They conducted a retrospective analysis of 13,546 patients with PNDs who had received at least 1 prescription for the tricyclic antidepressant amitriptyline between July 1998 and June 2001. The information was taken from the United Kingdom General Practice Research Database.

Several tricyclic antidepressants are prescribed to control neuropathic pain, but the investigators limited their study to amitriptyline because that was the one used in 95% of the cases under study, said Mugdha Gore, B. Pharm, PhD, principal consultant, Avalon Health Solutions, Inc., Philadelphia, Pennsylvania.

Of those patients, 47% had at least 1 contraindication, warning, or precaution for amitriptyline, or were using at least 1 contraindicated medication concurrently with amitriptyline.

The cohort consisted of 4,516 men and 9,030 women. Forty-eight percent of the women and 43% of the men had a contraindication (P <.0001). Most of the patients (60%) were younger than 65 years and the group overall had a mean age of 59 years. However, patients in the 75-84 year age group were most likely to have at least contraindication to amitriptyline (55%), compared with 43% and 50%, respectively, for patients under 65 years and 65-74 years. Of those who were 85 years or older, 52% had at least 1 preclusion.

Among the contraindications the authors looked for were cardiac risk factors such as history of myocardial infarction, heart block, and congestive heart failure, comorbid mania, and severe liver disease. Warnings/precautions included conditions in which the product label stated that amitriptyline should be "avoided if possible," "used with caution," or "closely monitored." Drugs thought to interact adversely with amitriptyline were also included in the analysis.

The mean initial dose of amitriptyline in these patients was 34 mg, and the mean maintenance dose was 42 mg. Both these doses were lower than the recommended daily doses of 50-150 mg, Dr. Gore pointed out. This might have been the prescribing physicians' way of balancing the potential for pain relief with the risk of adverse effects, she suggested.

"The medications often seemed to be used without looking at the patient's medical profile," Dr. Gore said. "Our findings may underscore a need for physician education in the optimal use of medications for the management of neuropathic pain."


[Presentation title: Use of Amitriptyline in Patients With Painful Neuropathic Disorders in General Practice Settings in the United Kingdom. Poster 191]

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