What it's for (Indications)
- Acitretin is indicated for severe refractory psoriasis (characterized by marked redness and itchy patches), palmoplantar pustulosis (skin condition involving the palms and soles), and Darier's disease (a skin disorder).
Dosage Information
| Type | Guideline |
|---|---|
| Standard | Therapy should be initiated at 25 to 50 mg per day, administered as a single dose with the main meal. Maintenance doses of 25 to 50 mg per day may be given, adjusted based on individual patient response to achieve a sufficient therapeutic effect while minimizing side effects. Relapses can be managed following the same initial therapy guidelines. When used with phototherapy, the prescriber should decrease the phototherapy dose based on patient response. |
Safety & Warnings
Common Side Effects
- A wide spectrum of signs and symptoms primarily of the mucocutaneous (e.
- g.
- , dry skin, dermatitis, sticky skin, erythema), musculoskeletal, hepatic, neuropsychiatric, and central nervous systems, resembling hypervitaminosis A syndrome.
- Severe adverse reactions reported include acute myocardial infarction, thromboembolism, stroke, hypersensitivity (including angioedema and urticaria), and myopathy with peripheral neuropathy.
Serious Warnings
- Black Box Warning: Acitretin is absolutely contraindicated in females who are pregnant, intend to become pregnant during therapy, or at any time for at least 3 years following discontinuation of therapy. It must also not be used by females who are unable to use reliable contraception during treatment and for at least 3 years post-treatment discontinuation. Acitretin is a known teratogen, being a metabolite of etretinate (TEGISON), and major human fetal abnormalities have been reported.
- Acitretin is absolutely contraindicated during pregnancy and should not be used by breastfeeding mothers.
- Patients with severe liver or kidney dysfunction should not use acitretin; hepatotoxicity is a known risk.
- Alcohol use should be limited or avoided.
- Caution is advised for patients with chronic abnormally elevated blood lipid values or a history of cardiovascular events (e.
- g.
- , acute myocardial infarction, thromboembolism, stroke).
- Concomitant use with methotrexate or tetracyclines is contraindicated due to increased risk of hepatitis and pseudotumor cerebri/increased intracranial pressure, respectively.
- Patients with hypersensitivity to acitretin or its components should avoid its use.
- If taking other vitamins (especially high-dose Vitamin A or retinoid supplements), nutritional supplements, or herbal products, consult a doctor.
- Patients using acitretin with phototherapy require dose adjustment of phototherapy.
- Females with a history of etretinate (TEGISON) use must adhere to its contraceptive guidelines.
- Consult a doctor immediately if swelling is experienced.
- No risks associated with driving have been reported.
How it Works (Mechanism of Action)
Acitretin, a synthetic retinoid and an oral analog of retinoic acid, exerts its therapeutic effects primarily by modulating the proliferation, differentiation, and keratinization of epithelial cells. Its mechanism involves binding to and activating specific nuclear retinoic acid receptors (RARs) and retinoid X receptors (RXRs). These receptors, once activated, form heterodimers and bind to retinoic acid response elements (RAREs) in the promoter regions of target genes, leading to transcriptional regulation and altered gene expression. In conditions characterized by epidermal hyperproliferation and abnormal differentiation, such as severe psoriasis and other disorders of keratinization, acitretin works to normalize these pathological processes. It inhibits the excessive proliferation of keratinocytes, promotes their proper differentiation, and exerts anti-inflammatory effects, thereby restoring a more physiological epithelial growth pattern and reducing the characteristic scaling and thickening of the skin. The precise molecular pathways are intricate and involve downstream effects on numerous cellular signaling cascades, but the overarching outcome is a corrective influence on epidermal dynamics and cellular maturation. This targeted action helps to resolve the underlying cellular abnormalities associated with these dermatological conditions, leading to symptomatic improvement and disease remission.
Concurrently, a calcium supplement, such as that derived from plant sources (e.g., *Algae calcareas* like in Plantcal), provides an essential mineral crucial for a multitude of biological functions. Calcium's mechanism of action as a supplement is to replenish and maintain adequate systemic calcium levels. Once ingested, the calcium ions are absorbed predominantly in the small intestine through both active, vitamin D-dependent transport and passive diffusion. Following absorption, calcium is utilized throughout the body for critical physiological processes, including bone mineralization, where it serves as a primary structural component, maintaining bone density and strength. Furthermore, it is indispensable for neuromuscular function, cardiac contractility, blood coagulation pathways, and intracellular signaling as a secondary messenger. In the context of long-term acitretin therapy, while not a direct pharmacological interaction, adequate calcium intake is important for overall bone health maintenance and to mitigate potential, albeit rare, effects on bone metabolism, ensuring comprehensive patient well-being and supporting the body's fundamental mineral requirements for skeletal integrity and numerous physiological processes.