Anti-migraine and Antigout drugs MCQs

At doses needed to treat acute gout, colchicine frequently causes significant diarrhea. Such gastrointestinal effects are less likely with the lower doses used in chronic gout. Reference: Basic & Clinical Pharmacology, Fourteenth Edition By Bertram G. Katzung Pg no. 656

Like other weak acids, methotrexate depends on active tubular excretion in the proximal tubule for efficient elimination. Probenecid competes with methotrexate for binding to the proximal tubule transporter and thereby decreases the rate of clearance of methotrexate. Reference: Basic & Clinical Pharmacology, Fourteenth Edition By Bertram G. Katzung Pg no. 647

In this question, you must identify the immunosuppressive drug that interacts with allopurinol, subsequently requiring a dose reduction of the immunosuppressant agent. Azathioprine is an immunosuppressant that ultimately inhibits T-lymphocyte proliferation. This agent is converted to 6-mercaptopurine, which inhibits DNA purine synthesis and subsequent T-cell proliferation. Xanthine oxidase is instrumental in the metabolism of azathioprine metabolites, and coadministration with allopurinol (an inhibitor of xanthine oxidase) can result in azathioprine toxicity. Because azathioprine interacts with allopurinol in the question stem, azathioprine is the correct . Reference- Basic & Clinical Pharmacology, Fourteenth Edition By Bertram G. Katzung Pg no. 1004-1005

Allopurinol is the only drug listed that decreases production of uric acid. Probenecid increases uric acid excretion. Colchicine and hydroxychloroquine do not affect uric acid metabolism. Aspirin actually slows renal secretion of uric acid and raises uric acid blood levels. It should not be used in gout. Reference: Basic & Clinical Pharmacology, Fourteenth Edition By Bertram G. Katzung Pg no. 651

Patient is on SSRI, therefore 5-HT agonist should be avoided as it combination may lead to serotonin syndrome. Serotonergic drugs : Psychiatric drugs: MAOIs, SSRIs, SNRIs, TCAs, vortioxetine, vilazodone, trazodone, buspirone Other drugs: tramadol, ondansetron, MDMA, dextromethorphan, meperidine, St. John's wort, triptans, linezolid. Reference: Basic & Clinical Pharmacology, Fourteenth Edition By Bertram G. Katzung Pg no. 287