Delayed / 1.0-22.0
pruritus / Rapid / 2.0-15.0
skin irritation / Early / 5.0-5.0
pharyngitis / Delayed / 0-4.0
cough / Delayed / 1.0-1.0
sinusitis / Delayed / 1.0-1.0
photosensitivity / Delayed / Incidence not known
skin hypopigmentation / Delayed / Incidence not known
skin hyperpigmentation / Delayed / Incidence not known
diarrhea / Early / Incidence not known

Common Brand Names

Veltin, Ziana

Dea Class

Rx

Description

Combination acne therapy in an alcohol-free hydrogel for topical use; clindamycin is an antibacterial agent and tretinoin (all-trans-retinoic acid or ATRA) is a retinoid and derivative of vitamin A (retinol); tretinoin normalizes desquamation of the follicular epithelium and reduces the number of comedones and inflammatory lesions.

Dosage And Indications
For the treatment of acne vulgaris caused by Propionibacterium acnes. Topical dosage (Ziana) Adults, Adolescents, and Children 12 years and older

Apply to affected areas once daily at bedtime.

Topical dosage (Veltin) Adults, Adolescents, and Children 12 years and older

Apply to the affected area once daily in the evening.

Dosing Considerations
Hepatic Impairment

Data are not available for this population; no quantitative recommendations are available.

Renal Impairment

Data are not available for this population; no quantitative recommendations are available.

