Usage
Anti-psoriatic medications are primarily used to treat psoriasis, a chronic autoimmune skin condition. Psoriasis causes the rapid buildup of skin cells, leading to thick, red, scaly patches on the skin. These patches can be itchy and painful. Some anti-psoriatics are also used for other skin conditions, like psoriatic arthritis, palmoplantar pustulosis, hand dermatitis, Darier disease, lichen planus, lichen sclerosus, lupus erythematosus, cutaneous T-cell lymphoma, granuloma annulare, severe ichthyosis, actinic keratoses, skin cancers, and extensive warts. The pharmacological classification of anti-psoriatics encompasses several categories, including topical corticosteroids, vitamin D analogues, retinoids, topical immunomodulators (TIMs), and systemic agents like methotrexate and biologics. The mechanism of action varies depending on the specific drug.
Alternate Names
The term “Anti-psoriatic” itself represents a class of drugs, not a single medication. Therefore, there isn’t a single alternate name. However, specific drugs within this class have various generic and brand names. Some examples include:
- Acitretin: Neotigason™, Novatretin®
- Calcipotriene: Sorilux®, Dovonex®
- Tazarotene: Tazorac®
- Methotrexate: (various generic and brand names exist)
How It Works
The pharmacodynamics and pharmacokinetics vary greatly amongst the different anti-psoriatic agents.
- Topical Corticosteroids: Reduce inflammation and suppress the immune response in the skin. They are absorbed systemically, metabolized primarily in the liver, and excreted by the kidneys.
- Vitamin D Analogues: Like calcipotriene, these bind to vitamin D receptors and inhibit keratinocyte proliferation and differentiation, reducing inflammation and plaque formation. They are absorbed topically with minimal systemic effects. Metabolism and excretion pathways are similar to natural vitamin D.
- Retinoids: Such as acitretin, normalize epidermal cell growth and differentiation. Administered orally, acitretin is well absorbed and undergoes hepatic metabolism, including isomerization to its active metabolite. It is excreted via both renal and biliary routes.
- Systemic Agents (e.g., Methotrexate): Inhibit DNA synthesis, impacting rapidly dividing cells like those in psoriatic plaques. Orally administered methotrexate undergoes hepatic metabolism and is primarily excreted renally.
The mode of action differs depending on the agent. Corticosteroids bind to glucocorticoid receptors, vitamin D analogues bind to vitamin D receptors, and retinoids bind to retinoic acid receptors (RARs) and retinoid X receptors (RXRs), ultimately affecting gene transcription related to inflammation and cell growth. Specific enzyme inhibition or neurotransmitter modulation is not a primary mechanism for most anti-psoriatics used in psoriasis.
Dosage
Dosage guidelines depend on the specific anti-psoriatic agent and the severity of the psoriasis.
Standard Dosage
Adults:
- Acitretin: 0.25-1 mg/kg/day orally, usually administered once daily with a fatty meal to enhance absorption. Dosage may be adjusted based on response and tolerability.
Children:
Pediatric dosing must be determined carefully by a dermatologist, considering age, weight, and the specific medication used. Safety and efficacy in children vary significantly between different anti-psoriatic agents.
Special Cases:
- Elderly Patients: Similar to adults, with careful monitoring for side effects and potential drug interactions.
- Patients with Renal Impairment: Dosage adjustments may be necessary for certain systemic agents, based on creatinine clearance.
- Patients with Hepatic Dysfunction: Dosage modification is crucial for medications primarily metabolized by the liver, like acitretin and methotrexate.
- Patients with Comorbid Conditions: Dosage and drug choice must consider potential interactions and effects on other conditions.
Clinical Use Cases
The provided clinical use cases are not directly applicable to anti-psoriatic medications for the treatment of psoriasis. Anti-psoriatics are not typically used in settings such as intubation, surgical procedures, mechanical ventilation, ICU use, or emergency situations like status epilepticus or cardiac arrest. These medications are intended for long-term management of chronic psoriasis.
Dosage Adjustments
Dose modifications are based on patient response, tolerability, renal/hepatic function, drug interactions, and other patient-specific factors. Genetic polymorphisms impacting drug metabolism may also warrant dose adjustments for certain systemic therapies.
Side Effects
Side effects vary widely among different anti-psoriatic drugs.
