1/2. intestinal pseudo-obstruction caused by diltiazem in a neutropenic patient.OBJECTIVE: To describe a case of diltiazem-induced intestinal pseudo-obstruction in a neutropenic patient. CASE SUMMARY: A 74-year-old male with newly diagnosed acute myelogenous leukemia developed atrial fibrillation on day 12 of induction chemotherapy. He was initially treated with diltiazem 5 mg intravenously every 5-10 minutes for 5 doses and an amiodarone 150-mg loading dose intravenously. diltiazem 30 mg orally 4 times daily and amiodarone continuous infusion were started thereafter. amiodarone therapy was discontinued after one day due to an untoward adverse effect. The diltiazem dose was then escalated. By day 14, the patient was receiving diltiazem 120 mg orally 4 times daily. On day 15, he developed increasing abdominal distention with hyperactive bowel sounds. On day 16, a radiographic examination showed multiple dilated loops of both the small and large bowel representing possible intestinal pseudo-obstruction; diltiazem was discontinued that day. Starting on day 18, the patient showed recovery of intestinal pseudo-obstruction without intervention. No further GI complications developed during his remaining hospital course. DISCUSSION: intestinal pseudo-obstruction is usually associated with underlying medical conditions such as trauma, infection, cardiac disease, and after surgery. Medications rarely cause such a condition. Detailed examination of the patient's record indicated neither infection nor other medications contributed to the development of intestinal pseudo-obstruction. Additionally, a radiographic examination ruled out neutropenic enterocolitis, a common gastrointestinal complication in neutropenic patients. Use of the Naranjo probability scale indicated a probable relationship between pseudo-obstruction and diltiazem in this patient. CONCLUSIONS: Although calcium-channel blockers rarely cause intestinal pseudo-obstruction, clinicians must be aware of this serious but reversible adverse effect.- - - - - - - - - - ranking = 1keywords = probability (Clic here for more details about this article) |
2/2. Probable propafenone-induced transient global amnesia.OBJECTIVE: To describe a probable case of transient global amnesia caused by propafenone. This adverse effect has not been previously described for this agent. CASE SUMMARY: A 61-year old man with a history of sick sinus syndrome with persistent atrial fibrillation and infrequent premature ventricular contractions was admitted to the hospital for symptoms of amnesia and disorientation to time, place, and date. He began taking propafenone only 6 days prior to admission because of uncontrolled atrial fibrillation and symptoms of fatigue. His atrial fibrillation subsequently had converted to normal sinus rhythm while he received propafenone without adverse effects prior to this episode. His symptoms of amnesia resolved approximately 6-7 hours after discontinuing the propafenone therapy. DISCUSSION: propafenone is a class 1C antiarrhythmic agent that blocks fast sodium channels in heart muscle and purkinje fibers similar to the action of encainide and flecainide. It also produces weak beta- and calcium-channel blockade. It has a significant adverse effect profile, with 30-45% of patients reporting cardiac adverse effects and 15-20% experiencing noncardiac events. central nervous system effects that parallel amnesia have been reported in 10-15% of the patients, including dizziness, ataxia, drowsiness, fatigue, confusion, and paranoia. propafenone's distribution, clearance, and structural similarity to propranolol contribute to its central nervous system effects. CONCLUSIONS: The rapid resolution of this patient's symptoms after discontinuing propafenone therapy and the absence of recurrence lend credence to the probability of this effect. Comparable adverse effects, such as disorientation and temporary amnesia, have been reported in patients in the analogous agent, propranolol. Consequently, this is a likely, although rare, possible adverse effect with propafenone for which patients should be monitored.- - - - - - - - - - ranking = 1keywords = probability (Clic here for more details about this article) |