In 1959, phentermine first received approval from the United States FDA as an appetite-suppressing drug. Phentermine hydrochloride then became available in the early 1970s. It was previously sold as Fastin from King Pharmaceuticals for SmithKline Beecham, but in 1998, it was removed from the market. Medeva Pharmaceuticals sells the name brand of phentermine called Ionamin and Gate Pharmaceuticals sells it as Adipex-P. Phentermine is also currently sold as a generic. Since the drug was approved, almost no clinical studies have been performed.
Phentermine was marketed with fenfluramine as a combination appetite suppressant and fat burning agent under the popular name Fen-Phen. In 1997, after 24 cases of heart valve disease in Fen-Phen users, fenfluramine and dexfenfluramine were voluntarily taken off the market at the request of the FDA.[10] Studies later proved nearly 30% of people taking fenfluramine or dexfenfluramine had abnormal valve findings.
Phentermine is still available by itself in most countries, including the US. However, because it is similar to amphetamine, it is classified as a controlled substance in many countries. Internationally, phentermine is a schedule IV drug under the Convention on Psychotropic Substances.[11] In the United States, it is classified as a Schedule IV controlled substance under the Controlled Substances Act. In contrast, amphetamine preparations are classified as Schedule II controlled substances.
Phentermine is being studied in combination with other medications for obesity. The first such combination is the appetite suppressant phentermine/topiramate (Qsymia formerly Qnexa). In 2012, the FDA approved its sale in the United States.[12]
Phentermine, a contraction of "phenyl-tertiary-butylamine", is a psychostimulant drug of the substituted amphetamine chemical classes, with pharmacology similar to amphetamine. It is used medically as an appetite suppressant.
Phentermine is approved in Australia as an appetite suppressant and is medically prescribed as a diet pill; intended for obese patients and patients that are considered a medical risk due to weight. Phentermine is a prescription that helps aid weight-loss and is designed for short-term use with a combination of exercise and a healthy diet.
In the USA, phentermine is FDA approved, and is currently being studied in combination with other medications for obesity. The first such combination is the appetite suppressant phentermine/topiramate (Qsymia, formerly Qnexa). In 2012, the FDA approved its sale in the United States.
There are various phentermine brands and supplements available through tablets, capsules, and drinks such as: Vites, Adipex and Qsymia (previously known as Qnexa) available in various dosages. Manufacturers of phentermine diet pills have their own 37.5 mg dosages, Phentermine 37.5 mg tablets or capsules are generally manufactured by generic pharmaceutical groups.