Phentermine is the generic name for an obesity management drug. Brand names include Adipex-P, Fastin, Ionamin, Obenix, Obephen, Oby-Cap, Oby-Trim, Panshape M, Phentercot, Phentride, Pro-Fast HS, Pro-Fast SA, Pro-Fast SR, Teramine, and Zantryl. Phentermine is used as both short-term and long-term medicine to treat obesity, usually accompanied by diet and behavior modification. It will suppress appetite by affecting neurotransmitters’ metabolism through changing the brain’s serotonin levels. In effect, what this achieves is to prevent the brain from receiving any hunger message by stimulating a particular group of neurotransmitters known as catecholamine, which includes dopamine, epinephrine, and norepinephrine.
Since phentermine is chemically close in structure to the amphetamines, users may become addicted to it. In many countries today, phentermine has become a controlled substance. The FDA would recommend its short-term use for a period of up to 12 weeks, in combination with healthy dieting and exercise. This is because after 12 weeks, phentermine would generally lose its appetite suppressing effects as the body gets adjusted to the drug dosage. However, there was a study whereby phentermine was used over a trial-period of 36 weeks without losing its effect. Nonetheless, it is recommended that this drug be taken either before breakfast or 1-2 hours after breakfast, due to the fact that it can cause the subject to develop insomnia. Never take phentermine in the evening, and always take it on an empty stomach once or twice a day.
Phentermine is known to be a relatively well-tolerated drug, yet it can produce side effects such as increased heart beat rate of over 100 beats per minute, and the attendant increased alertness. Though this is less pronounced compared to taking amphetamines, its long-term use may lead the subject to develop euphoria as a symptom of psychological addiction. Other symptoms include dizziness, blurred vision, or restlessness, and it may even hide the symptoms of extreme tiredness. Therefore, when on this medication, do not perform hazardous activities such as driving or operating machinery. Also do not crush any phentermine tablets or chew open any capsules, swallow them whole. The patient should gradually stay off this medicine instead of stopping the program suddenly, and such timing should coincide with the gradual weight loss achieved, as advised by the doctor. This is to minimize to the utmost extent whatever withdrawal symptoms may ensue.
The patient should stop taking phentermine if they begin to experience any emergency symptoms such as symptoms of an allergic reaction which includes swelling of the lips, face, or tongue, breathing difficulties, throat closing, or hives. Furthermore, if there are any instances of high blood pressure, which generally include blurred vision or severe headaches, irregular heartbeat, confusion, hallucinations, or abnormal behavior, make sure you contact your physician immediately.
When other less serious side effects surface, continue taking phentermine, but with the doctor’s knowledge of your symptoms that might include tremors, restlessness, anxiety, nervousness, dizziness, headaches, insomnia, dry mouth, constipation, diarrhea, or changes in the sex drive.
People with a history of high blood pressure, heart disease, arteriosclerosis, glaucoma, alcohol abuse, or drug abuse must avoid taking Phentermine. Additionally, if you have taken a monoamine oxidase inhibitor (MAOI), such as isocarboxazid (Marplan), tranylcypromine (Parnate), or phenelzine (Nardil) in the last 14 days you cannot take the medication.