Phentermine is actually a chemical contraction for “phenyl-tertiary-butylamine” and is one of the amphetamines once in great use as an appetite suppressant. Phentermine is a proven prescription weight loss pill that works and continues to be approved as a medication that suppresses appetite and is intended to be used along with a healthy diet, a generous amount of exercise and modification of one’s dietary behaviors. Phentermine has been designed for use in those who are severely obese and who carry medical risks because of their excess weight. It works by releasing chemicals into the brain which, in turn, control the appetite centers of the brain.
Phentermine is marketed under numerous names, the most common being Adipex-P, Ionamin, Fastin, and Zantryl. Phentermine’s history dates back to its initial approval for weight loss in 1959 and became widely available and widely used in the 1970's. Phentermine is currently sold under the names Ionamin and Adipex-P, as well as in its generic form.
Interestingly, no clinical trials were held on the drug at the time it was approved and off-label use of Phentermine became common, such as the fenfluramine-phenterminecombination, called Fen-Phen. In 1997, twenty four cases of heart valvular disease was uncovered in Fen-Phen users and it was asked that fenfluramine be voluntarily removed from the market shortly therafter. It was later found that up to 30 percent of users of fenfluramine developed heart valve problems. Phentermine 37.5 remained on the market. Because of its classification as an amphetamine controlled substance, Phentermine is less used in the US as it used to be. It is scheduled as a Schedule IV controlled substance under the US Controlled Substances Act.
Phentermine acts on the hypothalamus and releases norepinephrine, a chemical neurotransmitter that normally reduces hunger. It also works outside of the brain, allowing epinephrine to break down stored fat but this effect is felt to be less useful than its brain effects. It is approved for use as an appetite suppressant for someone who plans to use the drug along with a healthy diet and exercise for less than twelve weeks total. It shouldn’t be used if the individual is allergic to phentermine or anyone taking an MAO inhibitor. Those with severely high blood pressure or have an untreated overactive thyroid gland should also be taking phentermine. It can’t be used in pregnancy or if you’re taking another form of diet pill or herbal supplement to reduce the appetite. It should not also be used with severe high blood pressure, diabetes, high cholesterol or high lipid levels.
Medications which may interact with phentermine 37.5 include dexfenfluramine, fenfluramine, MAOIs because of the risk of secondary side effects, including headache, high blood pressure, slow heart rate, elevated temperature or a potentially fatal lung problem.
When taken alone, phentermine can have side effects all on its own. Its major side effects include a rapid heartbeat, high blood pressure, palpitations, restlessness and insomnia. It is an addictive drug and can therefore cause a physical dependence on the drug when used for long periods of time. Generally the side effects are minimal and it can be taken safely.