The MHRA has announced the Europe-wide suspension of the Marketing Authorisation for rimonabant▼ (Acomplia®) following recommendations from the EMEA’s Committee for Medicinal Products for Human Use (CMHP). The CMHP analysed the benefits and risks associated with rimonabant and found that there was approximately a doubling of the risk of psychiatric disorders in obese or overweight patients taking rimonabant compared with those taking placebo. They concluded that the risks of treatment outweighed the benefits.
The MHRA has issued the following advice for healthcare professionals and patients:
- Prescribers should not issue any prescriptions for rimonabant, and should review the treatment of those who are currently taking this medicine.
- Patients who are currently taking rimonabant should consult their doctor or pharmacist at a convenient time to discuss their treatment. If patients wish to stop taking rimonabant, it is safe to do so at any time.
- Patients who are currently enrolled in clinical trials of rimonabant may wish to contact the trial investigator (the doctor who is treating them), who will be able to give more information. Trial investigators are being notified of this suspension of the marketing authorisation.
What is the background to this?
Rimonabant was licensed in the European Union for adjunctive use in the treatment of obesity in June 2006. In July 2007 the MHRA warned that it must not be used by patients with major depression or those being treated with antidepressants, because of the risk of psychiatric adverse effects. They reported that around one in ten people who take rimonabant experience psychiatric side effects, mainly low mood and depression, and approximately one patient in every hundred may experience suicidal thoughts (see blog No. 32 and MeReC Extra No. 32).
Subsequently, the May issue of Drug Safety Update again warned that depressive reactions may occur in up to 10% of patients treated with rimonabant. Prescribers were encouraged to take a detailed history from patients before prescribing rimonabant to assess risk factors for psychiatric reactions, particularly depression. However, the MHRA noted that depressive reactions have also occurred in patients who have no obvious risk factors, apart from obesity itself (see blog No. 113).
In its recent analysis, the CHMP considered data from post-marketing experience and ongoing clinical trials and concluded that serious psychiatric disorders may be more common than in the clinical trials used in the initial assessment of the medicine. They decided that these adverse effects could not be adequately addressed by further risk minimisation measures, since patients who may be at highest risk of psychiatric reactions cannot be identified reliably, and measures implemented to date have not adequately controlled the risk.
In addition, the CHMP noted, that the effectiveness of rimonabant in clinical practice is more limited than was expected on the basis of the clinical trials, because available data indicate that patients generally take the drug only for a short period. Also, they may not maintain the weight loss after stopping treatment.