UI - 000100

AU - Herrmann WM

AU - Kern U

AU - Aigner M

TI - On the adverse reactions and efficacy of long-term treatment with flupirtine: preliminary results

of an ongoing twelve-month study with 200 patients suffering from chronic pain states in arthrosis or

arthritis

AB - In order to investigate the efficacy and safety of long-term treatment with flupirtine in patients with

chronic pain, in particular arthrosis and arthritis, a study was planned which, when completed, will

encompass the treatment of 200 patients over a 12-month period. The present paper is a preliminary report

of this ongoing study. The report deals with 104 patients: 55 of whom completed the 12-month treatment

period and a 2-week follow-up phase, during which flupirtine was replaced by placebo in order to be able to

detect drug-withdrawal effects. Forty nine patients withdrew from the study. Most of the patients were

suffering from degenerative rheumatic arthrosis or inflammatory rheumatic arthritis. The average daily

dosage was 300 mg. The incidence of drop-outs was highest in the first months with hardly any patients

withdrawing in the last six months. Fifteen patients dropped out because of side effects (dizziness, nausea,

sleep disturbances, and headache). Ten patients dropped out because of ineffectiveness, seven because of

side effects plus ineffectiveness, and three because of side effects and other reasons. The remaining 14

patients dropped out because of other or non-medical reasons. For the 55 patients who completed the study,

the analgesic took effect within 45 minutes to 2 hours, the duration of effect was 4-6 hours. Three-quarters

of the patients responded to the drug, one-quarter did not. The analgesic effect remained constant during the

12-month treatment, as did the average number of capsules taken per month. There was no evidence that

tolerance developed. The most frequent side effects were drowsiness (9% of patients), dizziness (11%), dry

mouth (5%) and pruritis (9%). The withdrawal symptom scale completed every month during treatment (to

determine baseline values) and every day throughout the 2-week placebo post-treatment phase showed no

changes in the median. The mean value increased during the withdrawal phase, however, indicating that the

symptomatology was more pronounced in some subjects. After withdrawal, the non-specific symptoms

increased to a greater extent than symptoms from the opiate scale. The symptoms were present throughout

the withdrawal phase. If the withdrawal phenomena had corresponded to the flupirtine's terminal half-life,

then the symptoms ought to have been present mainly in the first few days. There was a slight trend for

lowering systolic blood pressure but no changes in diastolic blood pressure or heart rate, nor changes in the

ECG or laboratory analysis that could be related to flupirtine.(ABSTRACT TRUNCATED AT 400

WORDS)

SO - Postgraduate Medical Journal 1987;63 Suppl 3:87-103