Geriatric pharmacology for the dentist. An overview.
The information presented in this article suggests that the drug responses of the elderly may be greater than those in the young or essentially the same. We have presented evidence that the pharmacokinetics in the elderly would probably tend toward prolonging the half-life and delaying the clearance of many drugs. Pharmacodynamic changes are more ambiguous, increasing sensitivity to some drugs and decreasing sensitivity to others. Compliance errors, from whatever cause, lead to unpredictable intake of drugs. Psychosocioeconomic factors contribute to compliance errors and no doubt also lead to increased intake of combination of drugs. Multiple diseases are common among the elderly, but it is not clear how disease states, per se, affect drug responses unless the specifically diseased organ is focally important in the handling of drugs. Alterations in perception of pain and in reflex and immune competence will produce changes in all directions. Use of multiple drugs almost certainly will create an environment favorable to drug interactions and adverse reactions. What is the dentist to do with these conflicting effects of aging in drug therapy? There are a few, and only a few, rules that can be said to have a solid basis in fact. Elderly patients seem to be more sensitive to the depressant effects of drugs. It is wise, therefore, to reduce the dosage of such drugs as the benzodiazepines, general anesthetics, analgesics, and sedative-hypnotics in the elderly. Old people are apparently more sensitive to certain drugs, for example, the neuromuscular blocking drugs. It would be wise to reduce the dosage of these for the older patient. The geriatric person appears to be less sensitive to pain; it would be wise to prescribe analgesics for such patients in lower doses. Elderly patients are known to have lost some of their reflex ability to maintain homeostasis. This should be taken into consideration when drugs that affect blood pressure, heart rate, and smooth muscle tone are used. Elderly patients are almost certain to be taking multiple medications. Drug interactions, as well as adverse drug reactions (which are exaggerated in the elderly), are likely to occur in this polypharmaceutical setting. It is critical that the dentist be continually informed of the pharmacologic status of each patient and be aware of the likelihood of interactions between drugs prescribed by the dentist, drugs-prescribed by the physician, and drugs that are self-administered.