Opioid therapies and cytochrome p450 interactions.

Adverse drug reactions are common and associated with substantial economic and human costs. Particularly among older adult populations, preventable adverse drug reactions are often caused by drug-drug interactions. All analgesics have side effect profiles and many have known drug-drug interactions. Opioids are recognized as a necessary option for managing moderate-to-severe pain, yet many opioid side effects can be enhanced by metabolic interactions within the liver, involving other drugs, diseases, or genetics.