RTI-113

RTI-113

Identifiers
IUPAC name phenyl (2S,3S)-3-(4-chlorophenyl)-8-methyl-8-azabicyclo[3.2.1]octane-2-carboxylate
CAS Number	146145-17-7 N HCl: 141807-57-0 N
PubChem CID	9886801
ChemSpider	8062474 N
ChEMBL	CHEMBL608548 N
Chemical and physical data
Formula	C21H22ClNO2
Molar mass	355.85 g/mol
3D model (Jmol)	Interactive image
SMILES CN1C2CCC1[C@H]([C@H](C2)C3=CC=C(C=C3)Cl)C(=O)OC4=CC=CC=C4
InChI InChI=1S/C21H22ClNO2/c1-23-16-11-12-19(23)20(21(24)25-17-5-3-2-4-6-17)18(13-16)14-7-9-15(22)10-8-14/h2-10,16,18-20H,11-13H2,1H3/t16?,18-,19?,20+/m1/s1 N Key:AAEKULYONKUBOZ-MLFFRYNPSA-N N
NY (what is this?)

RTI(-4229)-113 (2β-carbophenoxy-3β-(4-chlorophenyl)tropane) 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.

In order for a DRI such as cocaine to induce euphoria PET scans on primates reveal that the DAT occupancy needs to be >60%. Limited reinforcement may be desirable because it can help with patient compliance. DAT occupancy was between 65-76% and 94-99% for doses of cocaine and RTI-113 that maintained maximum response rates, respectively. Whereas cocaine is a fast acting rapidly metabolized DRI, RTI-113 has a longer duration span.

Self-administration graphs are inverted U-shaped. More doses of cocaine need to be administered per session than for RTI-113 because cocaine doesn't last as long as RTI-113 does. It is easy to form the rash judgement that the NRI and SRI properties of cocaine are somehow having an additive effect on provoking self-administration of cocaine.

Although NRIs are known to inhibit DA reuptake in the prefrontal cortex where DATs are low in number, the fact that desipramine is not reliably self-administered makes it unlikely that NRIs are contributing to the addictive character of cocaine.