People who suffer from migraines and have to take a preventative medication, may have noticed a particularly beneficial side effect – weight loss. The drug topiramate, which is given to people who typically have 3 to 4 migraines a month, has amongst its very common side effects (more than 1 in 10 people) a loss in weight. And now scientists are looking more closely at this drug in an attempt to help obese patients lose weight. A study reported in the lancet by Dr. Kishore Gadde at Duke University showed that a new combination of two existing drugs: phentermine, a prescription short-term weight-loss drug, and topiramate helped obese patients lose nearly 10% of their body weight in a year.
The study involved 2,487 participants who were all either overweight or obese, with a BMI of 27 to 45. A normal BMI registers between 18.5 to 24.9. In the study, all participants were given a standard diet and exercise counselling, with half randomly assigned to take a once daily placebo or one of two doses of the combination weight-loss pills. The group that took the combination medication for a year lost an average of 19 lbs. more than those on placebo. This is a subject close to my heart as I currently take topiramate and have actually experienced weight loss for myself. I have found that by taking this drug on a regular basis, my appetite was substantially decreased to a point where I would forget to eat and skip main meals. In the two years that I have been taking topiramate I have lost over 2 stone in weight.
Phentermine is known to decrease appetite, but it is often used only for short-term weight loss, since it’s not clear how safe or effective the stimulant might be when used long term. Topiramate has only been been tested as a weight-loss drug after migraine studies showed users lost weight, but it has other side effects including memory loss, cognitive changes and some psychiatric abnormalities so it has not been a popular choice for a weight-loss treatment.
Dr Gadde therefore looked at lower doses of each of the drugs and used them in combination to help boost their ability to help obese patients. He says that “If you have a treatment with multiple mechanisms, you have a greater chance of helping people to lose weight.” Other side effects of topiramate include dry mouth, numbness or tingling in the extremities, constipation, insomnia, depression and anxiety. The only side effect I experienced, apart from weight loss was a tingling, rather like pins and needles in my hands, face and feet, but this has now disappeared. The current trial showed that the side effects disappeared after participants stopped the medication, but there may be more permanent effects to consider.
The new combination drug named Qnexa has been rejected by the FDA for approval as it has asked the company for further safety studies, especially on the risk of birth defects. Topiramate has been linked to an increased risk of cleft lip and palate deformities in babies born to women using the medication, but according to Gadde, whilst some of the volunteers in the current study did get pregnant during the trial, none had babies affected by this birth defect.
Still, a pill that could actually help obese patients to actively lose weight could really be beneficial in starting a weight loss programme that they can keep to. Many obese patients have trouble getting off a large amount of weight and feel unmotivated by small decreases in weight. This combination of pills could provide the answer to helping them shift the majority of weight and then progress to a healthy eating plan to sustain the weight loss.