FLETAZEPAM, a benzodiazepine derivative, is a centrally-acting muscle relaxant more effective than diazepam in preventing convulsions and muscle rigidity.

Uldazepam is a tranquilizer belonging to the 1.4‐benzodiazepine group.

Ripazepam (CI 683 or pyrazapon) is a pyrazolodiazepine that has anxiolytic effects. It is related to certain benzodiazepines such as zolazepam. In animal studies, it showed anxiolytic effects without sedative or depressant effects. In rats, it did not elicit a tumorigenic potential. Although ripazepam was found significantly superior to placebo and was well tolerated in neurotic patients, it has never been marketed for clinical use.

Gepirone (brand name Travivo) is an investigational azapirone antidepressant and anxiolytic drug in development for the treatment of major depressive disorder but has yet to be marketed. Like other azapirones, it acts as a selective partial agonist of the 5-HT1A receptor. Gepirone has been under development in the U.S. in an extended release form (referred to as Gepirone ER). It has been rejected multiple times by the FDA during the drug approval process and Phase III studies evaluating its use in the treatment of MDD were prematurely terminated. These were the initial Phase III studies of gepirone ER in MDD, and the effective dose range had not been determined. In March 2016, the FDA reversed its decision and gave gepirone ER a positive review, clearing the way for the drug to finally gain market approval in the U.S. In addition to its antidepressant and anxiolytic properties, gepirone has been found to improve symptoms of sexual dysfunction in men and women, similarly to the marketed 5-HT1A receptor agonist flibanserin. The pro-sexual effects appear to be independent of its antidepressant and anxiolytic effects. Mechanism of action studies have demonstrated that gepirone possesses a much greater selectivity for 5-HT1A receptors over dopamine D2 receptors. Long-term studies have shown that gepirone has a differential action at presynaptic (agonist) and post-synaptic (partial agonist) 5-HT1A receptors. Treatment with gepirone ER desensitizes presynaptic 5-HT1A receptors, which decreases serotonin autoregulatory inhibition and enhances activation of postsynaptic 5-HT1A receptors. As a partial agonist gepirone ER acts as an agonist when endogenous serotonin is not present and as an antagonist when endogenous serotonin is present. Overall, gepirone ER increases serotonin production when insufficient amounts are present, and decreases serotonin production when excess amounts are present. Gepirone has been tested in Phase II clinical trial as antidepressant medication for pharmacotherapy for cocaine dependent subjects.

Halazepam is a benzodiazepine derivative. It possesses anxiolytic, anticonvulsant, sedative and skeletal muscle relaxant properties. Halazepam is used to relieve anxiety, nervousness, and tension associated with anxiety disorders. Halazepam (Paxipam) is no longer commercially available in the United States. Common adverse effects are: hypotension, nausea, xerostomia, confusion, headache. Alcohol should be avoided while taking Paxipam as it causes drowsiness as well. Medications that also cause drowsiness should not be taken along with Paxipam. These include: Antidepressants, Pain relievers, Seizure medications, Muscle relaxants, Antihistamines, Sleeping pills and sedatives.

Prazepam is a benzodiazepine derivative and is indicated to treat symptoms of anxiety. Benzodiazepines are used to treat severe incapacitating symptoms or symptoms leading to an extreme suffering for the patient. Prazepam is believed to stimulate GABA receptors in the ascending reticular activating system. Since GABA is inhibitory, receptor stimulation increases inhibition and blocks both cortical and limbic arousal following stimulation of the brain stem reticular formation. Prazepam is a prodrug for N-desmethyl-diazepam, which is responsible for the therapeutic effects of prazepam. Prazepam was discontinued in USA.

Methaqualone is a depressant that modulates the activity of the GABA receptors in the brain and nervous system. It promotes relaxation, sleepiness and sometimes a feeling of euphoria. It causes a drop in blood pressure and slows the pulse rate. These properties are the reason why it was initially thought to be a useful sedative and anxiolytic. Common side effects of Methaqualone include dizziness, nausea, vomiting, diarrhea, abdominal cramps, fatigue, itching, rashes, sweating, dry mouth, tingling sensation in arms and legs, seizures and its depressant effects include reduced heart rate and respiration. The drug became banned in many countries and was withdrawn from many markets in the early 1980s.

EMYLCAMATE (STRIATRAN®), the carbamate ester of the tertiary alcohol methylpentanol, is a tranquilizing and muscle relaxant agent used for the treatment of anxiety and tension.

CAPTODIAME, also known as captodiamine, is a diphenylmethane derivative. It is a 5-HT2c receptor antagonist and agonist at sigma-1 and D3 dopamine receptors. It is an antihistamine which is used as a sedative and anxiolytic. CAPTODIAME is probably useful in preventing benzodiazepine withdrawal syndrome.

Chlormezanone (TRANCOPAL®) is a non-benzodiazepine that is used in the management of anxiety. It has been suggested for use in the treatment of muscle spasm. It binds to central benzodiazepine receptors which interact allosterically with GABA receptors. This potentiates the effects of the inhibitory neurotransmitter GABA, increasing the inhibition of the ascending reticular activating system and blocking the cortical and limbic arousal that occurs following stimulation of the reticular pathways. Chlormezanone (TRANCOPAL®) was discontinued worldwide in 1996 by Sanofi due to confirmed serious and rare cutaneous reactions (toxic epidermal necrolysis also known as Stevens-Johnson syndrome).