Practical Aspects of Geriatric Pharmacology

PRACTICAL ASPECTS OF GERIATRIC PHARMACOLOGY

The quality of life in elderly patients can be greatly improved and life span can be prolonged by the intelligent use of drugs. However, the prescriber must recognize several practical obstacles to compliance.

The expense of drugs can be a major disincentive in patients receiving marginal retirement incomes who are not covered or inadequately covered by health insurance. The prescriber must be aware of the cost of the prescription and of cheaper alternative therapies. For example, the monthly cost of arthritis therapy with newer NSAIDs may exceed $100, whereas that for generic aspirin is about $5 and for ibuprofen and naproxen, two older NSAIDs, about $20.

Nonadherence may result from forgetfulness or confusion, especially if the patient has several prescriptions and different dos-ing intervals. A survey carried out in 1986 showed that the popu-lation over 65 years of age accounted for 32% of drugs prescribed in the USA, although these patients represented only 11–12% of the population at that time. Since the prescriptions are often writ-ten by several different practitioners, there is usually no attempt to design “integrated” regimens that use drugs with similar dosing intervals for the conditions being treated. Patients may forget instructions regarding the need to complete a fixed duration of therapy when a course of anti-infective drug is being given. The disappearance of symptoms is often regarded as the best reason to halt drug taking, especially if the prescription was expensive.

Nonadherence may also be deliberate. A decision not to take a drug may be based on prior experience with it. There may be excellent reasons for such “intelligent” noncompliance, and the practitioner should try to elicit them. Such efforts may also improve compliance with alternative drug regimens, because enlisting the patient as a participant in therapeutic decisions increases the motivation to succeed.

Some errors in drug taking are caused by physical disabilities. Arthritis, tremor, and visual problems may all contribute. Liquid medications that are to be measured “by the spoonful” are espe-cially inappropriate for patients with any type of tremor or motor disability. Use of a dosing syringe may be helpful in such cases. Because of decreased production of saliva, older patients often have difficulty swallowing large tablets. “Childproof ” containers are often “elder-proof ” if the patient has arthritis. Cataracts and macular degeneration occur in a large number of patients over 70. Therefore, labels on prescription bottles should be large enough for the patient with diminished vision to read or should be color-coded if the patient can see but can no longer read.

Drug therapy has considerable potential for both helpful and harmful effects in the geriatric patient. The balance may be tipped in the right direction by adherence to a few principles:

1. Take a careful drug history. The disease to be treated may be drug-induced, or drugs being taken may lead to interactions with drugs to be prescribed.

2. Prescribe only for a specific and rational indication. Do not prescribe omeprazole for “dyspepsia.” Expert guidelines are published regularly by national organizations and websites such as UpToDate.com.

Define the goal of drug therapy. Then start with small doses and titrate to the response desired. Wait at least three half-lives (adjusted for age) before increasing the dose. If the expected response does not occur at the normal adult dosage, check blood levels. If the expected response does not occur at the appropriate blood level, switch to a different drug.

4. Maintain a high index of suspicion regarding drug reactions and interactions. Know what other drugs the patient is taking, including over-the-counter and botanical (herbal) drugs.

5. Simplify the regimen as much as possible. When multiple drugs are prescribed, try to use drugs that can be taken at the same time of day. Whenever possible, reduce the number of drugs being taken.