Legal category: POM.
Brand name: Acomplia.
Active ingredient: Rimonabant 20 mg.
Description: White tear-drop shaped film-coated tablet marked with strength.
Presentation: 28, £55.20.
Indications: As an adjunct to diet and exercise for the treatment of obese patients (BMI > 30 kg/m2) or overweight patients (BMI > 27 kg/m2) with associated risk factors, such as type 2 diabetes or dyslipidaemia.
Pharmacology: The endocannabinoid (EC) system is responsible for controlling energy balance and regulating body weight, and it is thought that sustained excess food intake is linked to chronic overactivity of the EC system. In animal studies, overactivity of the EC system is associated with increased body weight, increased visceral fat, dyslipidaemia and impaired glucose metabolism.
Two receptors in the EC system have currently been characterised as cannabinoid-1 (CB1) and cannabinoid-2 (CB2). CB1 receptors are integral in the metabolism of glucose and lipids and are located in abdominal fat, the liver, the GI tract, muscle and brain, while CB2 receptors are most commonly found in the immune system.
Rimonabant, a selective CB1 receptor antagonist that acts both centrally and peripherally, has been developed as an effective appetite suppressant for the treatment of obesity.
Following oral administration rimonabant is readily absorbed, with peak plasma concentrations attained within approximately two hours of dosing and steady state plasma levels achieved within 13 days. Rimonabant is highly plasma protein bound and the apparent peripheral volume of distribution is higher in obese patients than in normal weight subjects. It undergoes hepatic metabolism and is primarily excreted in the faeces. In obese patients the elimination half-life is approximately 16 days compared with 9 days in non-obese patients due to a larger volume of distribution.
The efficacy of rimonabant has been investigated in large scale international clinical trials involving over 6,800 patients. In the Phase III trials patients also followed a restrictive diet and were advised to increase their physical activity. All had either a BMI >30 kg/m2 or a BMI >27 kg/m2 with hypertension and/or dyslipidaemia. Significant mean weight reductions from baseline were observed in rimonabant treated patients compared with the placebo controls, mostly within the first nine months of treatment. Rimonabant was also shown to be effective in maintaining weight loss for up to two years. In non-diabetic patients 50.8% of those given rimonabant achieved a 5% weight reduction after one year compared with 19.7% of the placebo controls. Moreover, 27% of the rimonabant group achieved a 10% reduction in weight compared with 7.8% of the placebo controls. Similarly in diabetic patients 49.4% achieved a 5% weight reduction and 16.2% achieved a 10% reduction after one year compared with 14.5% and 2% of the placebo controls, respectively. It was also concluded that rimonabant reduced the risk of weight regain over two years.
In these studies, waist circumference was also significantly reduced by rimonabant treatment and the significant improvements in HbA1c, HDL-cholesterol and triglycerides observed compared with placebo were beyond that expected from weight loss alone.
Adult Dose: One tablet daily, in the morning, introduced with a mildly reduced calorie diet.
Child Dose: Not recommended.
Contraindications: Severe renal or hepatic impairment. Uncontrolled serious psychiatric illness. Pregnancy, lactation.
Special precautions: Mild to moderate renal or moderate hepatic impairment. Epilepsy. Recent cardiovascular event such as MI or stroke. Elderly.
Interactions: Ketoconazole, itraconazole, ritonavir, telithromycin, clarithromycin, nefazodone. Rifampicin, phenytoin, phenobarbital, carbamazepine, St John's wort. Antidepressants.
Adverse reactions: Sinusitis, upper respiratory tract infection, depression, altered mood, anxiety, irritability, nervousness, sleep disorders, insomnia, anorexia, decreased appetite, memory loss, dizziness, loss of concentration, hypoaesthesia, sciatica, flushes, GI upset, dry mouth, pruritus, hyperhidrosis, tendonitis, muscle cramp or spasm, asthenia, fatigue, influenza-like symptoms.
? Report any adverse reaction to CHM.