Drug Interactions in the Elderly With Coronary Artery Disease - Do These Interfere With Effective Therapy?

Older patients with cardiovascular disease receive multiple cardiac medications and often have multiple medical conditions for which they receive additional medical therapy. Over-the-counter medications are also frequently used in this older population. These factors coupled with altered drug elimination and potential alterations in drug responses in the elderly patient lead to increased opportunities for adverse drug interactions. In addition to the general geriatric dosing guidelines of starting medications at lower doses, increasing doses slower than in younger patients, and using as few drugs as possible, a framework for understanding drug-drug interactions is presented. Pharmacokinetic drug interactions alter drug concentrations and can either increase or decrease drug concentrations. Pharmacodynamic drug interactions alter the effects of the drug and can produce either additive or antagonistic effects. Examples of each interaction type are presented and currently available data on interactions of cardiovascular drugs with other drugs commonly administered in the elderly are briefly reviewed.