Safety and tolerance of zolpidem in the treatment of disturbed sleep: a post-marketing surveillance of 16944 cases.

The subjective response to treatment with zolpidem, an imidazopyridine hypnotic, was assessed in patients with insomnia under normal treatment conditions in an outpatients' practice in Germany. The uncontrolled clinical surveillance study included 16944 outpatients with subjective difficulties in initiating and/or maintaining sleep. Office-based neurologists, psychiatrists, internists and general practitioners were asked individually to adjust the dosage of zolpidem (age < or = 65 years, 10-20 mg; age > 65 years, 5-10 mg) over a recommended period of 3-4 weeks. In total, 82.8% of patients completed the survey (36% men, 64% women, mean age 58.8 +/- 14.9 years; 58.6% without previous hypnotic medication; duration of sleep complaints > 6 months in 40.6%, 1-6 months in 27.8%). Most patients (63.9%) took zolpidem on a daily basis. The average dose was 10 mg zolpidem per night in 74.8%, 5 mg in 19.8%, 20 mg in 2.4% and > 20 mg in 10 cases. Most physicians (87.6%) rated the efficacy of zolpidem as 'very good' or 'good'. One hundred and eighty-two (1.1%) of the 16 944 patients reported 268 adverse events (one adverse event in 113 cases, two adverse events in 53 cases and more than two adverse events in 16 cases). One hundred and eighteen (64.8%) of these patients (0.006% of all participating patients) discontinued treatment because of adverse events. Nausea (n = 36), dizziness (n = 35), malaise (n = 23), nightmares (n = 20), agitation (n = 19), and headache (n = 18) were the most common adverse events. There was one serious adverse reaction in a 48-year-old women who developed paranoid symptoms during the documentation phase. No life-threatening adverse event occurred. The adverse event profile reflected the pharmacological properties of zolpidem and underlined the cumulative good experience with the drug internationally.