Acitretin
Also known as: Soriatane · acitretinum · etretin · Ro-10-1670 · Ro-101670/000 · Acetrizoic Acid · Iodophil Viscous
Reviewed by the VetSheet Veterinary TeamUpdated Apr 5, 2026Evidence-based veterinary reference
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Dosing by species
🌎 NA — North America🌍 EU — Europe
Dogs
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Dermatologic conditions where retinoids may be useful | 0.5-1 mg/kg | PO | once daily | — | 🌎 NA |
| Dermatologic conditions where retinoids may be useful | 0.5-2 mg/kg | PO | once daily | — | 🌎 NA |
| Sebaceous adenitis | 0.5-1 mg/kg | PO | once daily | — | 🌎 NA |
Cats
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Actinic keratosis/solar-induced squamous cell carcinoma; or Bowen's Disease | 10 mg per cat | PO | once daily | — | 🌎 NA |
| Bowen's Disease | 3 mg/kg/day | PO | once daily | — | 🌎 NA |
- Actinic keratosis/solar-induced squamous cell carcinoma; or Bowen's Disease: Note: This dose is for etretinate, but as the smallest capsule is 10 mg, this dose may need to suffice as well for cats.
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Overview
Acitretin is a second-generation systemic retinoid and the active metabolite of etretinate.
- Primarily used in veterinary dermatology to manage severe keratinization disorders, sebaceous gland abnormalities, and certain cutaneous neoplasms.
- It replaced etretinate on the human market due to a significantly shorter half-life, reducing the duration of tissue accumulation and associated long-term toxicity.
- Clinical Pearl: While highly effective for conditions like canine lamellar ichthyosis, sebaceous adenitis, and precancerous solar lesions, its use in veterinary medicine is often limited by high cost, teratogenic risks, and the need for compounding to achieve accurate dosing in smaller patients.
Mechanism of action
Acitretin works by interacting with intracellular receptors to modulate cellular differentiation and proliferation.
- Binds to nuclear Retinoic Acid Receptors (RARs) and Retinoid X Receptors (RXRs).
- Receptor-ligand complexes bind to specific DNA sequences → alters gene transcription.
- Pharmacodynamic Effects: Normalizes keratinocyte differentiation, reduces epidermal hyperproliferation, decreases sebum production, and exerts anti-inflammatory and antineoplastic effects (particularly against squamous cell carcinomas).
Safety & warnings
Contraindications
- Pregnancy (absolute contraindication)
- Cardiovascular disease
- Hypertriglyceridemia
- Known sensitivity to acitretin or other retinoids
Adverse effects
- Anorexia
- Vomiting
- Diarrhea
- Cracking of foot pads
- Pruritus
- Ventral abdominal erythema
- Polydipsia
- Lassitude
- Joint pain/stiffness
- Eyelid abnormalities
- Keratoconjunctivitis sicca (KCS)
- Swollen tongue
- Behavioral changes
- Weight loss (especially in cats)
Precautions
TERATOGEN WARNING: Acitretin is a known teratogen (FDA Category X). It should not be handled by pregnant women nor used in a household where women are pregnant or planning to become pregnant.
- Use with caution in patients with renal or hepatic failure.
- May cause significant alterations in lipid profiles (hypertriglyceridemia, hypercholesterolemia) and liver enzymes.
Drug interactions
Acitretin can form etretinate in the presence of alcohol; etretinate is a teratogen with an extremely long terminal half-life that can persist in adipose tissue for years.
May increase the potential for hepatotoxicity.
May cause additive toxic effects.
May increase the potential for the occurrence of pseudotumor cerebri (cerebral edema and increased CSF pressure).
Monitoring
- Clinical efficacy
- Liver function tests (baseline and if clinical signs appear)
- Schirmer tear tests (monthly, especially in older dogs)
- Serum triglycerides and cholesterol (recommended based on human data)
Pharmacokinetics
Absorption
Absorption is enhanced by food in the gut.
Distribution
Highly bound to plasma proteins.
Metabolism
Metabolized to conjugate forms.
Elimination
Excreted in the bile and urine.
Overdose
Information on overdoses with this agent remains limited. One oral overdose (525 mg) in a human patient resulted only in vomiting. The oral LD50 in rats and mice is >4 grams/kg.
Available products
Formulations
- Capsules
Human-labeled
- Acitretin Capsules: 10 mg, 17.5 mg, 22.5 mg & 25 mg (Soriatane)
Regulatory status
No regulatory data for: 🇺🇸 US · 🇪🇺 EU · 🇬🇧 UK · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Store at room temperature and protected from light. After bottle is opened, protect from high temperature and humidity.
Client information
CRITICAL SAFETY WARNING: Acitretin causes severe birth defects. Pregnant women, or women planning to become pregnant, MUST NOT handle this medication. Veterinarians and clients must strictly manage the risk of exposure.
- Administration: Give this medication consistently with food to increase its absorption and effectiveness.
- Side Effects: Monitor your pet for signs of "dry eye" (squinting, thick eye discharge), dry or cracking footpads, vomiting, or loss of appetite.
- Cats: If your cat stops eating or loses weight, contact your veterinarian immediately. The dosing schedule may need to be adjusted (e.g., given every other day).
- Cost: Be aware that long-term therapy with this medication can be quite expensive.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.