Alcohol + Olanzapine - Drug Interactions

Clinical evidence,mechanism, importance and management

The manufacturer says that patients taking olanzapine have shown an increased heart rate and accentuated postural hypotension when given a single-dose of alcohol (See reference number 1). In a study,9 of 11 subjects experienced orthostatic hypotension when they drank alcohol one hour after taking olanzapine 10mg (See reference number 2). No pharmacokinetic interaction has been seen (See reference number 1-3). In practical terms this means that patients should be warned of risk of faintness and dizziness if they stand up quickly. The manufacturers also say that drowsiness is a common adverse effect of olanzapine,and they warn about taking other products that can cause CNS depression, including alcohol (See reference number 3,4). The US manufacturer(See reference number 3) says that patients should not drink alcohol with olanzapine because of potential drowsiness that would result.

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Callaghan JT,Bergstrom RF, Ptak LR, Beasley CM. Olanzapine. Pharmacokinetic and pharmacodynamic profile. Clin Pharmacokinet (1999) 37, 177–93.

Zyprexa (Olanzapine). Eli Lilly and Company. US Prescribing information,November 2006.

Zyprexa (Olanzapine). Eli Lilly and Company Ltd. UK Summary of product characteristics,September 2006.