Drug Side Effects on Elderly

Elderly patients use more medication and suffer from more chronic medical problems than other age groups. Aging affects the pharmacodynamics and pharmacokinetics of medications---or how the drug affects the body and the body affects the drug.

Adverse Drug Effects

• Drug-disease interactions make one medical condition worse through the prescription of a medication for another condition. Elderly patients tend to have multiple conditions, making them particularly susceptible. Anticholinergic medications commonly cause this interaction.

  Drug-drug interactions may also occur more frequently in the elderly because of the slower metabolism of medications.

Effective Drug Therapy

• According to the Merck Manual, a prescription cascade may occur when the prescribing doctor mistakes a drug side effect for a newly presenting medical condition. A medication is prescribed to treat the new condition, possibly causing more side effects to be misinterpreted.

  Dosage in the elderly should begin low and build up to a typical adult dosage. Side effects should be monitored and recorded.

Categories of Concern

• Non-steroidal anti-inflammatory drugs (NSAIDs) may cause gastrointestinal bleeding, renal problems, and heart issues. Over the counter ibuprofen falls within this category.

  Elderly patients have an increased sensitivity to anticoagulants such as warfarin.

Elderly Pharmacodynamics

• Elderly patients, particularly those with dementia, run a higher risk of central nervous system (CNS) side effects of medications. This may cause drowsiness and confusion.

Elderly Pharmacokinetics

• Medication metabolism and excretion lessens with aging. This may cause buildup and toxicity. Lower starting doses may prevent this problem.