Biperiden

With the discontinuation of licensed procyclidine injection, there are no licensed alternatives available within the UK. Biperiden 5 mg/ml solution for injection is an unlicensed medicine indicated for the treatment of extrapyramidal adverse effects induced by neuroleptic drugs particularly if severe or in case of emergency.

Informed consent

Due to its unlicensed status, informed consent and explanation for the rationale of treatment choice must be obtained prior to treatment initiation.¹ Patient information explaining unlicensed medication in general terms is available via the Choice and Medication portal, as is a specific biperiden leaflet.² Where there is a lack of capacity, adherence to the principles contained in the Adults with Incapacity (Scotland) Act, 2000 is mandatory.

Due to the emergency nature of this treatment, consent may not always be possible, if consent is not obtained then this should be documented within the patient’s electronic record.

Documentation

The consultant psychiatrist must make a clear record of the rationale for prescribing an unlicensed medication within the patient’s case notes and document the discussion regarding consent.¹ Due to the emergency nature of treatment, this may occur after administration.

Nursing staff in the ward must be informed of the medicine’s unlicensed status by the prescriber and ward clinical pharmacists must ensure that staff are aware of the unlicensed status.

When ordering biperiden, the phrase “as per protocol” should be included on the requisition for the order to be processed.

A record of administration of unlicensed medication must be kept (as per unlicensed medication policy).³

This should be entered on the patients electronic record and must include the drug batch number and expiry date. Failure to do this will be in breach of unlicensed medicines procedure. It is the responsibility of the nurse in charge to ensure this occurs.

When supplying biperiden from pharmacy, pharmacy staff must ensure that batch numbers and expiry dates are documented on the requisition.

There is no requirement for any specific monitoring.

Adults:

2.5–5 mg as a single dose by intramuscularly injection.

If necessary, the same dose can be injected again after 30 minutes.

The maximum daily dose is 10–20 mg

Children up to 1 year: 1 mg as single dose

Children up to 6 years: 2 mg as a single dose

Children up to 10 years: 3 mg as a single dose

Rare (may affect up to 1 person in 1,000)

• At high doses: excitement, agitation, confusion, fear, delirium, hallucinations, sleep disturbances
• fatigue, dizziness
• memory disturbances
• tachycardia
• dry mouth, nausea, stomach problems
• drowsiness

Very rare (may affect up to 1 person in 10,000)

• Hypersensitivity
• nervousness, euphoria
• headache
• abnormal involuntary movements (dyskinesia), loss of muscle coordination (ataxia), difficulty speaking, increased likelihood of having epileptic fits and convulsions
• visual disturbances (e.g. difficulty focusing), dilation of pupils (mydriasis), sensitivity to light (photosensitivity), increased pressure in the eye (glaucoma)
• decreased heartbeat
• drop in blood pressure (following administration by injection)
• constipation
• reduced sweating, allergic rash
• contraction of the muscles
• difficulty emptying the bladder (in particular in patients with a prostate tumour), urinary retention.

Contraindications⁶

• Allergy to the active substance or any of the other ingredients of this medicine
• Glaucoma
• Mechanical stenosis of the gastrointestinal tract or intestinal atony
• Malformation of the colon, characterised by excessive dilation of this organ (megacolon);
• Urinary retention

Cautions⁶

• Recent heart attack or heart rate abnormalities
• Prostate disorder characterised by swelling of this organ (prostatic hypertrophy),
• Tendency towards seizures
• Myasthenia gravis
• Pregnancy and breastfeeding

Interactions^5,6

• Abuse and dependence on biperiden have been observed in isolated cases. This could be related to the occasionally observed mood elevation and unnaturally elevated mood.
• Alcohol can increase the sedative effects of biperiden.
• The effects of anticholinergics may be enhanced by use with other drugs having anticholinergic properties, such as amantadine, some antihistamines, phenothiazine antipsychotics, and tricyclic antidepressants.
• Inhibition of drug-metabolising enzymes by MAOIs may possibly enhance the effects of anticholinergics.
• The reduction in gastric motility caused by anticholinergics may affect the absorption of other drugs.
• Anticholinergics may also antagonise the gastrointestinal effects of cisapride, domperidone, and metoclopramide.
• Anticholinergics and parasympathomimetics may counteract each other’s effects.

1. GMC Good practice in prescribing and managing medicines and devices. Updated December 2024 http://www.gmc-uk.org/guidance/ethical_guidance/14316.asp
2. Choice and Medication. Handy Fact Sheets. Unlicensed medications and biperiden PIL http://www.choiceandmedication.org/nhs24/
3. NHS Greater Glasgow and Clyde Area Drug and Therapeutics Committee Policies Relating to the Management of Medicines Section 9.15-7-unlicensed-medicines-policy-dec-25.doc
4. Taylor D, Paton C, Kapur S. The Maudsley Prescribing Guidelines in Psychiatry; 13th edition: Wiley Blackwell
5. Martindale. The Complete Drug Reference. https://www.medicinescomplete.com/mc/martindale/2009/ Accessed 24/2/2026.
6. Prescribing Information. Biperiden 5mg/ml, 1 ml ampoules, solution for injection (Akineton). Laboratorio Farmaceutico SIT. Nov 2015 (obtained from Mawdsleys Brooks & Co)