Obesity is the mother of all the diseases. Obesity has been linked to all the nasty diseases like Diabetes, Hypertension, Heart diseases, Kidney diseases, Liver diseases, and Cancers.
However, little does a doctor offer as far as some magic pills are considered. And all those who have lost significant weight loss (without becoming sick) is because of the strong motivation and will.
So for those struggling to lose weight and reading about all the drugs here without the motivation necessary to lose weight, they might not get the results. Here are some of the key points from the guidelines on obesity by the American College of Endocrinology and the American Association of clinical endocrinologist [Ref].
This article just focuses on some of the approved Prescription weight loss pills.
However, "Prescription Weight loss pills" is the third line of treatment after a low-calorie diet and aerobic exercise.
(How to lose weight fast without medicines and pills [Ref]) This is also the reason why patients do not lose weight despite being on weight loss pills.
Patients do not want to quit eating and stay sedentary and LOSE WEIGHT!
So, let us come to the first question...
Should weight loss pills be used alone or as an adjunct to lifestyle therapy?
Recommendation (Grade A, BEL 1): weight loss pills should never be used alone.
They should only be used as an adjunct to lifestyle therapy [Ref].
Does the addition of weight loss pills to lifestyle therapy result in greater weight loss and helps in weight-loss maintenance?
The addition of weight-loss pills produces greater weight loss and weight-loss maintenance compared to lifestyle therapy alone.
Furthermore, a combination of pharmacotherapy and lifestyle therapy also helps in the treatment of weight-related complications (Grade A, BEL 1)
For how long should drug therapy be used?
Drug therapy should be used for a longer duration in all patients when the benefits of treatment outweigh the risks. (Grade A, BEL 1).
Short-term pharmacotherapy for 3 to 6 months has not been demonstrated to produce long-term health benefits. (Grade B, BEL 1).
A brief overview of the prescription weight loss pills
This drug is available over the counter by the trade name of XENICAL internationally and ORSLIM, ORLIS, ORLIFIT, and many others in Pakistan.
How does it work?
It inhibits the breakdown of ingested fats in the gut, making them nonabsorbable.
Thus people with a diet containing mostly fats are more to benefit from this drug.
How should this drug be taken?
Orlistat should be taken with the first bolus of a meal. It may be initiated with the major meal of the day and then increased to twice or thrice daily.
How effective is Orlistat?
It can cause a weight loss of 5 to 10%. Furthermore, it has been found to reduce blood pressure and reduce the incidence of diabetes by 37%.
What are the side effects of the drug?
It can cause gastrointestinal side effects like diarrhea, flatulence, oily evacuation, excessive gases, and deficiency of fat-soluble vitamins.
Thus, patients are advised to take their vitamin pills at least 2 hours prior to orlistat
It is an injectable medicine and very costly (average monthly cost is around 40000 PKR)
How does it work?
Liraglutide is an incretin hormone that suppresses satiety, delays gastric emptying (the patient feels a full stomach after taking a little of his diet) and has antidiabetic properties like glucose-dependent insulin secretion.
How should liraglutide be administered?
It should be injected once daily subcutaneously (into the skin) just like the insulin.
How effective is Liraglutide?
It caused a 5% weight loss in 63% of the studied individuals compared to 27.1% and 10% weight loss in 33.1% of the studied individuals compared to 10.6%.
Furthermore, it is also used to treat diabetes Mellitus type 2.
What are the side effects of Liraglutide?
It may cause gastrointestinal side effects like nausea, vomiting, abdominal fullness, pancreatitis, and has been associated with thyroid cancers in animal studies.
It is a serotonin agonist that reduces appetite.
How does it work?
Lorcaserin is a selective serotonin receptor agonist that suppresses the satiety center in the brain resulting in weight loss.
The non-selective serotonin agonists like fenfluramine and dexfenfluramine also suppress the satiety centers but are more toxic especially to the heart valves.
How should Lorcaserin be taken?
Lorcaserin should be advised in a dose of 10 mg twice daily with or without food.
How effective is Lorcaserin?
After taking lorcaserin for a mean duration of one year, lorcaserin resulted in a 5% weight loss by 47% compared to 25% in the placebo group.
A weight loss of 10% was seen in 22.6% of the patients in the lorcaserin group compared to 9.7% in the placebo group.
What are the side effects of Lorcaserin?
Common side effects of the drug include Hypoglycemia (low blood sugars especially in diabetic patients), headache, backache, flu, respiratory tract infections, and lymphopenia (low lymphocyte count). Pregnant patients should not take lorcaserin.
Phentermine/ Topiramate ER (Qsymia):
The combination of phentermine and topiramate has been approved for the treatment of obesity.
How does it work?
The primary mechanism of the combination of the drugs is to suppress appetite (and activate metabolism).
How should the pill be taken?
The combination pill is available in two strengths (3.75/23 mg and 7.5/46 mg).
It should be taken without regard to meals preferably in the morning as it may cause insomnia when taken in the evenings).
How effective is this drug?
It caused 8 to 10 kg of weight loss compared to 1.4 kg in the placebo group after one year of therapy.
It was effective in maintaining weight in the second year but was less effective in further weight loss.
What are the side effects of this drug?
It is contraindicated in patients with overactive thyroid, pregnancy, glaucoma, heart disease, uncontrolled hypertension and should be avoided within 14 days of taking Monoamine oxidase inhibitors.
It may cause an increase in blood pressure, palpitations, restlessness, insomnia, constipation, and paraesthesias.
Naltrexone ER/ Bupropion ER (Contrave):
Bupropion is approved for the treatment of depression and smoking cessation.
Naltrexone is an opioid receptor antagonist used to treat patients with alcohol and opioid dependence.
How does it work?
This drug causes anorexia and is thus an appetite suppressant.
How Should the drug be taken?
It may be taken without regard to meals, however, administration after meals may alleviate some of the gastrointestinal symptoms.
How effective is this combination?
It caused a weight loss of 5 to 6% compared to the placebo (1.3%) after one year of treatment.
What are the side effects of Naltrexone/ Bupropion?
The most common side effects of this combination of drugs noted were nausea, vomiting, constipation, headache, dizziness, and insomnia.
It may also increase blood pressure, increase suicidal ideation, and lowers the seizures threshold.
What are my thoughts?
The above five prescription weight loss pills are the only medicines approved by the American College of Endocrinology and the American Association of Clinical Endocrinologists for the treatment of obesity.
If you notice all these drugs can reduce weight by 5 to 12 % which may not be what the patient desires.
I do not prescribe these weight loss pills to any of my patients and would not recommend any of these therapies to obese patients except in the following situations:
If an obese patient is prescribed an antidepressant, I would prefer bupropion.
Bupropion may also be helpful in obese patients who wish to quit smoking.
Obese patients with migraine headaches may benefit from topiramate.
Diabetic patients who are obese may be advised liraglutide.
Wegovy is a high dose injectable once-weekly Semaglutide that has been approved by the FDA for the treatment of obesity.
It is indicated for diabetes in lower weekly injectable dose as Ozempic and oral daily tablets as Rybelsus.
It is from the same class of drugs as Liraglutide (Saxenda). It is a GLP-1 analog and has been associated with a weight loss of up to 16% of body weight.
Among all the weight loss drugs, it is considered the most potent weight loss drug until now.
Grade of recommendations are based on the review of clinical evidence
Grade A: Strong recommendation
Grade B: Intermediate
Grade C: Weak
Grade D: Based on expert opinion
BEL (Best level evidence) - Based on the evidence of scientific substantiation:
BEL 1: Strong evidence
BEL 2: Intermediate evidence