Pulse Dosing of Thioguanine in Recalcitrant Psoriasis

6-Thioguanine in the Treatment of Psoriasis: A Case Report and Literature Review

“…In contrast, 6-thioguanine is metabolized in the liver and is not nephrotoxic. 1,5,7 6-Thioguanine is similar to 6-mercaptopurine and acts as an antimetabolite to inhibit DNA synthesis, presumably by inhibition of purine ring synthesis. Still, it is unlikely that the doses of 6-thioguanine used in psoriasis directly influence growth of keratinocytes to produce clinical effects.…”

“…Thirty-five percent of the oral dose is excreted in the urine within 24 hours. [2][3][4][5][6] Case Report A 72-year-old Caucasian male developed pustular psoriasis approximately one year before presentation. The patient's psoriasis was refractory to treatment with numerous topical corticosteroids and topical tars as well as oral antibiotics and phototherapy with ultraviolet B.…”

“…The maximum dose should be 160 mg three times per week. 5 That regimen was used by Silvis in 80 patients who had either failed previous treatments with methotrexate, PUVA, or cyclosporine or could not tolerate methotrexate. Only 2 patients had a drop in platelet count with no clinical consequences.…”

Guidelines of care for the management of psoriasis and psoriatic arthritis

“…In a novel dosing regimen of 6-thioguanine given as pulse dosing, either twice or 3 times per week, 10 of 14 patients showed marked improvement in previously recalcitrant psoriasis. 175 The advantage of this dosing regimen, where patients were given between 120 mg twice per week up to 160 mg 3 times per week, was a marked decrease in bone-marrow toxicity compared with J AM ACAD DERMATOL VOLUME 61, NUMBER 3 daily dosing. 175 Recommendations for the use of 6-thioguanine are shown in Table XIX.…”

Clinical Clearing of Psoriasis by 6-Thioguanine Correlates With Cutaneous T-Cell Depletion via Apoptosis

“…In comparison with methotrexate, 6-thioguanine causes fewer gastrointestinal adverse effects; the rare hepatotoxic effects produced by 6-thioguanine are caused by effects on vascular cells, not hepatocytes. Given its likely mechanism of action, ie, induction of apoptotic death in proliferating T lymphocytes, pulse dosing of 6-thioguanine 54 is quite sensible. Theoretically, pulse administration of 6-thioguanine could produce less hematologic suppression than daily administration and should be investigated further.…”