From the Guidelines
The recommended dosage range for topiramate (Topamax) in weight loss treatment is 3.75 to 15 mg per day, in combination with phentermine, as part of a phentermine/topiramate extended-release formulation. This dosage range is based on the FDA-approved combination of phentermine and topiramate for the treatment of obesity, as studied in the EQUIP, CONQUER, and SEQUEL trials 1. The typical starting dose is 3.75 mg daily, with gradual increases to 7.5 mg, 11.25 mg, and up to 15 mg daily, if well-tolerated and additional weight loss is desired.
Key Considerations
- The exact mechanism of topiramate in weight loss is unknown, but it is believed to decrease caloric intake by reducing appetite and altering taste preferences 1.
- Phentermine/topiramate extended-release is a Schedule IV compound, indicating potential for abuse and dependence.
- Patients should be monitored for side effects, such as tingling sensations, dizziness, and difficulty concentrating, and the dose should be adjusted as needed.
Administration and Monitoring
- Topiramate should be taken orally, with or without food, but consistency is recommended.
- Patients should drink plenty of water while on this medication to reduce the risk of kidney stones.
- Regular follow-ups are essential to assess the effectiveness and safety of the treatment, as well as to monitor for potential side effects.
Evidence-Based Recommendation
The recommendation is based on the highest quality study available, which is the 2017 study on the practical use of pharmacotherapy for obesity, published in the journal Gastroenterology 1. This study provides the most recent and relevant evidence on the use of topiramate for weight loss, and its findings support the recommended dosage range of 3.75 to 15 mg per day, in combination with phentermine.
From the Research
Dosage Range for Topiramate in Weight Loss Treatment
The appropriate dosage range for topiramate (Topamax) in weight loss treatment is as follows:
- The study 2 mentions that the controlled-release formulation of phentermine and topiramate at low, medium, and full doses, with the full dose containing 15 mg of phentermine hydrochloride and 92 mg of topiramate, promotes weight reduction.
- The study 3 recommends starting therapy with topiramate at a daily dosage of 25 mg, increasing by 25 mg every week up to 200-400 mg/day, but not exceeding 1000 mg/day.
- The study 4 used once-daily phentermine 7·5 mg plus topiramate 46·0 mg, or once-daily phentermine 15·0 mg plus topiramate 92·0 mg, and found that both combinations promoted weight reduction.
- The study 5 found that patients treated with topiramate lost an average of 5.34 kg of additional weight as compared with placebo, and that treatment duration and dosage were associated with the efficacy of topiramate treatment.
- The study 6 evaluated the efficacy and safety of topiramate at doses of 64,96,192, or 384 mg daily, and found that topiramate produced significantly greater weight loss than placebo at all doses.
Key Findings
- Topiramate dosages ranging from 46 mg to 384 mg per day have been used in weight loss studies 2, 4, 6.
- The most effective dosage range for topiramate in weight loss treatment appears to be between 96 mg and 200 mg per day 5, 6.
- Topiramate has been shown to be effective in promoting weight loss when used in combination with phentermine 2, 4 or as a monotherapy 5, 6.