Phentermine
TabletsGenerally, it is recommended by the Food and Drug Administration (FDA) that phentermine should be used short-term (usually interpreted as 'up to 12 weeks'), while following nonpharmacological approaches to weight loss such as healthy dieting and exercise. However, recommendations limiting its use for short-term treatment may be controversial. One reason given behind limiting its use to 12 weeks is drug tolerance, whereby phentermine loses its appetite-suppressing effects after the body adjusts to the drug. On the contrary, it has been shown that phentermine did not lose effectiveness in a 36-week trial. Due to the risk of insomnia, it is generally recommended that the drug be taken either before breakfast or 1-2 hours after breakfast.
Contraindications and warnings
• Patients with the following should not use Phentermine:
o An allergy to any ingredient in Phentermine or other sympathomimetics (eg, pseudoephedrine)
o Are also taking dexfenfluramine, fenfluramine, furazolidone, guanadrel, guanethidine, or have taken a monoamine oxidase inhibitor (MAOI) (eg, phenelzine) in the last 14 days
o Have severe high blood pressure, an overactive thyroid, glaucoma, heart or blood vessel disease, or severe narrowing of the blood vessels
o Are in an agitated state, or have a history of substance abuse
• Some medical conditions may interact with Phentermine, patients with the following should consult with their doctor before using phentermine: o Are also taking dexfenfluramine, fenfluramine, furazolidone, guanadrel, guanethidine, or have taken a monoamine oxidase inhibitor (MAOI) (eg, phenelzine) in the last 14 days
o Have severe high blood pressure, an overactive thyroid, glaucoma, heart or blood vessel disease, or severe narrowing of the blood vessels
o Are in an agitated state, or have a history of substance abuse
o Are pregnant, planning to become pregnant, or are breast-feeding
o Are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
o Have allergies to medicines, foods, or other substances
o Have a brain or spinal cord disorder, hardening of the arteries, high blood pressure, diabetes, or high cholesterol or lipid levels
• Some medicines may interact with Phentermine, such as the following: o Are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
o Have allergies to medicines, foods, or other substances
o Have a brain or spinal cord disorder, hardening of the arteries, high blood pressure, diabetes, or high cholesterol or lipid levels
o Dexfenfluramine, fenfluramine, furazolidone, or MAOIs (eg, phenelzine) because the risk of serious side effects, such as increasing headache, high blood pressure, slow heart rate, elevated temperature, or possibly fatal lung problems, may be increased
o Serotonin specific reuptake inhibitors (eg, fluoxetine) because the risk of their side effects may be increased by Phentermine
o Guanadrel or guanethidine because their effectiveness may be decreased by Phentermine
o Serotonin specific reuptake inhibitors (eg, fluoxetine) because the risk of their side effects may be increased by Phentermine
o Guanadrel or guanethidine because their effectiveness may be decreased by Phentermine