Phenmetrazine hydrochloride is an oxazine appetite suppressant used in the treatment of obesity. It is an anorexigenic agent, widely employed to curb the appetite of the obese patient. In the USA, it was fomerly sold under the brand name of Preludin. Phenmetrazine hydrochloride belong to the oxazine group of compounds, being sympathomimetic amine, designated chemically as 2-phenyl-3-methyltetrahydro-1.4-oxazine hydrochloride. For clinical use, it is made available as tablets of 25 mg. It must be used with caution in hypertension of moderate degree.