Current demographic data clearly show that the North American population is aging, and projections suggest that the percentage of older people will increase. The elderly often suffer from multiple chronic conditions that affect their quality of life, use of health services, morbidity and mortality. Also, in those of advanced age, the pharmacokinetics and pharmacodynamics of many drugs are altered. Polypharmacy increases the incidence of adverse drug reactions and drug interactions in this population. Thus, the dentist must be continually aware of the pharmacologic status of each patient and consider the likelihood of interactions between drugs prescribed by the dentist, drugs prescribed by the physician and drugs that are self-administered, including over-the-counter medications and natural supplements. In this article, we discuss pharmacokinetic and pharmacodynamic changes in the elderly patient, polypharmacy and the changes in prescribing for our dental patients. Specific emphasis is placed on the drugs commonly prescribed by dentists: local anesthetics, analgesics and antibiotics.