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.

Propantheline is an antimuscarinic agent used for the treatment of excessive sweating (hyperhidrosis), cramps or spasms of the stomach, intestines (gut) or bladder, and involuntary urination (enuresis). It can also be used to control the symptoms of irritable bowel syndrome and similar conditions. Propantheline is one of a group of antispasmodic medications which work by blocking the action of the chemical messenger acetylcholine, which is produced by nerve cells, to muscarinic receptors present in various smooth muscular tissues, in places such as the gut, bladder, and eye. Normally, the binding of acetylcholine induces involuntary smooth muscular contractions. Varying degrees of drying of salivary secretions may occur as well as decreased sweating. Ophthalmic side effects include blurred vision, mydriasis, cycloplegia, and increased ocular tension. Other reported adverse reactions include urinary hesitancy and retention, tachycardia, palpitations, loss of the sense of taste, headache, nervousness, mental confusion, drowsiness, weakness, dizziness, insomnia, nausea, vomiting, constipation, bloated feeling, impotence, suppression of lactation, and allergic reactions or drug idiosyncrasies including anaphylaxis, urticaria and other dermal manifestations.

Dicyclomine is an anticholinergic tertiary amine used frequently by oral and parenteral route as an effective anti-spasmodic agent. Dicyclomine hydrochloride salt is approved under brand name bentyl for the treatment of functional bowel/irritable bowel syndrome. In addition is known, that dicyclomine is also used in morning and motion sickness, dysmenorrheal, intestinal hypermotility. It was shown, that Dicyclomine is a selective M1 and M3 muscarinic receptors antagonist, but os shown pharmacological activity via the M1 receptor.

Berefrine (also known as phenylephrine oxazolidine), a prodrug of phenylephrine, is a mydriatic agent. Berefrine was developed for improving ocular absorption and reducing systemic side effects.