Drug Interactions

Adapalene; Benzoyl Peroxide: (Moderate) Benzoyl peroxide can potentiate the skin irritation caused by topical tretinoin. Concurrent application of these agents on areas treated with tretinoin should be avoided.
Aliskiren; Hydrochlorothiazide, HCTZ: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as thiazide diuretics, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Amiloride; Hydrochlorothiazide, HCTZ: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as thiazide diuretics, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Amlodipine; Valsartan; Hydrochlorothiazide, HCTZ: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as thiazide diuretics, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Atenolol; Chlorthalidone: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as thiazide diuretics, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Azilsartan; Chlorthalidone: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as thiazide diuretics, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Benazepril; Hydrochlorothiazide, HCTZ: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as thiazide diuretics, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Benzoyl Peroxide: (Moderate) Benzoyl peroxide can potentiate the skin irritation caused by topical tretinoin. Concurrent application of these agents on areas treated with tretinoin should be avoided.
Benzoyl Peroxide; Clindamycin: (Moderate) Benzoyl peroxide can potentiate the skin irritation caused by topical tretinoin. Concurrent application of these agents on areas treated with tretinoin should be avoided.
Benzoyl Peroxide; Erythromycin: (Moderate) Benzoyl peroxide can potentiate the skin irritation caused by topical tretinoin. Concurrent application of these agents on areas treated with tretinoin should be avoided.
Benzoyl Peroxide; Sulfur: (Moderate) Benzoyl peroxide can potentiate the skin irritation caused by topical tretinoin. Concurrent application of these agents on areas treated with tretinoin should be avoided.
Bisoprolol; Hydrochlorothiazide, HCTZ: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as thiazide diuretics, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Candesartan; Hydrochlorothiazide, HCTZ: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as thiazide diuretics, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Captopril; Hydrochlorothiazide, HCTZ: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as thiazide diuretics, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Chlorothiazide: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as thiazide diuretics, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Chlorpromazine: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as phenothiazines, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Chlorpropamide: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as sulfonylureas, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Chlorthalidone: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as thiazide diuretics, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Chlorthalidone; Clonidine: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as thiazide diuretics, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Ciprofloxacin: (Major) Avoid the concomitant use of tretinoin with other drugs known to cause photosensitivity, such as ciprofloxacin. Concomitant use with other photosensitizing agents may increase the risk of a photosensitivity reaction.
Codeine; Phenylephrine; Promethazine: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as phenothiazines, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Codeine; Promethazine: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as phenothiazines, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Enalapril; Hydrochlorothiazide, HCTZ: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as thiazide diuretics, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Eprosartan; Hydrochlorothiazide, HCTZ: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as thiazide diuretics, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Fluphenazine: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as phenothiazines, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Fosinopril; Hydrochlorothiazide, HCTZ: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as thiazide diuretics, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Gemifloxacin: (Major) Avoid the concomitant use of tretinoin with other drugs known to cause photosensitivity, such as gemifloxacin. Concomitant use with other photosensitizing agents may increase the risk of a photosensitivity reaction.
Glimepiride: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as sulfonylureas, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Glipizide: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as sulfonylureas, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Glipizide; Metformin: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as sulfonylureas, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Glyburide: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as sulfonylureas, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Glyburide; Metformin: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as sulfonylureas, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Hydrochlorothiazide, HCTZ: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as thiazide diuretics, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Hydrochlorothiazide, HCTZ; Methyldopa: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as thiazide diuretics, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Hydrochlorothiazide, HCTZ; Moexipril: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as thiazide diuretics, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Irbesartan; Hydrochlorothiazide, HCTZ: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as thiazide diuretics, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Levofloxacin: (Major) Avoid the concomitant use of tretinoin with other drugs known to cause photosensitivity, such as levofloxacin. Concomitant use with other photosensitizing agents may increase the risk of a photosensitivity reaction.
Lisinopril; Hydrochlorothiazide, HCTZ: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as thiazide diuretics, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Losartan; Hydrochlorothiazide, HCTZ: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as thiazide diuretics, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Methyclothiazide: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as thiazide diuretics, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Metolazone: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as thiazide diuretics, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Metoprolol; Hydrochlorothiazide, HCTZ: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as thiazide diuretics, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Moxifloxacin: (Major) Avoid the concomitant use of tretinoin with other drugs known to cause photosensitivity, such as moxifloxacin. Concomitant use with other photosensitizing agents may increase the risk of a photosensitivity reaction.
Ofloxacin: (Major) Avoid the concomitant use of tretinoin with other drugs known to cause photosensitivity, such as ofloxacin. Concomitant use with other photosensitizing agents may increase the risk of a photosensitivity reaction.
Olmesartan; Amlodipine; Hydrochlorothiazide, HCTZ: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as thiazide diuretics, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Olmesartan; Hydrochlorothiazide, HCTZ: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as thiazide diuretics, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Perphenazine: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as phenothiazines, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Perphenazine; Amitriptyline: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as phenothiazines, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Phenothiazines: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as phenothiazines, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Pioglitazone; Glimepiride: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as sulfonylureas, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Prochlorperazine: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as phenothiazines, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Promethazine: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as phenothiazines, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Promethazine; Dextromethorphan: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as phenothiazines, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Promethazine; Phenylephrine: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as phenothiazines, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Propranolol; Hydrochlorothiazide, HCTZ: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as thiazide diuretics, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Quinapril; Hydrochlorothiazide, HCTZ: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as thiazide diuretics, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Salicylic Acid: (Moderate) When concomitantly prescribed for acne therapy, apply salicylic acid and clindamycin topical solutions separately, at different times of the day to minimize skin irritation, unless directed otherwise by the prescriber. If skin irritation occurs, a decrease in dose or frequency of one or both agents may be necessary.
Sodium Thiosulfate; Salicylic Acid: (Moderate) When concomitantly prescribed for acne therapy, apply salicylic acid and clindamycin topical solutions separately, at different times of the day to minimize skin irritation, unless directed otherwise by the prescriber. If skin irritation occurs, a decrease in dose or frequency of one or both agents may be necessary.
Spironolactone; Hydrochlorothiazide, HCTZ: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as thiazide diuretics, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Sulfonylureas: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as sulfonylureas, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Telmisartan; Hydrochlorothiazide, HCTZ: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as thiazide diuretics, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Thiazide diuretics: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as thiazide diuretics, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Thioridazine: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as phenothiazines, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Tolazamide: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as sulfonylureas, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Tolbutamide: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as sulfonylureas, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Tretinoin; Benzoyl Peroxide: (Moderate) Benzoyl peroxide can potentiate the skin irritation caused by topical tretinoin. Concurrent application of these agents on areas treated with tretinoin should be avoided.
Triamterene; Hydrochlorothiazide, HCTZ: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as thiazide diuretics, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Trifluoperazine: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as phenothiazines, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.
Valsartan; Hydrochlorothiazide, HCTZ: (Moderate) A manufacturer of topical tretinoin states that tretinoin, ATRA should be administered with caution in patients who are also taking drugs known to be photosensitizers, such as thiazide diuretics, as concomitant use may augment phototoxicity. Patients should take care and use proper techniques to limit sunlight and UV exposure of treated areas.

How Supplied

Clindamycin Phosphate, Tretinoin/Clindamycin, Tretinoin/Veltin/Ziana Topical Gel: 1.2-0.025%

Maximum Dosage
Adults

Maximum dosage information not available.

Elderly

Maximum dosage information not available.

Adolescents

Maximum dosage information not available.

Children

>= 12 years: Maximum dosage information not available.
< 12 years: Not recommended.

Infants

Not recommended.

