Which drug is taken orally for more severe forms of psoriasis?

Methotrexate is often prescribed as an effective oral treatment option for more severe forms of psoriasis. This drug works by inhibiting rapidly dividing cells, which is a characteristic of psoriasis, where skin cells multiply excessively. Methotrexate exerts its effect by interfering with the metabolism of folic acid, which is necessary for DNA synthesis and cell proliferation.

In severe psoriasis cases, where topical treatments may not suffice, methotrexate can significantly reduce the severity of symptoms and improve the quality of life for patients. It is important to monitor patients on methotrexate due to potential adverse effects, including liver toxicity and bone marrow suppression, underscoring the need for regular follow-up and lab tests.

In contrast, the other options mentioned are primarily topically administered or have different mechanisms that do not typically address severe cases of psoriasis as effectively as methotrexate does. While etanercept is a biologic that can be taken as an injection, calcipotriene is a vitamin D analog used topically, and tazarotene is a topical retinoid. These treatments can be beneficial for managing psoriasis but may not be sufficient for more severe manifestations.