Betaprodine is an opioid analgesic under international control according to the UN Single Convention 1961. It has been used in obstetrics, as pre-operative medication, for minor surgical procedures.

Picobenzide is a synthetic product which is of therapeutic interest owing to its neuroleptic, anti-inflammatory and spasmolytic action and because its properties are similar to those of the phenotiazines. The product is largely metabolized into the N-oxide form and is also partially eliminated in urine in an unaltered state.

Cyclazocine is a mixed opioid agonist/antagonist, an agonist of kappa opioid receptor, and a partial agonist of mu opioid receptor. The drug has analgesic activity and dose 0.25-0.5 mg/70 kg is equivalent to 10 mg/75 kg of morphine. Cyclazocine is a long-acting mu-opioid antagonist in human and was studied for the treatment of addiction to opioids and cocaine. Induction of the drug leads to dysphoria, hallucination, irritability, and sleeplessness.

Somantadine, an adamantane derivative, is an antiviral agent. Somantadine was synthesized by Pennwalt and has been undergoing tests for the treatment of herpes virus for nearly five years.

FEPRADINOL is an analgesic, antipyretic and anti-inflammatory agent. Its anti-inflammatory activity does not seem to be related to an inhibitory effect on prostaglandin biosynthesis.

Bemarinone (ORF 16600) is a positive inotropic and vasodilator agent with potential clinical utility in the management of congestive heart failure. The compound selectively and competitively inhibited cyclic AMP phosphodiesterase fraction III. However, further studies were discontinued

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.

Mesulergine, an antagonist of 5-HT2C, and dopamine receptors was studied in clinical trials for the treatment of Parkinson's disease. However, further, development was discontinued due to toxicological observations in animal experiments.

Feloprentan is an endothelin receptor antagonist.

Metheptazine was studied as an analgesic agent.