Which drug is listed as the better choice for obesity treatment?

• A. Orlistat
• B. Lorcaserin (serotonin receptor agonist)
• C. Topiramate
• D. Phentermine/topiramate (Qsymia)

Answer: (B)

In obesity pharmacotherapy, choosing a medication comes down to how much weight it helps you lose and how safe it is for long-term use. Among the options listed, the combination of a stimulant (phentermine) with topiramate extended-release tends to produce the largest average weight loss in clinical trials, often around 8–10% of body weight over about a year, and it can improve several metabolic risk factors. That level of efficacy usually makes it the preferred option when there are no contraindications and a clinician can monitor for side effects such as increased heart rate, blood pressure, mood or cognitive changes, and potential teratogenicity, with pregnancy being a major contraindication.

Orlistat works by blocking fat absorption and yields modest weight loss with common gastrointestinal side effects and potential vitamin absorption issues. Topiramate alone also promotes weight loss but carries cognitive and paresthesia effects and other tolerability concerns. Lorcaserin, which was designed to suppress appetite, was associated with cancer-risk signals in studies and has been withdrawn in many places, so it is no longer considered a top choice in current practice.

So, the best option among these, based on overall efficacy and safety profile, is the phentermine/topiramate combination.