Anticholinergic medications in community-dwelling older veterans: prevalence of anticholinergic symptoms, symptom burden, and adverse drug events.

BACKGROUND

The use of drugs with anticholinergic adverse effects is often deemed inappropriate in elderly (aged > or = 65 years) patients, yet studies continue to show extensive use in this population at high risk for adverse drug events (ADEs). The burden of drug-related anticholinergic symptoms in community-dwelling elderly patients has not been well described.

OBJECTIVE

The aim of this study was to assess the prevalence of anticholinergic symptoms, corresponding symptom burden, and anticholinergic-related ADEs in a sample of community-dwelling elderly veterans.

METHODS

This prospective cohort study was conducted at the primary care clinics at the Veterans Affairs Medical Center (VAMC), Iowa City, Iowa. The study sample included randomly selected patients with intact cognitive function attending the VAMC and prescribed > or = 5 scheduled medications. Data on current prescription and nonprescription drug use were elicited by a trained research assistant and a clinical pharmacist from patient interviews and electronic medical records. The prevalence and severity of 7 anticholinergic symptoms (dry mouth, constipation, blurred vision, confusion, urinary hesitation, dry eyes, and drowsiness) were assessed at baseline. The occurrence of ADEs at 12 weeks was compared between patients using anticholinergic drugs and those not using them.

RESULTS

A total of 532 patients were included (97.9% men; mean age, 74.3 years; 27.1% used at least 1 anticholinergic drug). Twenty-two anticholinergic drugs (16 prescription medications, 6 over-the-counter medications) were identified. The mean number of anticholinergic symptoms was significantly higher in the group using anticholinergic drugs (3.1 vs 2.5; P < 0.01). However, only 2 symptoms were statistically more prevalent in the group using anticholinergic drugs: dry mouth (57.6% vs 45.6%) and constipation (42.4% vs 29.4%) (both, P < 0.01). At 12 weeks, only 1 (0.8%) patient in the group using anticholinergic drugs reported an ADE considered related to an anticholinergic drug.

CONCLUSIONS

Anticholinergic drug use was common (27.1%) in these elderly veterans with intact cognitive function. The mean number of anticholinergic symptoms was significantly greater in this group, and the prevalences of dry mouth and constipation were significantly higher in the group using anticholinergic drugs (all, P < 0.01). Anticholinergic-related ADEs were rare (0.8%). Although anticholinergic drugs should generally be avoided in the elderly, individual risks and benefits for a patient should be considered.