Procyclidine

Not to be confused with Phencyclidine.

Procyclidine

Names
IUPAC name 1-cyclohexyl-1-phenyl-3-pyrrolidin-1-yl-propan-1-ol hydrochloride
Clinical data
Drug class	Anticholinergic
Main uses	Parkinsonism, extrapyramidal symptoms due to antipsychotics
Side effects	Dry mouth, blurry vision, nausea, constipation, lightheadedness
Routes of use	By mouth, im, iv
External links
AHFS/Drugs.com	Monograph
MedlinePlus	a605037
Pharmacokinetics
Protein binding	~100%-albumin
Elimination half-life	~12 h
Chemical and physical data
Formula	C19H30ClNO
Molar mass	323.90 g·mol−1

Procyclidine, sold under the brand name Kemadrin among others, is a medication used to treat parkinsonism and extrapyramidal symptoms due to antipsychotics. It improves tremors less than it improves rigidity. It is taken by mouth or by injection into a vein or muscle.

Common side effects include dry mouth, blurry vision, nausea, constipation, and lightheadedness. Other side effects may include a fast heart rate, low blood pressure, urinary retention, confusion, and glaucoma. Safety in pregnancy is unclear. It is an anticholinergic.

Procyclidine was approved for medical use in the United States in 1955. It is available as a generic medication. In the United Kingdom 100 tablets of 5 mg costs the NHS about £5 as of 2021. It is no longer commercially available in the United States as of 2008.

Medical uses

It is used in patients with parkinsonism and akathisia, and to reduce the side effects of antipsychotic treatment given for schizophrenia. Procyclidine is also a second-line drug for the treatment of Parkinson's disease. It improves tremor but not rigidity or bradykinesia.

Procyclidine is also sometimes used for the treatment of dystonia (but not tardive dyskinesia), a rare disorder that causes abnormal muscle contraction, resulting in twisting postures of limbs, trunk, or face.

Dosage

It is generally started at 2.5 mg three times per day by mouth and may be increased to 5 mg four times per day.

Side effects

Side effects include nausea, constipation, urinary retention, blurred vision, anxiety, cognitive impairment, confusion, dizziness, gingivitis, hallucination, memory loss, rash and vomiting.

Overdose

Signs of procyclidine overdose are those of an anticholinergic and include confusion, agitation and sleeplessness that can last up to or more than 24 hours. Pupils become dilated and unreactive to light. Tachycardia (fast heart beat), as well as auditory and visual hallucinations have also been reported.

Other known symptoms of overdose are: clumsiness or unsteadiness, being severely drowsy, having a severely dry mouth, nose, or throat, having an altered mood or other mental changes, seizures, being short of breath or having troubled breathing, a dry and warm, flushed skin.

A suspected overdose with severe life-threatening symptoms should immediately be brought to medical attention, where reversal can be attempted with physostigmine administered intravenously or subcutaneously.

Synthesis

Procyclidine synthesis: DE 1084734  U.S. Patent 2,826,590

Procyclidine, 1-cyclohexyl-1-phenyl-3-pyrrolidinopropan-1-ol, is synthesized in exactly the same manner as was seen for trihexyphenidyl, except this time the linear synthesis begins with the preparation of 3-(1-pyrrolidino)propiophenone.

Procyclidine synthesis 2

In an interesting variation, the ketone is first reacted with phenylmagnesium bromide. Catalytic hydrogenation of the carbinol thus obtained can be stopped after the reduction of only one aromatic ring.

See also

• Biperiden
• Cycrimine

External links

Identifiers:	ATC code: N04AA04 (WHO) CAS Number: 77-37-2 77-37-2 (free base) PubChem CID: 207841 DrugBank: DB00387 ChemSpider: 4750 UNII: C6QE1Q1TKR ChEMBL: ChEMBL1761 Y

• British National Formulary (45 ed.). March 2003.