Qsymia has been approved as an addition to a reduced calorie diet and increase in exercise for chronic weight management in patients with an initial BMI of 30 (obese) or 27 (overweight) with at least one medical condition such as high blood pressure, diabetes, or high cholesterol.
Qsymia was originally presented as Qnexa for approval but it was felt the name was too close to other drugs on the market. Qsymia is manufactured by Vivus and is a combination of phentermine and topiramate. This combination being used for weight loss is not a new concept. Phentermine is the most widely used appetite suppressant in the US. Topiramate – brand name Topamax- is used for seizure disorders and migraine prevention. As Topamax was studied for these original uses, it was noted that weight loss was a side effect. Bariatricians (medical weight loss specialists) have been using topiramate off label successfully for weight management for several years and noticed that it decreases appetite, food cravings, and binge eating. They have also been using doses that are higher than the combination found in Qsymia. The exact mechanism for how topiramate helps with weight loss is still unclear.
Qsymia will only be available from specific mail order pharmacies and the health care provider must be registered to provide prescriptions for Qsymia. So let’s break down the most important parts of the 17 page Full Prescribing Information sheet …..
1. General dosing – patient will begin the lowest dose and it is given once daily in the morning so that it is less likely to cause insomnia. The dose is increased after 2 weeks. The dose may be further increased at intervals of 12 weeks if certain weight loss is not achieved. The highest dose of Qsymia should not be stopped suddenly due to the possibility of precipitating a seizure. So here is a potential problem I see – I have plenty of patients that run out of appetite suppressants when they can’t get to the clinic for their monthly follow-up – they go on vacation, a parent or child gets sick, or they get tied up at work. What is going to happen in this situation?
2. Pregnancy – topiramate can cause fetal harm. It increases the risk of oral clepts so it should not be taken by women who are pregnant or trying to become pregnant. And to take Qsymia, you must actively prevent pregnancy. This means a pregnancy test before starting treatment and monthly during treatment. You must also commit to birth control use while taking it, very similar to taking Accutane. The interesting thing is that this has never been required when using topiramate for other indications. I don’t think this is a bad idea as I have had many women “accidentally” get pregnant while losing weight. Weight loss increases fertility, lowers insulin resistance, and increases libido which means more babies.
3. Major side effects/ risks include:
- Acute Closed Angle Glaucoma- sudden onset of decreased vision and eye pain. Typically occurs the first month of treatment and needs immediate treatment to prevent permanent loss of vision.
- Increased heart rate
- Suicidal behavior – increase of 1 in every 530 patients treated
- Mood and Sleep Disorders – resolve spontaneously once medication was stopped
- Cognitive Impairment – loss of attention, concentration, difficulty with memory, speech problems, and word-finding problems. A patient once joked with me that she decided being skinny probably wasn’t worth forgetting her kid’s name. She was only half joking and we decided to stop her Topamax.
- Kidney Stones – topiramate promotes kidney stone formation
- Low potassium which can worsen when used with diuretics
- Elevation in creatinine which could mean a decline in kidney function
- Hypoglycemia in diabetics on diabetic medication – kind of a no brainer- if you are eating less and losing weight, glucose levels should be improving. Glucose needs to be monitored by patients during treatment and medications adjusted as needed.
- Low blood pressure in patients with hypertension treated with medication – again as patients are losing weight, blood pressure should go down and medication will need to be adjusted to prevent the blood pressure from going too low.
- Caution should be used if given to patients with kidney or liver problems.
- Decreased sweating that could lead to overheating
- Paresthesias – tingling in the hands
- Dizziness, insomnia, constipation, and dry mouth
Qsymia will be an additional tool to use for weight management and the combination has been used successfully by doctors for weight loss for several years. However, it has significant risks and side effects and using it should be a joint decision with your medical professional. I also advise patients see a physician that has experience with the use of topiramate – this should not be a prescription handed out after a one minute conversation about needing to lose a few pounds with your physician. It should be used appropriately as part of a program to change lifestyle to achieve permanent weight loss.