Methylphenidate, sold under the brand names Ritalin and Concerta among others, is a central nervous system (CNS) stimulant used medically to treat attention deficit hyperactivity disorder (ADHD) and, to a lesser extent, narcolepsy. It is a primary medication for ADHD ; it may be taken by mouth or applied to the skin, and different formulations have varying durations of effect, commonly ranging from 2–4 hours.
(–)-2-β-Carbomethoxy-3-β-(4-fluorophenyl)tropane is a stimulant drug used in scientific research. CFT is a phenyltropane based dopamine reuptake inhibitor and is structurally derived from cocaine. It is around 3-10x more potent than cocaine and lasts around 7 times longer based on animal studies. While the naphthalenedisulfonate salt is the most commonly used form in scientific research due to its high solubility in water, the free base and hydrochloride salts are known compounds and can also be produced. The tartrate is another salt form that is reported.
(+)-CPCA is a stimulant drug similar in structure to pethidine and to RTI-31, but nocaine is lacking the two-carbon bridge of RTI-31's tropane skeleton. This compound was first developed as a substitute agent for cocaine.
Troparil is a stimulant drug used in scientific research. Troparil is a phenyltropane-based dopamine reuptake inhibitor (DRI) that is derived from methylecgonidine. Troparil is a few times more potent than cocaine as a dopamine reuptake inhibitor, but is less potent as a serotonin reuptake inhibitor, and has a duration spanning a few times longer, since the phenyl ring is directly connected to the tropane ring through a non-hydrolyzable carbon-carbon bond. The lack of an ester linkage removes the local anesthetic action from the drug, so troparil is a pure stimulant. This change in activity also makes troparil slightly less cardiotoxic than cocaine. The most commonly used form of troparil is the tartrate salt, but the hydrochloride and naphthalenedisulfonate salts are also available, as well as the free base.
Ethylphenidate (EPH) is a psychostimulant and a close analog of methylphenidate.
LR-5182 is a stimulant drug which acts as a norepinephrine–dopamine reuptake inhibitor, structurally related to the better known drug fencamfamine. It was developed by the pharmaceutical company Eli Lilly in the 1970s, and researched for potential use as an antidepressant, although never marketed. LR-5182 has two stereoisomers, both of which are active, although one isomer blocks reuptake of only dopamine and noradrenaline, while the other blocks reuptake of serotonin as well.
Difluoropine (O-620) is a stimulant drug synthesised from tropinone, which acts as a potent and selective dopamine reuptake inhibitor. Difluoropine is unique among the tropane-derived dopamine reuptake inhibitors in that the active stereoisomer is the (S) enantiomer rather than the (R) enantiomer, the opposite way round compared to natural cocaine. It is structurally related to benztropine and has similar anticholinergic and antihistamine effects in addition to its dopamine reuptake inhibitory action.
HDMP-28 or methylnaphthidate is a piperidine based stimulant drug, closely related to methylphenidate, but with the benzene ring replaced by naphthalene. It is a potent dopamine reuptake inhibitor, with several times the potency of methylphenidate and a short duration of action, and is a structural isomer of another potent dopamine reuptake inhibitor, N,O-Dimethyl-4-(2-naphthyl)piperidine-3-carboxylate. It has been sold as a designer drug since around 2015.
2-Benzylpiperidine is a stimulant drug of the piperidine class. It is similar in structure to other drugs such as methylphenidate and desoxypipradrol but around one twentieth as potent, and while it boosts norepinephrine levels to around the same extent as d-amphetamine, it has very little effect on dopamine levels, with its binding affinity for the dopamine transporter around 175 times lower than for the noradrenaline transporter. 2-benzylpiperidine is little used as a stimulant, with its main use being as a synthetic intermediate in the manufacture of other drugs.
O-2172 is a drug developed by Organix Inc, which acts as a stimulant and potent dopamine reuptake inhibitor. It is an analogue of methylphenidate where the phenyl ring has had a 3,4-dichloro substitution added, and the piperidine ring has been replaced by cyclopentane. It is around 1/3 the potency of methylphenidate, demonstrating that even with the important binding group of the nitrogen lone pair removed entirely, selective DAT binding and reuptake inhibition is still possible.
