A:  Drug interactions occur when one drug affects the actions of another - an increase or decrease in activity or an all together different action.  Sometimes drug interactions can be merely bothersome, but other times potentially harmful.  And, some drugs are purposely combined to increase effectiveness, for example clavulanic acid is combined with amoxicillin to increase the antibiotic’s action.  There is no specific information on how common drug interactions are, but each time you take more than one drug you have a risk for drug interactions.  Your family history, your overall health, the drug’s characteristics, and the dosage are all important factors, and don’t forget that drug interactions can occur with non prescription drugs, foods, and alcohol.