(-)-DDMS (S-Didesmethylsibutramine, (S)-DDMS) is one of sibutramine active metabolites. Sibutramine is widely used in the treatment of obesity. Sibutramine acts by inhibiting the reuptake of serotonin and noradrenaline in synapses, thereby enhancing both satiety and energy expenditure. In preclinical models (S)-Didesmethylsibutramine affected locomotor behavior and the Porsolt test but appeared to be completely inactive on food intake. (S)-enantiomers of didesmethylsibutramine may, to some extent, contribute to sibutramine’s side effect profile.

McN-5652 is one of a series of substituted pyrrolo-isoquinolines that, as a group, potently inhibit the uptake of one or more of the monoamines, norepinephrine, serotonin and dopamine. Receptor binding experiments indicated that McN-5652 has a weak affinity for serotonin 5-HT2 and alpha-1 adrenergic receptors. Abnormalities of the 5-HT transporter have been suggested in mood disorders, since it is one of the major binding sites of antidepressants. (+)-[11C]McN 5652 is an appropriate radiotracer to quantify 5-HT transporters in regions with relatively high concentration of 5-HT transporters, such as the midbrain, thalamus, and basal ganglia, and should prove useful in elucidating abnormalities of 5-HT transmission in neuropsychiatric conditions.

4-Methoxymethamphetamine (PMMA, para-Methoxymethamphetamine) is a stimulant and psychedelic drug closely related to the amphetamine-class serotonergic drug para-methoxyamphetamine (PMA). Little is known about the pharmacological properties, metabolism, and toxicity of 4-Methoxymethamphetamine. Because of its structural similarity to para-methoxyamphetamine, which has known toxicity in humans, it is thought to have considerable potential to cause harmful side effects or death in overdose. In the early 2010s, a number of deaths in users of the drug MDMA were linked to misrepresented tablets and capsules of 4-Methoxymethamphetamine. In 2010–2013, a cluster of 29 fatal poisonings related to the toxic designer drug 4-Methoxymethamphetamine was revealed in Norway. The toxicity of PMMA is regarded as substantially higher than for amphetamine, methamphetamine, and MDMA, as indicated by 131 fatal and 31 nonfatal poisonings associated with the abuse of 4-Methoxymethamphetamine worldwide. The toxicity of 4-Methoxymethamphetamine is positively correlated with the 4-Methoxymethamphetamine dose and the blood drug level, but the existing literature indicates that certain human subjects may have an increased risk of 4-Methoxymethamphetamine toxicity. 4-Methoxymethamphetamine, like PMA most likely acts as a selective serotonin releasing agent (SSRA) with weak effects on dopamine and norepinephrine transporters. However, relative to MDMA, it is considerably less effective as a serotonin releaser with properties more akin to a reuptake inhibitor in comparison. It evokes robust hyperthermia while producing only modest hyperactivity and serotonergic neurotoxicity, substantially lower than that caused by MDMA.