Phenylmorpholines

Phenmetrazine, sold under the brand name Preludin among others, is a stimulant drug first synthesized in 1952 and originally used as an appetite suppressant, but withdrawn from the market in the 1980s due to widespread misuse. It was initially replaced by its analogue phendimetrazine (under the brand name Prelu-2) which functions as a prodrug to phenmetrazine, but now it is rarely prescribed, due to concerns of misuse and addiction. Chemically, phenmetrazine is a substituted amphetamine containing a morpholine ring or a substituted phenylmorpholine.

Phendimetrazine, sold under the brand name Bontril among others, is a stimulant medication of the morpholine chemical class used as an appetite suppressant.

Morazone (Novartrina, Orsimon, Rosimon-Neu, Tarcuzate) is a nonsteroidal anti-inflammatory drug (NSAID), originally developed by the German pharmaceutical company Ravensberg in the 1950s, which is used as an analgesic. It produces phenmetrazine as a major metabolite and has been reported to have been abused as a recreational drug in the past.

Oxaflozane (INN; brand name Conflictan) is an antidepressant and anxiolytic drug that was introduced by Solvay in France in 1982 for the treatment of depression but has since been discontinued. It is a prodrug of flumexadol (N-dealkyloxaflozane; 2-(3-trifluoromethylphenyl)morpholine; CERM-1841 or 1841-CERM), which is reported to act as an agonist of the serotonin 5-HT1A (pKi = 7.1) and 5-HT2C (pKi = 7.5) receptors and, to a much lesser extent, of the 5-HT2A (pKi = 6.0) receptor. In addition to its serotonergic properties, oxaflozane may also produce anticholinergic side effects at high doses,

Fenbutrazate (INN), also known as phenbutrazate (BAN), is a psychostimulant used as an appetite suppressant under the trade names Cafilon, Filon, and Sabacid in Europe, Japan, and Hong Kong. It is a derivative of phenmetrazine and may function as a prodrug due to its similarity to phendimetrazine.

Radafaxine (developmental code GW-353,162; also known as '(2S,3S)-hydroxybupropion or (S,S)-hydroxybupropion') is a norepinephrine–dopamine reuptake inhibitor (NDRI) which was under development by GlaxoSmithKline in the 2000s for a variety of different indications but was never marketed. These uses included treatment of restless legs syndrome, major depressive disorder, bipolar disorder, neuropathic pain, fibromyalgia, and obesity. Regulatory filing was planned for 2007, but development was discontinued in 2006 due to "poor test results".

Manifaxine (developmental code name GW-320,659) is a norepinephrine–dopamine reuptake inhibitor developed by GlaxoSmithKline through structural modification of radafaxine, an isomer of hydroxybupropion and one of the active metabolites of bupropion. Manifaxine was researched for treatment of attention deficit hyperactivity disorder (ADHD) and obesity and was found to be safe, reasonably effective, and well-tolerated for both applications. However, no results were reported following these initial trials and development was discontinued.

PD-128,907 is a drug used in scientific research which acts as a potent and selective agonist for the dopamine D2 and D3 receptors. It is used for studying the role of these receptors in the brain, in roles such as inhibitory autoreceptors that act to limit further dopamine release, as well as release of other neurotransmitters. In animal studies, it has been shown to reduce toxicity from cocaine overdose.

Fenmetramide is a drug which was patented as an antidepressant by McNeil Laboratories in the 1960s. The drug was never marketed. It is the 5-ketone derivative of phenmetrazine and would similarly be expected to produce psychostimulant effects, though pharmacological data is lacking.

PF-219,061 is a drug that was under development by Pfizer which acts as a potent and highly selective agonist for the dopamine D3 receptor. It was under development as a potential medication for the treatment of female sexual dysfunction. It did not advance into clinical trials.