Systemic Therapies Protocol

Guidelines for the safe initiation and monitoring of common systemic agents in dermatology.

Methotrexate

Used primarily for severe psoriasis and atopic eczema. It acts as a folic acid antagonist.

• Dosing: Always dosed ONCE WEEKLY. Typical starting dose is 7.5mg to 15mg weekly.
• Folic Acid Supplementation: Required (usually 5mg weekly, taken 24-48 hours after the methotrexate dose) to reduce mucosal and GI side effects.
• Monitoring: FBC, U&E, LFTs every 1-2 weeks until dose stabilized, then every 2-3 months. Monitor for hepatotoxicity and bone marrow suppression.

Cyclosporine

A calcineurin inhibitor offering rapid onset of action. Ideal for acute crisis management of eczema or psoriasis.

• Dosing: 2.5 to 5 mg/kg/day in divided doses.
• Duration: Typically limited to 1 year due to cumulative nephrotoxicity.
• Monitoring: Blood pressure and renal function (eGFR/Creatinine) are critical. If creatinine rises >30% above baseline, the dose must be reduced or stopped.

Acitretin

An oral retinoid used for generalized pustular psoriasis and severe hyperkeratotic conditions.

• Teratogenicity: Highly teratogenic. Strict pregnancy prevention required during treatment and for 3 years after discontinuation.
• Monitoring: Fasting lipids (causes hypertriglyceridemia) and LFTs.