Common Side Effects
- Topical: Skin irritation, burning, itching, dryness, redness.
- Systemic: Headache, nausea, fatigue, liver enzyme elevations.
Rare but Serious Side Effects
- Acitretin: Teratogenicity, liver toxicity.
- Methotrexate: Bone marrow suppression, liver damage.
Long-Term Effects
- Some systemic agents: Increased risk of infections, certain cancers.
Adverse Drug Reactions (ADR)
Severe ADRs, such as Stevens-Johnson syndrome (SJS) or toxic epidermal necrolysis (TEN), while rare, require immediate discontinuation of the medication and supportive care.
Contraindications
- Acitretin: Pregnancy, breastfeeding, severe liver or kidney impairment.
- Methotrexate: Pregnancy, breastfeeding, active infections, severe immunodeficiency.
Drug Interactions
Consult specific drug information for a complete interaction profile. Some examples:
- Acitretin: Alcohol (may form etretinate, a long-acting retinoid), methotrexate, tetracyclines.
- Methotrexate: Nonsteroidal anti-inflammatory drugs (NSAIDs), certain antibiotics.
Pregnancy and Breastfeeding
Many anti-psoriatics are contraindicated during pregnancy due to potential teratogenic effects (e.g., acitretin, methotrexate). Topical treatments are generally preferred during pregnancy and breastfeeding. However, even with topical agents, caution is advised when applying to the breasts during breastfeeding.
Drug Profile Summary
Since “Anti-psoriatic” refers to a class of drugs, a general summary is presented:
- Mechanism of Action: Varies by drug. Includes reducing inflammation, inhibiting cell proliferation, modulating immune response.
- Side Effects: Vary by drug. May include skin irritation, dryness, headache, nausea, and more severe effects depending on the agent.
- Contraindications: Vary by drug. Many are contraindicated in pregnancy and breastfeeding.
- Drug Interactions: Consult individual drug information.
- Pregnancy & Breastfeeding: Many are contraindicated.
- Dosage: Varies by drug and patient characteristics.
- Monitoring Parameters: Depends on the specific drug; may include liver function tests, complete blood count, lipid profile, renal function tests, and serum calcium levels.
Popular Combinations
- Topical corticosteroids + vitamin D analogues.
- Phototherapy + systemic agents.
Precautions
Pre-screening is essential to identify potential contraindications, such as allergies, organ dysfunction, and pregnancy. Specific precautions exist for different drugs and patient populations, especially pregnant/breastfeeding women, children, and the elderly. Lifestyle factors, like alcohol consumption, may interact with certain anti-psoriatics.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for ANTI-PSORIATIC?
A: Dosage depends on the specific anti-psoriatic medication. Consult individual drug information for specific recommendations.
Q2: What are the common side effects of topical anti-psoriatics?
A: Common side effects of topical treatments include skin irritation, dryness, burning, itching, and redness.
Q3: Can pregnant women use anti-psoriatic medications?
A: Many anti-psoriatics, such as acitretin and methotrexate, are contraindicated during pregnancy due to potential harm to the fetus. Consult a physician for safe alternatives.
Q4: How long does it take for anti-psoriatic treatment to work?
A: The response time varies depending on the medication and the individual. It can take several weeks to months to see significant improvement.
Q5: What are the potential drug interactions with acitretin?
A: Acitretin can interact with alcohol, methotrexate, tetracyclines, and other medications. Avoid alcohol consumption while taking acitretin.
Q6: What should patients do if they experience side effects?
A: Patients should report any side effects to their physician. The doctor can determine if the medication needs to be adjusted or discontinued.
Q7: What are the monitoring parameters for methotrexate?
A: Monitoring parameters for methotrexate include complete blood count, liver function tests, and renal function tests.
Q8: Are there any lifestyle changes that can help manage psoriasis?
A: Yes, lifestyle modifications such as avoiding triggers (stress, infections, certain medications), maintaining good skin hygiene, using moisturizers, and quitting smoking can help improve psoriasis symptoms.
Q9: What are biologics, and how are they used in psoriasis treatment?
A: Biologics are genetically engineered drugs that target specific components of the immune system involved in psoriasis. They are usually reserved for moderate to severe cases that haven’t responded to other treatments.
