Phentermine is a prescription stimulant medication used for short-term weight management. It acts as an appetite suppressant and is available only through a healthcare provider’s prescription. Phentermine is classified as a Schedule IV controlled substance due to its potential for misuse and dependence.
What Phentermine Is Used For
Phentermine is prescribed as an adjunct to a weight-loss regimen that includes dietary changes, increased physical activity, and behavioral modifications. It is indicated for individuals with exogenous obesity, defined by a body mass index (BMI) of 30 kg/m² or greater. It may also be prescribed for those with a BMI of 27 kg/m² or greater who have co-existing weight-related risk factors, such as controlled hypertension, diabetes, or hyperlipidemia.
The medication is used for a limited duration, usually a few weeks, to help initiate weight loss. While significant weight loss often occurs in the initial weeks, some studies suggest continued, albeit slower, loss over several months. The goal is to provide a temporary aid that supports patients in establishing healthier lifestyle habits for sustained weight management.
Standard Dosing of Phentermine
Phentermine is prescribed in specific dosages, with 15 mg, 30 mg, or 37.5 mg being typical daily amounts. These doses are taken once daily in the morning, either before or 1 to 2 hours after breakfast. For some patients, a lower dose, such as 18.75 mg (half of a 37.5 mg tablet), may be sufficient, or it might be divided into two daily doses.
A daily dose of 75 mg of phentermine is much higher than the recommended maximum daily dose of 37.5 mg. Taking 75 mg is not medically advised and is unsafe, potentially leading to an overdose. Exceeding the standard maximum dose increases the risk of severe adverse effects without providing a proportional increase in efficacy. Dosages are individualized by a healthcare professional to achieve an adequate response with the lowest effective dose, considering the patient’s specific needs and tolerance.
Risks and Side Effects of Phentermine
Phentermine can cause various side effects, which may be more pronounced or severe at higher doses like 75 mg. Common side effects include dry mouth, an unpleasant taste, constipation, diarrhea, headache, dizziness, restlessness, and insomnia. These milder effects are manageable but can still be uncomfortable.
More serious side effects are a concern, especially with excessive doses. These can include increased blood pressure, heart palpitations, and an elevated heart rate. Rare reports exist of serious cardiovascular events such as stroke, angina, and heart failure. Other severe effects can involve tremors, confusion, psychotic episodes, hallucinations, and an irregular heartbeat. The potential for dependence and abuse also exists, particularly with prolonged use or higher dosages.
When to Consult a Healthcare Professional
Immediate consultation with a doctor or emergency services is advised if someone has taken 75 mg of phentermine or is experiencing severe side effects. Symptoms such as severe headache, blurred vision, chest pain, shortness of breath, pounding heartbeats, or swelling in the ankles or feet warrant immediate medical attention. These signs could indicate a serious reaction or overdose.
Phentermine should only be taken under medical supervision, and patients should never adjust their dosage without consulting their prescribing physician. Discussing any concerns about the medication’s dosage, its effectiveness, or any experienced side effects with a healthcare provider is important. It is also important to inform your doctor about all other medications, supplements, and herbal products being taken to avoid potential drug interactions.