Table 2: Central mechanisms of action of anti-obesity pharmacotherapies.

Central SubsystemDrugs targetsPossible receptor subtypes involved

Monoamine system (indirect agonists and subtype selective receptor antagonists)Single therapies
(i) Dex/fenfluramine (WD), fluoxetine(i) 5HT
(ii) Phentermine/Diethylpropion (ST)(ii) DA, NA
(iii) Sibutramine(iii) α 1, β 1, β 3 adrenergic and 5HT2B/C
(iv) Bupropion(iv) DA, NA
(v) Tesofensine(v) DA, NA, 5HT
(vi) Lorcaserin(vi) 5HT2C

Opioid system (μ-opioid receptor antagonist)(i) Naltrexone(i) μ-opioid
(ii) Topiramate(ii) AMPA/kainite glutamate*
(iii) Zonisamide(iii) 5HT, DA

Cannabinoid systemSingle therapies:
(i) Rimonabant (WD)(i) CB1
(ii) Taranabant (DC)(ii) CB1

Monoamine/Opioid systemBupropion/naltrexone(i) DA, NA/μ-opioid
Bupropion/zonisamide(ii) DA, NA/5HT, DA

Neuropeptide Y/Agouti-related peptide systemPramlintide/metreleptin(i) Calcitonin receptor/Leptin receptor

5HT: serotonergic, DA: dopaminergic, NA: noradrenergic, WD:withdrawn; DC: phase III trials discontinued; ST: short term;: unknown; AMPA: α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate.