Rifampin with glucocorticoids

Patients with hypothyroidism who are taking levothyroxine may become hypothyroid if given drugs that decrease T4 absorption (cholestyramine, iron salts, calcium carbonate, aluminum hydroxide, sucralfate, raloxifene, omeprazole, dietary soy and fiber), increase its clearance (phenytoin, car-bamazepine, phenobarbital, rifampin), or decrease T4 to T3 conversion (amiodarone, glucocorticoids, propranolol). 

He developed purpuric lesions on the limbs and then progressively over the entire body. Histopathology showed a leukocytoclastic vascuhtis, and the lesions improved after drug withdrawal and treatment with oral glucocorticoids and antihistamines. The purpura recurred on the right forearm and forehead after separate rechallenges with rifampin 300 mg and pyrazinamide 1500 mg. 

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