Use of tricyclic antidepressants in older patients with diabetic peripheral neuropathy

PURPOSE: To describe patterns of use of tricyclic antidepressants (TCAs) (eg, amitriptyline, nortriptyline) among older patients with diabetic peripheral neuropathy (DPN). MATERIALS AND METHODS: Using a large, integrated, US health-insurance claims database, we identified all patients who received TCAs between January 1, 1999 and June 30, 2001 ("study period"). Among these persons, we then selected those who: (1) were aged ≥65 years as of the date of first receipt of a TCA during the study period; and (2) had one or more healthcare encounters with a diagnosis of DPN in the 30-day period immediately preceding date of first receipt of a TCA. We then examined the prevalence of selected comorbidities and concurrent use of medications which might render inappropriate the prescribing of TCAs, based on a listing of contraindications, warnings, and precautions found in the package inserts for these medications. Patterns of TCA prescribing were examined, based on information on paid claims. RESULTS: There were 349 DPN patients, aged ≥65 years, who received TCAs. Mean age was 73.8 years, 55.9% were women, and 17.9% had diagnoses of depression. Most patients (84.0%) began therapy with amitriptyline. Almost one-half of study patients had indicators of potentially inappropriate TCA use, primarily cardiovascular comorbidities. Mean TCA dose among patients with and without these indicators was 23.3 (±13.4) mg and 25.4 (±15.3) mg, respectively (P=0.42). CONCLUSIONS: The high prevalence of contraindications, warnings, or precautions and the low level of TCA exposure suggest that many older patients with DPN who receive TCAs may be inappropriately treated.