From the FDA Drug Label
Phendimetrazine tartrate is indicated in the management of exogenous obesity as a short term adjunct (a few weeks) in a regimen of weight reduction based on caloric restriction in patients with an initial body mass index (BMI) of 30 kg/m 2 or higher who have not responded to appropriate weight reducing regimen (diet and/or exercise) alone To limit unwarranted exposure and risks, treatment with phendimetrazine tartrate should be continued only if the patient has satisfactory weight loss within the first 4 weeks of treatment (i.e., weight loss of at least 4 pounds, or as determined by the physician and patient) Phendimetrazine tartrate is not recommended in patients with known heart murmur or valvular heart disease Baseline cardiac evaluation should be considered to detect pre-existing valvular heart diseases or pulmonary hypertension prior to initiation of phendimetrazine treatment Use of phendimetrazine tartrate within 14 days following the administration of monoamine oxidase inhibitors may result in a hypertensive crisis
The recommended dosing for phendimetrazine therapy for weight loss is not explicitly stated in the provided drug labels. However, the following key points should be considered when initiating phendimetrazine therapy:
- Indications: Phendimetrazine tartrate is indicated for the management of exogenous obesity as a short-term adjunct in a regimen of weight reduction based on caloric restriction in patients with an initial body mass index (BMI) of 30 kg/m 2 or higher who have not responded to appropriate weight reducing regimen (diet and/or exercise) alone 1.
- Contraindications: Phendimetrazine tartrate is not recommended in patients with known heart murmur or valvular heart disease, and in patients who used any anorectic agents within the prior year 1.
- Patient Education: Patients should be cautioned about the potential risks of phendimetrazine therapy, including the development of pulmonary hypertension and valvular heart disease, and the importance of regular monitoring and follow-up appointments 1.
- Treatment Duration: Treatment with phendimetrazine tartrate should be continued only if the patient has satisfactory weight loss within the first 4 weeks of treatment (i.e., weight loss of at least 4 pounds, or as determined by the physician and patient) 1.
- Important Warnings:
- Phendimetrazine tartrate should not be used in combination with other anorectic agents, including prescribed drugs, over-the-counter preparations, and herbal products 1.
- The use of phendimetrazine tartrate within 14 days following the administration of monoamine oxidase inhibitors may result in a hypertensive crisis 1.
From the Research
Phendimetrazine therapy for weight loss should be initiated with a dose of 35 mg taken orally 2-3 times daily, administered one hour before meals, as part of a comprehensive weight management program that includes dietary changes, exercise, and behavioral modification, with careful consideration of potential side effects and contraindications, as supported by the most recent study 2. When initiating phendimetrazine therapy, it is essential to educate patients about the potential for abuse and dependence, as well as the common side effects, which include increased heart rate, elevated blood pressure, insomnia, dry mouth, and constipation.
- Patients should be advised to avoid taking the medication in the evening to prevent sleep disturbances and should not abruptly discontinue use after prolonged therapy to prevent withdrawal symptoms.
- Phendimetrazine works by stimulating the central nervous system to increase norepinephrine levels, which helps suppress appetite and increase energy expenditure.
- The medication is contraindicated in patients with cardiovascular disease, hypertension, hyperthyroidism, glaucoma, history of drug abuse, or during pregnancy.
- Regular monitoring of vital signs and weight loss progress is essential throughout treatment, as shown in a study that evaluated the 3- and 6-month efficacy and safety of phentermine in obese Mexican patients 2. Key points to consider when prescribing phendimetrazine include:
- Starting dose: 35 mg taken orally 2-3 times daily, administered one hour before meals
- Alternative formulation: extended-release formulation of 105 mg can be taken once daily in the morning
- Comprehensive weight management program: includes dietary changes, exercise, and behavioral modification
- Potential side effects: increased heart rate, elevated blood pressure, insomnia, dry mouth, and constipation
- Contraindications: cardiovascular disease, hypertension, hyperthyroidism, glaucoma, history of drug abuse, or during pregnancy
- Regular monitoring: vital signs and weight loss progress throughout treatment, with consideration of the findings from the study on the efficacy and safety of phentermine in a Mexican obese population 2.