FDA-approved
Phentermine-topiramate
A two-drug pill that reduces appetite and increases fullness.
KEY EVIDENCE
CONQUER (Lancet 2011)
VIDEO LESSON
How it's taken
• Once daily in the morning, starting at a low dose and increasing
Side effects at a glance
• Tingling, dry mouth, constipation
• Insomnia and changes in taste
Monitoring
Heart rate, mood and, for women who can become pregnant, monthly pregnancy tests.
AT A GLANCE
Type
Medication
Brand names
Qsymia
Status
FDA-approved
Reviewed by
Farhan Tahir, MD
Is this treatment right for you?
Prescription medicines and procedures need individual medical advice. Dr. Tahir’s team offers consults through Youthful Medicine.
How it works
Phentermine reduces appetite through norepinephrine signaling; topiramate adds satiety effects through GABA and glutamate pathways. Taken once daily as an extended-release capsule.
What the evidence shows
In CONQUER, the top dose produced a mean 9.8% weight loss at 56 weeks versus 1.2% on placebo.
Side effects & cautions
Causes birth defects: requires reliable contraception and pregnancy testing under a safety program. Can raise heart rate and cause insomnia, tingling, dry mouth and cognitive slowing. Not for glaucoma, hyperthyroidism or with MAO inhibitors.
PRIMARY SOURCE
Gadde KM, et al. Effects of low-dose, controlled-release phentermine plus topiramate on weight and associated comorbidities (CONQUER). Lancet. 2011
TYPICAL RESULT IN TRIALS
Around 8% to 10% average weight loss at the top dose.
PHYSICIAN FIRST
Is this right for you?
Prescription treatments need a review of your history, labs and other medicines. Never start or stop one on your own.