Interaction between certain psychopharmaca and low-dose oral contraceptives.

The authors wanted to find answers to the question whether certain benzodiazepines and minor tranquillizers decrease the action of low-dose oral contraceptives due to interaction between these drugs by examining 72 women taking these drugs concurrently. Drug interaction causing pregnancy was not observed. Spotting was observed in an extremely high number of cases taking meprobamate or chlordiazepoxide. In 76.9% of these cases causal relation could be proved by the discontinuance of anxiolytic or by changing to another psychopharmacon.