Anti-Obesity Medication

We often recommend anti-obesity medicines for overweight and obese patients because their adiposity is nearly always a chronic relapsing disease. Any increase in adipose or fat tissue beyond 25% of total weight in women and 18% in men also increases the risk of developing or aggravating a long list of obesity-related diseases including diabetes, cardiovascular diseases, sleep apnea, arthritis, fatty liver, and breast, uterine, colorectal, pancreatic, hepatic, renal, and esophageal cancer.

Obviously weight loss is important but weight successful maintenance is even more critical for lasting health benefits, which is why we treat our overweight and obese patients with aggressive medical therapy. Thus there is a marked difference between our treatment methods for the overweight and the methods of the commercial weight loss companies.

The commercial weight loss programs, particularly the ones where no physician ever sees the patient, omit a crucial component in their weight loss programs – the medical component and the anti-obesity medicines. Regrettably many medical programs also either omit or restrict the use of anti-obesity medicines.

Sometimes we are asked why we recommend including prescription anti-obesity medicines along with diet, exercise and improvements in eating behaviors. Anti-obesity drugs can:

  • Enhance weight loss.
  • Improve success with weight maintenance.

  • Arrest or slow progressive weight gain.

  • Make it easier to stick to a diet.

  • Reduce or eliminate food cravings.

  • Counteract increased eating induced by other medicines.

  • Improve eating restraint.

  • Improve eating behavior.

  • Increase energy level.

  • Increase ability to concentrate


What are the risks? The truth is being overweight, carrying excess fat, is very risky for your health – far, far more risky than taking any of the anti-obesity medicines. Ask yourself ‘has the person who told me an anti-obesity drug is unsafe offered any real help to deal with my weight?’ If no, you should consider coming to see us for a free interview with one of our practitioners. Ask us what are my risks and we can give you truthful answers specific to your health.

What are the medicines and what might I expect?

Comparative Weight Loss Results with Drugs for Treating Obesity

These tables are meant to provide physicians with comparisons of average weight loss results they might expect using the various drugs in clinical practice, and for some drugs the extent to which Obesity Treatment Specialists (OTS) are prescribing them. The tables are not meant to be an authoritative compilation of all data on these drugs but are from selected studies using data from ‘completer’ or ‘responder’ patients. Results were estimated from graphs in cases where authors did not provide numerical tables. Benefits of drug treatment other than weight loss are not included. Physicians should be aware that in some jurisdictions there are legal restrictions on the manner in which some of these drugs are prescribed.

Drugs approved for weight loss that have been used clinically both for weight loss and for weight loss maintenance:

Results 1 year
Mean Dose
Used by % OTS*
In __% of patients*
Orlistat (Xenical)
-3.9 Kg
2 yr. – 2.3Kg
360 mg/d
43% (43%)
8% (6%)
Lorcaserin (Belviq)
-7.7 Kg;   -7.9%
20 mg/d
Phen/Topira (Qsymia)
2 yr -11.5%
15/92 mg/d
-17.3 Kg; -17.6%
5 yr. -11.4%
41 mg/d
97% (99%)
49% (46%)
Diethylpropion (Tenuate)
-10.1 Kg; -10.6%
100 mg/d
64% 63%)
15% (16%)
– 3.6 Kg (12 wks.)
105 mg/d
60% (60%)
18% (18%)
Le Riche6**

Drugs approved for other indications used as weight loss and maintenance drugs:

Results 1 year
Mean Dose
Used by % OTS*
In __% of patients*
-16.3 Kg; -16.4%
96 mg/d
50% (63%)
-4.0 Kg
400 mg
3%   (2%)
5%   (4%)
Liragultide (Victoza)
-7.8 Kg
2 yr. -5.3 Kg
3 mg/d

Drugs approved for other indications that have been used as adjuncts in treating obesity:

Results 24 weeks
Used by % OTS*
In __% of patients*
– 4.8 Kg
– 8.0 Kg
21% (20%)
8% (11%)
– 4.4 Kg (16 wks.)
– 2.9 Kg
-2.8 Kg (1 yr)
35% (24%)
17% (42%)

Abbreviations: OTS = Obesity Treatment Specialists, Phen/Topira = Phentermine/Topiramate

Notes:* Data from 2008 and (2012 unpublished) surveys by American Society of Bariatric Physicians.11 ‘In __% of patients’ averages of survey respondents’ answers to the question ‘in what % of your patients did you prescribe this drug?’

** A retrospective report with a small number of patients. There is no data in the literature with patient results beyond 12 weeks.


1. Astrup A, Carraro R, Finer N, et al. Safety, tolerability and sustained weight loss over 2 years with the once-daily human GLP-1 analog, liraglutide. Int J Obes (Lond). 2013;37:322.

2. Fidler MC, Sanchez M, Raether B, et al. A one-year randomized trial of lorcaserin for weight loss in obese and overweight adults: the BLOSSOM trial. J Clin Endocrinol Metab. 2011;96:3067-77.

3. Garvey WT. Phentermine and topiramate extended-release : a new treatment for obesity and its role in a complications-centric approach to obesity medical management. Expert Opin Drug Saf. 2013.

4. Hendricks EJ, Greenway FL, Westman EC, et al. Blood pressure and heart rate effects, weight loss and maintenance during long-term phentermine pharmacotherapy for obesity. Obesity (Silver Spring). 2011;19:2351-60.

5. Cercato C, Roizenblatt VA, Leanca CC, et al. A randomized double-blind placebo-controlled study of the long-term efficacy and safety of diethylpropion in the treatment of obese subjects. Int J Obes (Lond). 2009;33:857-65.

6. Le Riche WH, Van Belle G. Study of phendimetrazine bitartrate as an appetite suppressant in relation to dosage, weight loss and side effects. Can Med Assoc J. 1962;87:29-31.

7. Astrup A, Caterson I, Zelissen P, et al. Topiramate: long-term maintenance of weight loss induced by a low-calorie diet in obese subjects. Obes Res. 2004;12:1658-69.

8. Gadde KM, Kopping MF, Wagner HR, et al. Zonisamide for weight reduction in obese adults: a 1-year randomized controlled trial. Arch Intern Med. 2012;172:1557-64.

9. Astrup A, Carraro R, Finer N, et al. Safety, tolerability and sustained weight loss over 2 years with the once-daily human GLP-1 analog, liraglutide. Int J Obes (Lond). 2012;36:843-54.

10. Bray GA. Why do we need drugs to treat the patient with obesity? Obesity. 2013;21:893-9.

11. Hendricks EJ, Rothman RB, Greenway FL. How physician obesity specialists use drugs to treat obesity. Obesity (Silver Spring). 2009;17:1730-5.

Ed J. Hendricks, M.D.
May 3, 2014

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