Monday, June 15, 2009

Monday June 15, 2009
drug-drug interaction

Case; 74 year old male with chronic renal failure admitted to ICU after a seizure episode requiring intubation for airway protection. You started pepcid (femotidine) as GI prophylais. What should you watch closely?



Answer:
Dilantin level

The mechanism of interaction is unknown. Elderly patients with renal failure seems to be on high risk though. Signs of dilantin toxicity includes ataxia, incoordination, tremor, nystagmus, hypotension, slurred speech, lethargy, nausea, vomiting, mental confusion, and psychosis.

Other medications which may affect phenytoin level beside H2-blockers includes carbamazepine, Depakote, phenobarbital, trazodone, isoniazid (INH), sulfonamides (a class of antibiotics), calcium containing antacids, H2 blockers, sucralfate, alcoholic beverages, amiodarone, chloramphenicol, and oral contraceptives.