Early safety test of lorcaserin, phentermine conducted

the Clinical Advisor take:

A study of the combination of lorcaserin (Belviq) and phentermine found no major differences in serotonergic adverse effects and possible increased weight loss, according to a report published in MedPage Today.

Lead researcher Steven Smith, MD, of Florida Hospital in Orlando, and colleagues found that patients lost a greater proportion of their body weight over a 12-week period with a combination of the two drugs compared with lorcaserin alone.

The phase II study randomized 238 overweight and obese patients to one of three groups: lorcaserin alone (10 mg twice a day) or lorcaserin plus phentermine (15 mg), either once or twice daily. Each patient received standard weight-loss counseling during the 12-week trial.

The researchers looked primarily at the proportion of patients reporting at least one of nine common potential serotonergic adverse events: headache, dizziness, nausea, fatigue, dry mouth, diarrhea, vomiting, insomnia, or anxiety.

The researchers found that this primary endpoint occurred in a similar proportion across all three groups, with the most common adverse effects being dry mouth, headache, constipation, fatigue, and dizziness. However, more patients in the twice-daily phentermine group discontinued due to adverse effects.  The addition of phentermine also diminished improvements in blood pressure and heart rate seen with only lorcaserin.

Adam Tsai, MD, of Kaiser Permanente Colorado in Denver and chair of The Obesity Society's public affairs committee, said the question will be whether the weight-loss benefits of the combination will outweigh the increases in these cardiovascular risk markers.