Procyclidine Hydrochloride

Procyclidine Hydrochloride Chemical formula
Synonyms: (BANM, rINNM) Hidrocloruro de prociclidina; Procyclidine, Chlorhydrate de; Procyclidini Hydrochloridum. 1-Cyclohexyl-1-phenyl-3-(pyrrolidin1-yl)propan-1-ol hydrochloride.
Cyrillic synonym: Проциклидина Гидрохлорид.

💊 Chemical information

Chemical formula: C19H29NO,HCl = 323.9.
CAS — 77-37-2 (procyclidine); 1508-76-5 (procyclidine hydrochloride).
ATC — N04AA04.
ATC Vet — QN04AA04.


In Br. and US.

BP 2008

(Procyclidine Hydrochloride). A white, odourless or almost odourless, crystalline powder. Sparingly soluble in water; soluble in alcohol; practically insoluble in acetone and in ether. A 1% solution in water has a pH of 4.5 to 6.5.

USP 31

(Procyclidine Hydrochloride). A white crystalline powder, having a moderate characteristic odour. Soluble 1 in 35 of water, 1 in 9 of alcohol, 1 in 6 of chloroform, and 1 in 11 000 of ether; insoluble in acetone. pH of a 1% solution in water is between 5.0 and 6.5. Store in a dry place in airtight containers. Protect from light.

💊 Adverse Effects, Treatment, and Precautions

As for Atropine Sulfate. Psychotic episodes may be precipitated in patients with mental disorders when procyclidine is used for the treatment of druginduced extrapyramidal syndrome.


Like other antimuscarinics procyclidine has been abused for its euphoriant effects.1,2
1. McGucken RB, et al. Teenage procyclidine abuse. Lancet 1985; i: 1514
2. Dooris B, Reid C. Feigning dystonia to feed an unusual drug addiction. J Accid Emerg Med 2000; 17: 311.

💊 Interactions

As for antimuscarinics in general. Paroxetine increases plasma-procyclidine concentrations and it is recommended that the dose of procyclidine should be reduced if antimuscarinic effects are seen in patients receiving both drugs.

💊 Pharmacokinetics

Procyclidine hydrochloride is absorbed from the gastrointestinal tract and bioavailability has been reported to be 75% after oral doses; it disappears rapidly from the tissues. Procyclidine given intravenously acts within 5 to 20 minutes and has a duration of effect of up to 4 hours. The mean plasma elimination half-life after oral or intravenous doses is about 12 hours. About onefifth of an oral dose is metabolised in the liver, mainly by the cytochrome P450 isoenzymes, followed by conjugation with glucuronic acid. A small amount of unchanged drug is excreted in the urine.
1. Whiteman PD, et al. Pharmacokinetics and pharmacodynamics of procyclidine in man. Eur J Clin Pharmacol 1985; 28: 73–8.

💊 Uses and Administration

Procyclidine hydrochloride is a tertiary amine antimuscarinic with actions and uses similar to those of trihexyphenidyl. It is used for the symptomatic treatment of parkinsonism, including the alleviation of the extrapyramidal syndrome induced by drugs such as phenothiazines, but, like other antimuscarinics, is of no value against tardive dyskinesias. It has been used in the treatment of dystonias. In parkinsonism, the initial oral dose of 2.5 mg three times daily may be increased gradually by 2.5 to 5 mg every 2 or 3 days (or by 2.5 mg daily if used for druginduced extrapyramidal syndrome) until the optimum maintenance dose, usually 10 to 30 mg daily in 3 (or occasionally 4) divided doses, is reached; daily doses of up to 60 mg have occasionally been required. As a rule, postencephalitic patients tolerate and require the larger doses; elderly and arteriosclerotic patients may require smaller doses. In emergency, 5 to 10 mg may be given by intravenous injection; higher doses have sometimes been used. The intramuscular route has also been employed: 5 to 10 mg may be given as a single injection, repeated if necessary after 20 minutes to a maximum of 20 mg daily. Parenteral doses are usually effective within 5 to 10 minutes but may need 30 minutes to produce relief. Although not licensed in the UK for management of dystonias in children, the BNFC suggests oral doses of 1.25 mg 3 times daily in those aged 7 to 12 years, and 2.5 mg 3 times daily in those aged 12 to 18 years. In an emergency, a single dose may be given by intramuscular or intravenous injection to children as follows: aged under 2 years, 0.5 to 2 mg; 2 to 10 years, 2 to 5 mg; 10 to 18 years, 5 to 10 mg or occasionally more.

💊 Preparations

BP 2008: Procyclidine Injection; Procyclidine Tablets; USP 31: Procyclidine Hydrochloride Tablets.

Proprietary Preparations

Austria: Kemadrin; Belg.: Kemadrin; Canad.: Kemadrin†; Procyclid†; Cz.: Kemadrin; Denm.: Kemadrin; Ger.: Osnervan; Hung.: Kemadrin; India: Kemadrin; Irl.: Kemadrin; Israel: Kemadrin; Ital.: Kemadrin†; Malaysia: Kemadrin†; NZ: Kemadrin; Spain: Kemadren; Switz.: Kemadrin; UK: Arpicolin; Kemadrin; Muscinil†; USA: Kemadrin.
Published November 20, 2018.