Soritin25 mg

Established / Approved Use

• Severe psoriasis: Soritin is indicated for the treatment of severe, extensive psoriasis in adults, including plaque, pustular (including generalized/palmo-plantar pustular psoriasis), and erythrodermic forms that are resistant to other systemic therapies or topical treatment.

Guideline-Supported / Adjunct Uses

• Used as monotherapy or in combination with phototherapy (Re-PUVA) for extensive plaque or pustular psoriasis, which can allow lower doses of both agents.
• Maintenance therapy in chronic, relapsing psoriasis under specialist (dermatologist) supervision.

Off-Label / Other Disorders of Keratinization (commonly used, evidence-based but outside the core psoriasis label)

• Severe congenital ichthyoses (e.g., lamellar ichthyosis, congenital ichthyosiform erythroderma).
• Darier's disease (keratosis follicularis).
• Other severe disorders of keratinization such as palmoplantar keratoderma, pityriasis rubra pilaris, and lichen planus (in refractory cases), when prescribed by a specialist.

Note: Soritin must only be prescribed by, or under the supervision of, a physician experienced in the use of systemic retinoids, because of its serious teratogenic risk (see Contraindications and Pregnancy & Lactation).

Each capsule contains Acitretin as the active pharmaceutical ingredient, commonly available in strengths of 10 mg and 25 mg. Inactive ingredients typically include gelatin capsule shells and excipients such as sorbitol, maltodextrin, and, in some formulations, parabens as preservatives (relevant for patients with paraben hypersensitivity).

Soritin is a second-generation, synthetic oral retinoid (a metabolite of etretinate) chemically related to vitamin A. It is used to treat severe, treatment-resistant forms of psoriasis and certain other disorders of skin keratinization. Soritin works by normalizing the abnormal growth and maturation of skin cells (keratinocytes) that underlie these conditions.

Soritin carries a boxed warning for severe birth defects (teratogenicity) and must be used only under close medical supervision, with mandatory pregnancy prevention measures in women of childbearing potential.

Soritin belongs to the class of systemic (oral) retinoids, used in dermatology for severe keratinization and psoriatic disorders.

Mechanism of Action

Acitretin is a retinoid that binds to and activates nuclear retinoic acid receptors (RARs), which regulate gene transcription controlling epidermal cell growth, differentiation, and keratinization. This normalizes the excessive proliferation and abnormal differentiation of keratinocytes seen in psoriasis and disorders of keratinization, and produces anti-inflammatory and immunomodulatory effects in the skin.

Pharmacokinetics

• Absorption: Enhanced when taken with food (a fatty meal increases bioavailability substantially); peak plasma concentrations occur within 2–5 hours.
• Distribution: Highly protein-bound (>99%); accumulates in fatty tissue.
• Metabolism: Hepatic; can be converted to etretinate, particularly in the presence of alcohol. Etretinate has an extremely long elimination half-life (up to 120 days), which underlies the prolonged pregnancy-prevention requirement after stopping Acitretin.
• Elimination half-life of Acitretin itself: Approximately 50 hours (2 days).
• Excretion: Via bile/feces and urine as metabolites.

Soritin should be taken orally, once daily, with a meal or with milk to improve absorption. Swallow the capsule whole; do not open, crush, or chew it.

Contraindicated Combinations

• Methotrexate: Concurrent use is contraindicated due to markedly increased risk of hepatotoxicity.
• Tetracyclines: Concurrent use is contraindicated due to increased risk of benign intracranial hypertension (pseudotumor cerebri), which can present with severe headache and visual disturbance.
• Other retinoids/high-dose vitamin A: Avoid concurrent use due to additive risk of hypervitaminosis A toxicity.

Clinically Significant Interactions Requiring Caution

• Alcohol: Promotes conversion of Soritin to etretinate, a metabolite with a very long half-life, prolonging teratogenic risk; alcohol must be avoided during treatment and for 2 months after stopping Soritin (see Precautions).
• Progestin-only ("mini-pill") oral contraceptives: Reliability may be reduced; a combined estrogen-progestin contraceptive or non-hormonal barrier method is preferred during Soritin therapy.
• Phenytoin: Soritin is highly protein-bound and may displace or interact with other highly protein-bound drugs; monitor as clinically indicated.
• Glyburide (and other sulfonylureas): Rare reports of altered glycemic control; monitor blood glucose in diabetic patients.

Very Common (largely dose-related, mucocutaneous)

• Cheilitis (dry, cracked lips) — occurs in the majority of patients
• Dry skin, skin peeling (especially palms and soles), and dry mucous membranes
• Dry, irritated eyes; reduced tolerance to contact lenses
• Dry nasal mucosa, occasional nosebleeds
• Hair thinning/alopecia (usually reversible after stopping treatment)
• Pruritus (itching)

Common

• Elevated blood triglycerides and/or cholesterol
• Elevated liver enzymes
• Paronychia (nail fold inflammation), nail fragility
• Increased sun sensitivity (photosensitivity)
• Joint or muscle aches

Uncommon/Rare but Serious

• Pseudotumor cerebri (benign intracranial hypertension) — severe headache, nausea, visual changes; seek urgent care
• Skeletal changes (hyperostosis) with long-term use
• Night blindness (impaired dark adaptation)
• Mood changes, depression (rare; monitor and report promptly)
• Severe hepatotoxicity (rare)

Patients should report severe headache, visual disturbance, mood changes, or yellowing of the skin/eyes promptly to their physician.

