Rimonabant is an anti-obesity drug that works by blocking the cannabinoid receptor type 1 (CB1). It was the first selective CB1 receptor blocker and was effective in reducing appetite and aiding in smoking cessation. However, it was suspended in 2009 due to psychiatric side effects including depression, anxiety, and suicidal tendencies that were linked to its mechanism of blocking CB1 receptors in the brain. CB1 receptors are involved in modulating emotion and stress responses.

1. rimonabant
By dr salman kareem
1st yr resident
Department of psychiatry

2. rimonabant
• Anorectic anti obesity drug
• Inverse agonist of cannabinoid receptor
• first selective CB1 receptor blocker.
• Main effect in the reduction of appetite
• Started in july 2006
• Suspended in 16 Jan 2009 by EMEA

3. Endocannabinoid system (ECS): Overview
Gelfand EV, Cannon CP. J Am Coll Cardiol. 2006;47:1919-26.
Pagotto U et al. Ann Med. 2005;37:270-5.
Endocannabinoid ligands
• Produced on demand
• Act locally
• Inactivated rapidly
• Bind to transmembrane G-protein receptors,
principally inhibiting neurotransmitter release
Cannabinoid receptor type 1 (CB1)
Cannabinoid receptor type 2
(CB2)
Cannabinoid receptor type 1
(CB1)
Most widespread CB receptor Immune cells
(brain, spinal cord; peripheral nervous
system, organs, tissues)

4. Implications of CB1 receptor activation
Central nervous system Peripheral tissue
Appetite Motivation
to eat/smoke
Liver GI tract
Skeletal muscle
Lipogenesis
Adipose tissue
Altered glucose metabolism
Gelfand EV, Cannon CP. J Am Coll Cardiol. 2006;47:1919-26.
Pagotto U et al. Ann Med. 2005;37:270-5.
Hypothalamus Limbic
system

5. uses
• Smoking cessation – found to be effective in assisting
some members to quit smoking.
Studies with Rimonabant and Tobacco Use (STRATUS)
done in 6000 subjects shows it aods in smoking and
prevents weight gain in former smokers.
COCHRAne review – mayincrease the odds of quitting
approximately 1n half folds.

6. • Addiction - reduced resumption of cocaine-seeking
responses.
– also reduce ethanol- and opiate-seeking behavior.
• Blockage of cannabis effects - Rimonabant blocks
the psychoactiveand some of the cardiovascular effects of
Δ9-tetrahydrocannabinol (THC) in humans.
• Reverse marijuana

7. • Memory - hypothesised that rimonabant may improve
short-term memory.
• Effect on physical activity
• Effect on male fertility

8. Side effects
• Depression
• Nausea
• Anxiety
• Suicidal Tendency
• Unpredictable mood swings
• Insomnia

9. • CB(1) receptors are widely distributed in the central nervous
system and are involved in the modulation of emotion,
stress and habituation responses, behaviours that are
thought to be dysregulated in human psychiatric disorders.
• CB(1) receptor activation may, in some cases, precipitate
episodes of psychosis and panic, while its inhibition may
lead to behaviours reminiscent of depression and anxiety-related
disorders

10. Study published in LANCET
• Rimonabant patient has 2.5 times risk discontinuinf for
depression
• 3.5 times discontinuing due to anxiety.