Mepenzolate is a postganglionic parasympathetic inhibitor. It decreases gastric acid and pepsin secretion and suppresses spontaneous contractions of the colon. It specifically antagonizes muscarinic receptors. Mepenzolate is marketed under the brand name CANTIL. CANTIL is indicated for use as adjunctive therapy in the treatment of peptic ulcer. It has not been shown to be effective in contributing to the healing of peptic ulcer, decreasing the rate of recurrence, or preventing complications.

Promazine (Sparine) is a phenothiazine neuroleptic used for short-term management of moderate to severe psychomotor agitation and treatment of agitation and restlessness in the elderly. Promazine is an antagonist at types 1, 2, and 4 dopamine receptors, 5-HT receptor types 2A and 2C, muscarinic receptors 1 through 5, alpha(1)-receptors, and histamine H1-receptors. Promazine's antipsychotic effect is due to antagonism at dopamine and serotonin type 2 receptors, with greater activity at serotonin 5-HT2 receptors than at dopamine type-2 receptors. This may explain the lack of extrapyramidal effects. Promazine does not appear to block dopamine within the tuberoinfundibular tract, explaining the lower incidence of hyperprolactinemia than with typical antipsychotic agents or risperidone. Antagonism at muscarinic receptors, H1-receptors, and alpha(1)-receptors also occurs with promazine. Promazine is not approved for human use in the United States. It is available in the US for veterinary use under the names Promazine and Tranquazine.

Nylidrin (Buphenine, Arlidin) is a beta-adrenergic agonist. Nylidrin causes peripheral vasodilation, a positive inotropic effect, and increased gastric volume of gastric juice. It is used in the treatment of peripheral vascular disorders and premature labor. In peripheral vascular disorders, Arlidin (nylidrin HCl) increases walking ability and promotes healing of trophic ulcers. Nylidrin hydrochloride acts predominantly by beta-receptor stimulation. Beta stimulation with nylidrin has been demonstrated in a variety of isolated tissues from rabbits, guinea pigs and dogs. It has been shown to dilate arterioles in skeletal muscle and to increase cardiac output in the anesthetized dog and cat and in unanesthetized man. An increase in cerebral blood flow and a decrease in vascular resistance has also been reported. The result of this combination of actions is a greater blood supply to ischemic tissues, with usually minimal change in blood pressure. Arlidin may be of benefit in elderly patients with mild to moderate symptoms that are commonly associated with organic mental disorders. Short-term (3 months’ duration) and long-term (12 months’ duration) clinical studies have demonstrated a modest improvement in ability to perform general activities of daily living, self-care and in a capability for social interactions. The mechanism whereby nylidrin may provide relief of selected symptoms in some elderly patients with organic brain disorders is not known.

Pipenzolate bromide (JB-323), an anticholinergic agent, which binds to muscarinic acetylcholine receptors as an antagonist. Pipenzolate bromide was studied as an antispasmodic agent, and to treat peptic ulcer.

Pyrvinium (Viprynium) is an anthelmintic effective for pinworms. Pyrvinium is used in the treatment of enterobiasis caused by Enterobius vermicularis (pinworm). Pyrvinium has being shown to be a potent inhibitor of Wnt signaling (EC(50) of ∼10 nM). Pyrvinium binds all casein kinase 1 (CK1) family members in vitro at low nanomolar concentrations and pyrvinium selectively potentiates casein kinase 1α (CK1α) kinase activity. Pyrvinium pamoate (PP) is a potent noncompetitive inhibitor of the androgen receptor (AR). A noncompetitive AR inhibitor pyrvinium has significant potential to treat CRPC, including cancers driven by ligand-independent AR signaling.

Procyclidine is a muscarinic antagonist that crosses the blood-brain. Procyclidine hydrochloride (brand name Kemadrin) is a synthetic antispasmodic compound of relatively low toxicity. It has been shown to be useful for the symptomatic treatment of parkinsonism (paralysis agitans) and extrapyramidal dysfunction caused by tranquilizer therapy. Procyclidine hydrochloride was developed at The Wellcome Research Laboratories as the most promising of a series of antiparkinsonism compounds produced by chemical modification of antihistamines. Kemadrin is indicated in the treatment of parkinsonism including the postencephalitic, arteriosclerotic, and idiopathic types. Partial control of the parkinsonism symptoms is the usual therapeutic accomplishment. Procyclidine hydrochloride is usually more efficacious in the relief of rigidity than tremor; but tremor, fatigue, weakness, and sluggishness are frequently beneficially influenced. It can be substituted for all the previous medications in mild and moderate cases. For the control of more severe cases, other drugs may be added to procyclidine therapy as indications warrant. The mechanism of action is unknown. It is thought that procyclidine acts by blocking central cholinergic receptors, and thus balancing cholinergic and dopaminergic activity in the basal ganglia. Pharmacologic tests have shown that procyclidine hydrochloride has an atropine-like action and exerts an antispasmodic effect on smooth muscle. It is a potent mydriatic and inhibits salivation. It has no sympathetic ganglionblocking activity in doses as high as 4 mg/kg, as measured by the lack of inhibition of the response of the nictitating membrane to preganglionic electrical stimulation.

Tridihexethyl is a synthetic anticholinergic agent which was marketed under the brand name Pathilon as an adjunct in the treatment of peptic ulcer disease. However, it is no longer available in the US market. Tridihexethyl may block all three types of muscarinic receptors including M-1 receptors in the CNS and ganglia, M-2 receptors in the heart, and M-3 receptors. The muscarinic acetylcholine receptors mediate various cellular responses including inhibition of adenylate cyclase, the breakdown of phosphoinositides, and modulation of potassium channels through the action of G proteins. Tridihexethyl inhibits vagally mediated reflexes by antagonizing the action of acetylcholine. This, in turn, reduces the secretion of gastric acids in the stomach. Tridihexethyl was also examined for effect on patients with acquired nystagmus where four out of six patients showed improvement, but due to the profile usage of Tridihexethyl to treat nystagmus was limited.

Buclizine, a piperazine derivative, is a sedating antihistamine with antimuscarinic and moderate sedative action. The drug is used mainly for its antiemetic action, particularly in the prevention of motion sickness, and in the treatment of migraine in combination with analgesics. The following side/adverse effects have been selected on the basis of their potential clinical significance: drowsiness; Incidence less frequent; blurred vision; dryness of mouth, nose, and throat; headache; nervousness, restlessness, or trouble in sleeping; upset stomach. The following drug interactions have been selected on the basis of their potential clinical significance: alcohol; anticholinergics or other medications with anticholinergic activity; apomorphine.

Pentolinium (brand name Ansolysen) is a ganglionic cholinergic antagonist, acting on alpha 3 beta 4 neuronal nicotinic acetylcholine receptors (nAChRs). It was used as an antihypertensive drug during surgery or to control hypertensive crises, but Ansolysen was discontinued. Pentolinium inhibits release of adrenaline and noradrenaline from adrenergic nerves.

CYCRIMINE is an antispasmodic drug used for the treatment of Parkinson's disease (PD). It binds the muscarinic acetylcholine receptor M1, effectively reducing levels of acetylcholine. This decrease in acetylcholine restores the normal dopamine-acetylcholine balance and relieves the symptoms of PD.