Soritin is absolutely contraindicated in pregnancy. It is a potent human teratogen; use during pregnancy carries a very high risk of serious birth defects (craniofacial, cardiac, thymic, and central nervous system malformations) and miscarriage.

Because Soritin can be converted in the body to etretinate — a metabolite with an extremely long elimination half-life (potentially exceeding 100 days), especially when alcohol is consumed — women of childbearing potential must use effective contraception for at least 1 month before starting treatment, throughout treatment, and continuously for 3 years after stopping Soritin. Two reliable, simultaneous forms of contraception are generally recommended, and alcohol must be strictly avoided during this same period.

Soritin is also contraindicated during breastfeeding, as it is expected to pass into breast milk and could harm the nursing infant. A woman who becomes pregnant while taking Soritin, or within 3 years of stopping it, should contact her physician immediately.

Blood donation is prohibited during Soritin treatment and for 3 years afterward, because of the risk of exposing a pregnant transfusion recipient.

Boxed Warning: Teratogenicity

Soritin must not be used by anyone who is pregnant or who may become pregnant, given the extremely high risk and severity of birth defects. Prescribers and patients must strictly follow pregnancy-prevention requirements (see Pregnancy and Lactation and Contraindications). Soritin should only be prescribed by physicians experienced in systemic retinoid therapy and aware of the teratogenic risk.

Alcohol

Alcohol (including in foods, medicines, and cosmetics applied to the lips) must be avoided during Soritin treatment and for 2 months after stopping, as it promotes conversion of Soritin to etretinate, extending the teratogenic risk window.

Hepatic and Lipid Monitoring

Liver function tests (at baseline, then periodically, e.g. every 1–2 weeks initially then monthly) and fasting lipid profile (baseline, then periodically) should be monitored throughout treatment, as Soritin can cause hepatotoxicity and elevated triglycerides/cholesterol.

Bone/Skeletal Effects

Long-term use has been associated with skeletal hyperostosis; periodic monitoring may be considered with prolonged therapy.

Vision and Mental Health

Report any severe headache, nausea, or visual disturbance immediately (possible pseudotumor cerebri); report mood changes or depressive symptoms to the physician.

Blood Donation

Patients must not donate blood during treatment and for 3 years after stopping Soritin.

Photosensitivity

Use sun protection, as Soritin can increase skin sensitivity to sunlight.

Acute overdose with Soritin may cause symptoms of hypervitaminosis A, such as severe headache, dizziness, nausea, vomiting, drowsiness, or irritability. There is no specific antidote. If an overdose is suspected, seek immediate medical attention or contact a poison control center; treatment is supportive and symptomatic under medical supervision. Do not attempt to manage a suspected overdose at home.

Store at room temperature (below 30°C), away from light and moisture. Keep out of reach of children.

Pediatric Use

Soritin is not approved for the treatment of psoriasis in children. Use in children for severe, disabling disorders of keratinization is off-label, reserved for specialist care when benefits clearly outweigh risks, using conservative weight-based dosing. Long-term safety, including effects on bone growth, has not been fully established in this population.

Elderly

No specific dose adjustment is established for elderly patients, but they should be monitored closely for hepatic, renal, and lipid abnormalities, and for skeletal effects with long-term use.

Hepatic Impairment

Contraindicated in severe hepatic impairment (see Contraindications); use with caution and close monitoring in mild-to-moderate impairment.

Renal Impairment

Contraindicated in severe renal impairment; use with caution in mild-to-moderate impairment, with monitoring.

Women of Childbearing Potential

Must strictly comply with pregnancy-prevention measures before, during, and for 3 years after treatment (see Pregnancy and Lactation).

Initial response to Soritin is generally assessed after 2–4 weeks; treatment commonly continues for 6–8 weeks or longer depending on response. For chronic or relapsing psoriasis and disorders of keratinization, longer-term or repeated courses may be used under continued specialist supervision, with regular monitoring of liver function, lipids, and (with prolonged use) skeletal status. The treating physician determines the total duration based on response and tolerability.

Acitretin is classified as a systemic (oral) retinoid, a synthetic vitamin A derivative used in dermatologic therapy.

Acitretin binds nuclear retinoic acid receptors (RARs) to modulate gene expression, normalizing keratinocyte proliferation and differentiation and reducing the epidermal hyperproliferation and inflammation characteristic of psoriasis and related keratinization disorders.

X

Soritin is not approved for pediatric psoriasis. Its use in children is generally limited to severe, disabling inherited disorders of keratinization (e.g., severe congenital ichthyosis) under the supervision of a specialist, using cautious weight-based dosing (approximately 0.5 mg/kg/day). Safety and efficacy in children have not been formally established for most indications, and long-term effects on bone growth and development are not fully known, so use requires careful risk-benefit assessment and ongoing monitoring by the treating specialist.