Drug Therapy

Main elements of obesity treatment is diet and exercise.  However, drug therapies may also be added by endocrinologists in some patients.  It should not be forgotten that there is not any chance of achievemnt for obesity patients who have not performed life style changes required and doe not follow diet and exercise programs.

For Whom and When Is the Drug Therapy Started?

  • Patients who have applied other treatment methods, but could not obtain a result,
  • Patients with BMI>30 kg/m2,
  • Patients with a BMI value over 27 kg/m2 who have metabolic conditions such as type 2 diabetes, hyperlipidemia, sleep-apnea, hypertension etc. may be eligible for these treatments.

Mechanism of action for drugs used in obesity treatment

  • Control of feeling of hunger: Phentermine- derivate drugs are used for this purpose.
  • Acceleration of metabolism: Catecholamine derivates accelerate the metabolism.  Ephedrine and caffeine are involved into this group.  They may increase basal energy rate through sympthomimetic effect.
  • Restriction of absorption:  Orlistate is the most important sample in this group.

Drugs used for treatment of obesity

Orlistat (Xenical)


Drug Therapy








Orlistat blocks an enzyme called pancreatic lipase and disrupts fat absorption from the intestines.  Because fats are not absorbed from the intestines, the patient defecates frequently as diarrhea after fatty meals.  These complaints decrease when fatty meals are avoided.  Since fat absorption is depressed, absorption of fat soluble vitamins may decrease.  The treatment must be run by an endocrinologist.  When required supports are taken during the treatment process, vitamin deficiencies do not create a vital risk.

Lorcaserin (Belviq)

This drug may cause 3.1 kg weight loss per year.  Efficiency is low.  It may cause a side effect called serotonin syndrome.  This syndrome appears with over stimulation of serotonin receptors.  Symptoms range from very mild symptoms to life threatening crises.  The patients may have palpitation, hypertension and contractions.  These may include severe contractions all over the body, epilepsy attacks, severe fever and shock.  Symptomatic and empirical treatment are applied.  Preventions to protect vital functions of the patients  are taken and organ damage by fever and contractions is tried to be prevented.

Phentermine-topiramate (Qsymia)

Phentermine is a short-acting drug with a poor efficacy solely.  Topiramate is an anti-epileptic drug which is used for epilepsy treatment.  It may create an approximate weight loss by 13 to 15%.  This drug should be used rigorously because of severe side effects such as unconsciousness, amnesia, dizziness.  Qsymia is a combined drug including Phentermine-Topiramate.  It has been approved among supportive drugs into diet and exercise by FDA in July, 2012.  Beyond mild side effects such as palpitation, dizziness, insomnia; it may cause problems such as suicidality, amnesia and memory loss.  Pregnant women are not allowed to use. It may cause congenital problems.

Phentermine (Adipex-P, Suprenza)

These drugs which include phentermine solely are not preferred much because of short term action and insufficient weight losses.


It is an anti-diabetic drug.  It reduces insulin resistance in fat patients with type 2 diabetes.  Mild weight-reducing effect is known.  Efficacy is low in obese people without diabetes.


It is GLP-1 anolog.  Even it has not been approved by FDA, there are articles reporting that it is as effective as orlistat, even more effective than orlistat with high doses like 3 mg/day.


It is a synthetic pramlintide anolog.  It has weight-reducing effect with varying rates in Type I and II diabetes.  It may be effective in treatment of obesity with higher doses than those used for type 2 diabetes.