RimonabantRimonabant (Acomplia, SR141716A)

5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-N-(piperidin-1-yl)-1H-pyrazole-3-carboxamide

Aliases.SR141716A · Acomplia · Zimulti

The first anti-obesity drug targeting CB1. Marketing authorisation revoked in 2008: depression, suicidality. A textbook pharmacovigilance case.

Updated on 1 May 2026

Level of detail

Identifiers

Formula: C₂₂H₂₁Cl₃N₄O
Molar mass: 463.79 g·mol⁻¹
CAS: 168273-06-1
PubChem CID: 104850
First described: 1994
Origin: Sanofi-Aventis (withdrawn medicine)
InChIKey: JZCPYUJPEARBJL-UHFFFAOYSA-N

In plain terms

Rimonabant was the first anti-obesity medicine acting on the cannabinoid receptors. Launched in 2006, withdrawn in 2008 after several cases of depression and suicide. Its history is studied in pharmacovigilance.

Receptors and activity

CB1
Ki ≈ 1,98 nMInverse agonist
CB2
Ki ≈ 514 nMInverse agonist

Agonist
Partial agonist
Antagonist
Modulator
Inverse agonist

Hover over a row for the precise value (Ki, EC50…)

Subjective signature

Hover over an axis to read its definition.

Calm
15
Clarity
65
Sleep
20
Appetite
10
High
15

Editorial estimate, not clinical.

Pharmacology

Rimonabant (Acomplia®) is the first CB1 antagonist / inverse agonist to be marketed - Sanofi-Aventis, EMA marketing authorisation June 2006. It reduced weight by ≈ 4–5 kg vs placebo in the RIO trials (Van Gaal et al., Lancet 2005, PMID 15836887). The marketing authorisation was revoked by the EMA in October 2008 (CHMP reference EMEA/H/C/666) after an accumulation of reports of depressive episodes and suicidality (≈ 2× the placebo risk). It never received FDA marketing authorisation. A textbook case: it shows that tonic inhibition of the endocannabinoid system destabilises mood. It remains an essential research tool.

Key sources.