Mechanism Of Action

•Clindamycin: Clindamycin antibacterial activity results from inhibition of protein synthesis. The antibiotic binds to the 50 S ribosomal subunits of bacteria, thereby inhibiting protein synthesis. Clindamycin is either bacteriostatic or bactericidal, depending on its concentration at the site of action and on the specific susceptibility of the organism being treated. Clindamycin is active against Propionibacterium acnes, which is part of the normal flora of the skin and is believed to be a primary cause of acne. Propionibacterium acnes metabolizes sebaceous triglycerides, consumes glycerol, and produces free fatty acids. Propionibacterium acnes and the production of fatty acids are believed to stimulate neutrophil chemoattractants, activate compliment, and result in an inflammatory response. Inhibition of P. acnes reduces the concentration of free fatty acids in sebum, which may be the cause of inflammatory lesions associated with acne. Propionibacterium acnes has developed resistance to topical clindamycin, therefore it is recommended to change medication therapy if the patient fails to respond in 4—8 weeks.
 
•Tretinoin: In treating skin disorders, tretinoin binds to retinoic acid receptors (RARs) which then modifies gene expression, subsequent protein synthesis, and epithelial cell growth and differentiation. It has not been established whether the clinical effects of tretinoin are mediated through activation of RARs, other mechanisms such as irritation, or both. Tretinoin appears to prevent horny cell cohesion and to increase epidermal cell turnover and mitotic activity. Subsequently, in patients with acne, expulsion of existing comedones occurs, and formation of new comedones is prevented through sloughing and expulsion of horny cells from the follicle. Tretinoin reduces the cell layers of the stratum corneum. The bacterium involved in acne, Propionibacterium acnes, and sebum production are unaffected. An additional action of tretinoin may involve keratinization inhibition, which would explain its effectiveness in treating keratinization disorders.

Pharmacokinetics

Clindamycin phosphate and tretinoin combination products are applied topically to the skin.

Topical Route

Clindamycin: Topical clindamycin has been shown to be systemically absorbed, but the amount is minimal. Clindamycin phosphate appears to be less well absorbed through the skin than is the hydrochloride. In an open-label, multiple-dose study (n=12) using clindamycin phosphate; tretinoin gel, clindamycin plasma concentrations generally did not exceed 3.5 ng/mL, with the exception of one subject whose plasma concentration reached 13.1 ng/mL. In another open label, multiple-dose study (n=17), all clindamycin plasma concentrations were <= 5.56 ng/mL on day 5, except for 1 patients with a maximum concentration of 8.3 ng/mL at 4 hours after the dose.
Tretinoin: Following topical application, a minimal amount of drug is absorbed systemically. In an open-label, multiple-dose study (n=12) using clindamycin phosphate; tretinoin gel, quantifiable tretinoin plasma concentrations ranged from 1 to 1.6 ng/ml; 50—92% of subjects had unquantifiable tretinoin plasma concentrations at any given time point following administration. Key tretinoin metabolites had plasma concentrations ranging from 1 to 1.4 ng/mL for the 13-cis-retinoic acid metabolite and from 1.6 to 6.5 ng/mL for the 4-oxo-13-cis-retinoic acid metabolite. In another open label, multiple-dose study (n=17), there was no appreciable increase in systemic tretinoin exposure as compared to baseline. The average concentration on day 5 ranged from 1.19—1.23 ng/mL as compared to the corresponding baseline of 1.16—1.3 ng/mL.

Pregnancy And Lactation
Pregnancy

There are no well-controlled studies of clindamycin; tretinoin use in pregnant women. Use clindamycin; tretinoin during pregnancy only if the potential benefit justifies the potential risk to the fetus. Animal studies have not shown maternal or developmental toxicity and have revealed no evidence of teratogenicity associated with the topical combination. However, teratogenic effects have been temporally associated with another topical formulation containing tretinoin.

The manufacturer recommends that clindamycin; tretinoin should be used cautiously in women who are breast-feeding. It is not known whether clindamycin or tretinoin are excreted into human milk after topical application. Orally and parenterally administered clindamycin has been reported to appear in breast milk, but minimal systemic absorption occurs after topical administration. Clindamycin is generally considered to be usually compatible with breast-feeding by the American Academy of Pediatrics (AAP). Systemic absorption of tretinoin after topical application is low and therefore it is unlikely that a significant amount of the drug is excreted into breast-milk. Only water-miscible cream products should be applied to the breast because ointments may expose the infant to high levels of mineral paraffins. Consider the benefits of breast-feeding, the risk of potential infant drug exposure, and the risk of an untreated or inadequately treated condition. If a breast-feeding infant experiences an adverse effect related to a maternally administered drug, healthcare providers are encouraged to report the adverse effect to the FDA.