Zopiklon

Additional information

Pharmacokinetics and dosing

Zopiclone has a half-life of 3.5-6 h. No differences in zopiclone pharmacokinetics have been seen between men and women [3].The absorption of zopiclone is similar in men and women and no sex differentiation in dosing has been recommended by the pharmaceutical company [4].

Effects

No studies with a clinically relevant sex analysis regarding the effects of zopiclone have been found.

Adverse effects

In a study of driving capacity after medication with sleeping pills (9 men, 14 women) zopiclone 7.5 mg, but not zolpidem 10 mg, was found to increase the number of collisions in a driving simulator compared to placebo. No analysis based on patient’s sex was performed probably due to the low number of study participants [1]. Also another study showed that zopiclone 7.5 mg, but not zolpidem 3.5 mg (administered 3 hours before driving), impaired next-day driving, but with no differences between men and women [2].However, pooled data from four placebo-controlled studies (in all 50 men, 51 women) on the effects of zopiclone 7.5 mg on driving performance showed no differences between men and women [5]. A review article concludes that no difference in driving performance the day after intake of zopiclone 7.5 mg could be observed between healthy men and women [6].

Reproductive health issues

Regarding teratogenic aspects, please consult Janusmed Drugs and Birth Defects (in Swedish, Janusmed fosterpåverkan).

Other information

Two large register-based studies analyzing utilization of zopiclone in men and women (aged ≥75 years) in Sweden showed that men were more likely than women to dispense zopiclone [7, 8]. However, aggregated data from the Swedish Board of Health and Welfare shows that utilization of zopiclone has been higher among women than men (aged ≥ 75 years) in Sweden every year since 2006. A possible explanation to the different findings could be that the two studies focused on shorter time periods (3 and 4 months), while the aggregated data is based on one year data and the two Swedish studies were conducted only during the year 2005 [9]. In large register-studies from Denmark and Norway, women dispensed more prescriptions of zopiclone and zolpidem in the years 2004 and 2006, respectively [10, 11]. In a Canadian questionnaire study from 2003 (518 men, 941 women), no sex differences in prescribing patterns of zopiclone were observed [12].