Medicines have a certain influence on obesity treatment. Medications for weight loss are restricted in quantity and efficiency. Nevertheless, drugs for weight loss can help patients to change their lifestyle, to achieve clinically significant and effective reduction of symptoms, risk factors and to improve the life quality. Physician should understand the benefits and risks, associated with the use of these medications to choose the right one.

Researches of the drugs action mainly affect small period of time. Study results of prolonged efficiency are not established. Most part of researches covers the period of 1-2 years of obesity treatment. Use of all drugs was stopped after this period, since obesity is incurable illness, it returns just like diabetes after the discontinuation of insulin therapy.

In randomized trials of drugs, approved by the FDA in combination with the changes of lifestyle was demonstrated that body weight was reduced by 3-5% by means of medicines for weight loss.

  • Reduction in risk factors of cardiovascular diseases is mainly associated with the reduction of fat deposits.
  • Criteria for pharmacological therapy in combination with the lifestyle changes for weight loss and its prevention:
    • BMI>30;
    • BMI>27 in the presence of obesity-related diseases.

Phentermine and Diethylpropion

  • Adrenergic agents increase norepinephrine release in the certain brain parts that leads to the reduced food consumption. However, there are restricted data about efficiency and safety of the drugs.
  • It is necessary carefully to supervise patients with high blood pressure or patients who get antihypertensive therapy.
  • Randomized studies have shown that body mass reduced by 3-4% compared to placebo. (The medications are already unavailable in Europe).
  • Adrenergic agents may be taken periodically, restricted data indicate that stimulants may be effective during 10 years.
  • There is a potential (although low) risk of drug dependence (medicines are classified by Drug Enforcement Agency in the USA as substances, controlled under the scheme IV).


  • Sibutramine is a serotonin–norepinephrine reuptake inhibitor which suppresses an appetite. Sibutramine in combination with lifestyle changes showed a greater weight loss in the period up to 12 months (Sibutramine in combination with lifestyle changes - 12.1kg; Sibutramine monotherapy – 5.0kg; lifestyle changes only – 6.7kg).
  • Sibutramine drug helps to reduce body weight but does not affect blood pressure.
  • Randomized studies have demonstrated that Sibutramine drug contributes to weight loss by 5% more than placebo (only short-term effect of the drug was studied; Sibutramine use more than 18 months is prohibited).
  • Sibutramine is moderately effective in weight loss and has inconsistent data on the risk of cardiovascular disease, as well as profiles of various side effects.
  • Most common Sibutramine side effects include: increased blood pressure and tachycardia (due to adrenergic properties of the drug).
  • Patients who were the most physically active and those who achieved the most significant weight loss are likely to be the most successful to maintain the body weight.


  • The drug is a gastrointestinal lipase inhibitor and contributes to 30% reduction of the fat absorption in the intestinal lumen.
  • Orlistat use or diet therapy reduces body mass and blood pressure level in patients with essential hypertension.
  • Studies have proven Orlistat efficiency in weight loss by 2% greater than placebo in the period of 4 up to 24 months of use).
  • Orlistat data about the risk of cardiovascular diseases and profiles of different side effects are not reliably established.
  • Main Orlistat side effects (usually short-term) include: oily discharges from the rectum, flatulence, rectal urgency.
  • One of the clinical trials of Orlistat effect in combination with lifestyle change has shown that body mass reduced by 3% more than in lifestyle change without the drug use.
  • Pharmacological effect of Orlistat depends on the fat amount in the diet. Obese patients taking Orlistat should use low-calorie diet.
  • In the U.S. Orlistat is available in over-the-counter (OTC) form in low doses (60mg three times daily).


  • The drug is a selective cannabinoid receptor type 1 (CB1) antagonist. Cannabinoid system plays a great role in regulation of food intake, energy balance and body mass.
  • This is a new drug, so it is necessary more qualitative studies of the drug with prolonged period of dynamic follow-up after treatment, then certain recommendations can be made.
  • Rimonabant drug is not approved by the FDA due to potential side effects (such as, depression; suicidal thoughts; anxiety; diarrhea and nausea).
  • Rimonabant drug is approved in most European countries, as well as in Mexico and Argentina for obesity treatment. However Rimonabant drug is contraindicated in patients with severe depression and (or) patients, who are getting antidepressant therapy.
  • Rimonabant pills are not recommended for patients with psychiatric disorders.
  • Duration of Rimonabant use is not more than 2 years.
  • Rimonabant use provides a moderate weight loss of approximately 5% during a year. Nevertheless, even a moderate weight loss may be effective when treating obesity.

Other weight loss drugs

  • Metformin (for obese patients with diabetes; for obese patients, receiving antipsychotic drugs, leading to insulin resistance; as well as for obese women with polycystic ovary syndrome).
  • Topiramate (for patients with obesity and bipolar disorders).
  • Venlafaxine (night eating syndrome).
  • Fluoxetine (for patients with bulimia, obesity, night eating syndrome, and sleep apnea).
  • Bupropion (for obese patients with smoking addiction).