Medical therapies v placebo for obesity*

DrugNumber of placebo controlled RCTsFollow upWeight loss (kg) (95% CI or range)Commonly reported side effects
*RCT  =  randomised controlled trial; CI defined in glossary. A random effects model was used.
Sibutramine1216–24 weeks−3.4 to −6.0Increased heart rate (4 beats/minute)
544–54 weeks−4.5 (−5.3 to −3.6)
Phentermine62–24 weeks−3.6 (−6.0 to –0.6)Palpitations, tachycardia, increased blood pressure, central nervous system and gastrointestinal effects
Diethylpropion96–52 weeks−3.0 (−11.5 to 1.6)Central nervous system effects, dizziness, headache, insomnia, restlessness, increased blood pressure, palpitations, tachycardia, gastrointestinal effects, rash
Orlistat126 months−2.6 (−3.5 to –1.7)Diarrhoea, flatulence, bloating, abdominal pain, dyspepsia
2212 months−2.9 (−3.5 to –2.3)
Fluoxetine76 months−0.9 to –9.1Nervousness, sweating, tremors, nausea, vomiting, fatigue, asthenia, hypersomnia, somnolence, insomnia, diarrhoea
612 months−14.5 to 0.4
Bupropion36–12 months−2.8 (−4.5 to –1.1)Dry mouth
Topiramate (percentage weight loss)66 months−6.5% (−8.3 to –4.8)Paraesthesia, taste perversion, central nervous system effects, constipation, dry mouth, upper abdominal symptoms, fatigue