Therapeutic efficacy and safety of propylthiouracil in psoriasis: an open-label study

Psoriasis is a common hyperproliferative disorder of the skin associated with significant morbidity. Most of the drugs used in psoriasis provide only a temporary relief, whereas they are riddled with potential toxicities and cost concerns. Hence, there is a constant need to explore newer, effective, orally administered, and cost-effective drugs with minimal adverse effects. In this scenario, propylthiouracil (PTU), an antithyroid thioureylene has been shown to be effective in psoriasis which satisfies the above criteria. The objective of our study is to assess the clinical efficacy of PTU in psoriasis. A total of 25 patients with plaque psoriasis were treated with oral PTU for 12 weeks. Clinical response was assessed using the "Psoriasis Area and Severity Index" (PASI) score. Routine blood analyses and thyroid function tests were carried out periodically during the study. Oral PTU produced significant clearing of lesions at 6 weeks and 12 weeks of the study period in all patients, as demonstrated by the reduction in PASI scores (33.9% in 6 weeks and 74.1% reduction in 12 weeks). Four patients experienced near complete clearing of the lesions. One patient developed mild elevation of liver enzymes which reversed on withdrawal of PTU. None of the patients had hypothyroidism or cytopenias. PTU significantly clears the lesions in psoriasis with minimal adverse effects. Hence, it can be considered as a therapeutic option in psoriasis, especially when the standard drugs cannot be used due to their toxicities or forbidding cost.