Drug Interaction Report

MONITOR: Coadministration of alemtuzumab with drugs that have antiplatelet or anticoagulant effects, such as nonsteroidal anti-inflammatory drugs (NSAIDs), may increase the risk of bleeding. Use of alemtuzumab alone has been associated with autoimmune and hemolytic anemia, thrombocytopenia, prolonged myelosuppression, bone marrow aplasia, hemophilia, and pancytopenia. The mechanism for this interaction has not been clearly delineated, but is presumably due to additive antiplatelet/anticoagulant effects.

MANAGEMENT: Caution is recommended if alemtuzumab is used concomitantly with NSAIDS. Patients should be monitored for increased anticoagulant effects and bleeding complications. Patients should be advised to promptly report any signs of unusual bleeding or bruising to their physician, including pain, swelling, headache, dizziness, weakness, prolonged bleeding from cuts, increased menstrual flow, vaginal bleeding, nosebleeds, bleeding of gums from brushing, red or brown urine, or red or black stools.

GENERALLY AVOID: The concurrent use of aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs) and ethanol may lead to gastrointestinal (GI) blood loss. The mechanism may be due to a combined local effect as well as inhibition of prostaglandins leading to decreased integrity of the GI lining.

MANAGEMENT: Patients should be counseled on this potential interaction and advised to refrain from alcohol consumption while taking aspirin or NSAIDs.

GENERALLY AVOID: Use of anticholinergic agents with alcohol may result in sufficient impairment of attention so as to render driving and operating machinery more hazardous. In addition, the potential for abuse may be increased with the combination. The mechanism of interaction is not established but may involve additive depressant effects on the central nervous system. No effect of oral propantheline or atropine on blood alcohol levels was observed in healthy volunteers when administered before ingestion of a standard ethanol load. However, one study found impairment of attention in subjects given atropine 0.5 mg or glycopyrrolate 1 mg in combination with alcohol.

MANAGEMENT: Alcohol should generally be avoided during therapy with anticholinergic agents. Patients should be counseled to avoid activities requiring mental alertness until they know how these agents affect them.