Otenabant (CP-945,598) is Pfizer developed as a potent and selective cannabinoid receptor CB1 antagonist with Ki of 0.7 nM, which exhibits 10,000-fold greater selectivity against human CB2 receptor, for treatment of obesity. In clinical trial III Pfizer decided to discontinue the development program based on changing regulatory perspectives on the risk/benefit profile of the CB1 class and likely new regulatory requirements for approval.

Drinabant is a selective CB1 receptor antagonist under investigation varyingly as a treatment for obesity, schizophrenia, Alzheimer's disease, Parkinson's disease, and nicotine dependence. Drinabant may be useful to treat the cognitive deficits in schizophrenia and as a co-treatment with currently available antipsychotics. Coadministration of olanzapine and drinabant attenuated body weight gain, diminishing the enhanced food intake while maintaining increased energy expenditure and decreased motility. Sanofi has outlicensed global development and commercialization rights to drinabant to Opiant Pharmaceuticals, which said it plans to start developing the acute cannabinoid overdose (ACO) candidate in the 2019 year. Opiant said drinabant will be developed as an injectable for administration in an emergency department setting.

Taranabant is a highly selective cannabinoid-1 (CB1) receptor inverse agonist developed by Merck & Co for the treatment of obesity. The Phase III taranabant study involved about 2,400 patients and was to be conducted for two years. In March 2008, after completion of 52 weeks of the study, Merck reported positive results of the drug in conjunction with diet and exercise in obese patients. The patients experienced double the amount of weight loss by taking 2mg of taranabant when compared to the patients treated with placebo. However, in October 2008, the company discontinued the Phase III programme and clinical development of taranabant because of its side effects. The drug showed gastrointestinal and psychiatric side effects such as increased anxiety, depression and irritability. Merck had previously planned to file for regulatory approval with the US Food and Drug Administration in 2008, but subsequently withdrew it.

Pravadoline is the anti-nociceptive agent, which has analgesic efficacy against postoperative pain in humans. Pravadoline inhibits the enzyme cyclooxygenase, but in contrast to cyclooxygenase-inhibiting NSAIDs does not produce gastrointestinal irritation. Pravadoline inhibited the synthesis of prostaglandins in mouse brain both in vitro and ex vivo. Pravadoline demonstrated only weak anti-inflammatory activity relative to its anti-nociceptive potency. Single doses of pravadoline were safe and effective in humans, without serious adverse events. Single oral administration of pravadoline maleate induced acute tubular necrosis in male and female beagle dogs.

ORG-28611 (SCH-900,111) is a potent cannabinoid receptor full agonist, developed by Organon International for treatment pain. In preclinical studies, Org 28611 exhibited high affinity for both CB1 and CB2 cannabinoid receptors, as determined by radioligand competition binding assays and rapidly metabolized by mouse and human hepatic microsomes and showed higher total levels in the brain compared to plasma. In clinical trials, Org 28611 does not provide enough sedation for outpatient surgical procedures, does not induce anterograde amnesia and causes undesirable subjective effects at higher doses. However, bolus doses up to 3 μ/kg (with maximum initial plasma concentrations of 24 ng/mL) or mean plasma levels up to 4 ng/mL are well tolerated and make it worthwhile to further explore the analgesic or antiemetic properties.

JTE-907 is selective high-affinity cannabinoid CB2 receptor inverse agonist. JTE-907 showed a concentration-dependent increase of forskolin-stimulated cAMP production in CHO cells expressing human and mouse CB2 in vitro. In mice model of atopic dermatitis, JTE-907 suppresses spontaneous itch-associated responses of NC mice without adverse effects such as weight loss.

(-)-∆8-Tetrahydrocannabinol (∆8-THC) has a very similar pharmacologic profile as (-)-∆9-tetrahydrocannabinol (∆9-THC), the most active constituent of cannabis. Delta-8-tetrahydrocannabinol (THC) has activity in man similar to that of its double-bond isomer, delta-9-THC. The spatial orientation of the side chain seems to play a pivotal role in cannabinergic activity. Introduction of a triple bond in the benzylic position of the n-heptyl-D8-THC analogue led to the classical cannabinoid AMG-1 with high CB1 and moderate CB2 affinity. AMG-1 is an analgesic drug which is a cannabinoid agonist.