dexamethasone + prednisolone

avoid combo: combo may incr. risk of systemic corticosteroid effects, including Cushing syndrome and adrenal suppression, serious infection, GI ulceration, perforation, bleeding, hypokalemia, HTN, other adverse effects (additive effects, duplicate therapy)

donepezil + dexamethasone

monitor bleeding signs/symptoms; in pts with myasthenia gravis, D/C cholinesterase inhibitors at least 24h before starting corticosteroids: combo may decr. donepezil levels, efficacy; may incr. risk of GI ulceration, perforation, bleeding; may cause extreme weakness in myasthenia gravis (hepatic metabolism induced; additive effects; mechanism unknown)

donepezil + prednisolone

monitor bleeding signs/symptoms; in pts with myasthenia gravis, D/C cholinesterase inhibitors at least 24h before starting corticosteroids: combo may incr. risk of GI ulceration, perforation, bleeding; may cause extreme weakness in myasthenia gravis (additive effects; mechanism unknown)

donepezil + benztropine

caution advised: combo may decr. efficacy of both drugs (antagonistic effects)