RTI(-4229)-113 is a stimulant drug which acts as a potent and fully selective dopamine reuptake inhibitor (DRI). It has been suggested as a possible substitute drug for the treatment of cocaine addiction. "RTI-113 has properties that make it an ideal medication for cocaine abusers, such as an equivalent efficacy, a higher potency, and a longer duration of action as compared to cocaine." Replacing the methyl ester in RTI-31 with a phenyl ester makes the resultant RTI-113 fully DAT specific. RTI-113 is a particularly relevant phenyltropane cocaine analog that has been tested on squirrel monkeys. RTI-113 has also been tested against cocaine in self-administration studies for DAT occupancy by PET on awake rhesus monkeys. The efficacy of cocaine analogs to elicit self-administration is closely related to the rate at which they are administered. Slower onset of action analogs are less likely to function as positive reinforcers than analogues that have a faster rate of onset.
Naphyrone, also known as O-2482 and naphthylpyrovalerone, is a substituted cathinone drug derived from pyrovalerone that acts as a triple reuptake inhibitor, producing stimulant effects and has been reported as a novel designer drug. No safety or toxicity data is available on the drug.
3,4-Dichloromethylphenidate is a stimulant drug related to methylphenidate. Dichloromethylphenidate is a potent psychostimulant that acts as both a dopamine reuptake inhibitor and norepinephrine reuptake inhibitor, meaning it effectively boosts the levels of the norepinephrine and dopamine neurotransmitters in the brain, by binding to, and partially blocking the transporter proteins that normally remove those monoamines from the synaptic cleft.
Methiopropamine (MPA) is an organic compound structurally related to methamphetamine. Originally reported in 1942, the molecule consists of a thiophene group with an alkyl amine substituent at the 2-position. It appeared for public sale in the UK in December 2010 as a "research chemical" or "legal high", recently branded as Blow. It has limited popularity as a recreational stimulant.
3,4-Dimethylmethcathinone (3,4-DMMC) is a stimulant drug first reported in 2010 as a designer drug analogue of mephedrone, apparently produced in response to the banning of mephedrone, following its widespread abuse in many countries in Europe and around the world. 3,4-DMMC has been seized as a designer drug in Australia. In vitro, 3,4-DMMC was shown to be a monoamine transporter substrate that potently inhibits norepinephrine and serotonin reuptake, and to a lesser extent dopamine reuptake.
HDEP-28 or ethylnaphthidate is a piperidine based stimulant drug, closely related to ethylphenidate, but with the benzene ring replaced by naphthalene. It is even more closely related to HDMP-28, which acts as a potent serotonin–norepinephrine–dopamine reuptake inhibitor with several times the potency of methylphenidate and a short duration of action. It has been sold as a designer drug since around 2015.
4-Fluoromethylphenidate is a stimulant drug that acts as a higher potency dopamine reuptake inhibitor than the closely related methylphenidate.
1-Methyl-3-propyl-4-(p-chlorophenyl)piperidine is a drug developed by a team led by Alan Kozikowski, which acts as a potent dopamine reuptake inhibitor, and was developed as a potential therapeutic agent for the treatment of cocaine addiction. As with related compounds such as nocaine, it is a structurally simplified derivative of related phenyltropane compounds. Its activity at the serotonin and noradrenaline transporters has not been published, though most related 4-phenylpiperidine derivatives are relatively selective for inhibiting dopamine reuptake over the other monoamine neurotransmitters. While several of its isomers are active, the (3S,4S)-enantiomer is by far the most potent. The rearranged structural isomer 2-[1-(4-chlorophenyl)butyl]piperidine is also a potent inhibitor of dopamine reuptake.
3-Bromomethylphenidate (3-Br-MPH) is a compound from the phenidate family, which has reportedly been sold as a designer drug. It showed the most potent binding to the dopamine transporter of a series of ring-substituted methylphenidate derivatives, and produced stimulant effects in animal studies.
