Biperiden (Akineton): Uses, Side Effects, and Availability

Biperiden (brand name Akineton) is an anticholinergic medicine used to reduce the stiffness and tremor of parkinsonism and to control the movement side effects that some antipsychotic drugs cause. It works by blocking acetylcholine, a chemical messenger in the brain that becomes relatively overactive when dopamine is low. The FDA-approved labeling described it as an adjunct in all forms of parkinsonism and for control of extrapyramidal disorders secondary to neuroleptic (antipsychotic) drug therapy.

One point up front: the Akineton brand name and all generics have been discontinued in the United States. Biperiden is still available in other countries, including as tablets and prolonged-release tablets in parts of Europe. This guide explains what biperiden is, how it works, what it was used for, typical dosing, side effects (many of them “atropine-like”), who should avoid it, what to know about anticholinergic burden in older adults, interactions, and the alternatives used today. It also replaces our separate page on Akineton.

This is general information based on FDA-era labeling, drug references, and published research, not medical advice. If you take biperiden or a similar medicine, never stop it suddenly, and ask your prescriber about the best plan for you.

Biperiden at a glance

Drug class	Anticholinergic (antimuscarinic) antiparkinson agent
Brand name	Akineton
US availability	Brand and generics discontinued; still available in other countries
Uses	Parkinsonism (adjunct); movement side effects from antipsychotics (extrapyramidal reactions)
Forms	2 mg tablets; prolonged-release 4 mg tablets and injection in some countries
Typical adult oral dose (US label era)	Parkinsonism: 2 mg three to four times daily, maximum 16 mg per day. Drug-induced movement problems: 2 mg one to three times daily
Common side effects	Dry mouth, blurred vision, constipation, urinary retention, drowsiness, confusion
Do not use in	Narrow-angle glaucoma, bowel obstruction, megacolon, hypersensitivity

What biperiden is and how it works

Movement control in the brain depends on a balance between two chemical messengers in a region called the corpus striatum. Dopamine is inhibitory in this balance and acetylcholine is excitatory. In Parkinson’s disease, dopamine-producing cells are lost, so acetylcholine’s effects become relatively too strong, which contributes to tremor, stiffness, and slowed movement. Antipsychotic medicines that block dopamine can cause a similar imbalance and produce parkinson-like side effects.

Brain diagram showing biperiden blocking acetylcholine in the striatum

Biperiden is a muscarinic receptor antagonist. Drug databases describe its main target as the M1 muscarinic receptor, and its mechanism is considered to be competitive blocking of acetylcholine at cholinergic receptors in the corpus striatum, which then helps restore the balance. It acts in both the central and peripheral nervous systems, which explains both its benefits and its side effects: blocking acetylcholine in the body causes dry mouth, constipation, and other “anticholinergic” effects.

What biperiden was approved to treat

Parkinsonism

The Akineton labeling described it as an adjunct in the therapy of all forms of parkinsonism: idiopathic (Parkinson’s disease), postencephalitic, and arteriosclerotic. A drug monograph adds that it was more efficacious in postencephalitic and idiopathic cases than in arteriosclerotic types. It relieves muscle rigidity, reduces sweating and salivation, improves gait, and, to a lesser extent, tremor.

Anticholinergics are a small part of Parkinson’s care today. They mostly help tremor and drooling and are used less than dopamine-based medicines because of their effects on thinking and memory (see below).

Drug-induced extrapyramidal reactions

Antipsychotics (neuroleptics), especially older ones such as phenothiazines and haloperidol, can cause movement problems called extrapyramidal symptoms. These include:

Parkinsonism (stiffness, tremor, slowed movement)
Akathisia (inner restlessness with an urge to move)
Acute dystonia (sudden painful muscle spasms, including neck twisting, or eyes rolling upward, called oculogyric crisis)
Dyskinetic tremors and profuse sweating

The labeling for the injectable form described it as an effective agent for acute episodes of these disturbances, reducing or eliminating akathisia, akinesia, dyskinetic tremors, rigor, oculogyric crisis, spasmodic torticollis, and sweating, and said oral doses could then maintain control while antipsychotic treatment continued. Modern antipsychotics cause fewer of these effects, but they still occur. See our comparisons of Risperdal vs Abilify and Abilify vs Seroquel for how different antipsychotics compare on movement side effects.

Parkinsonism vs Parkinson’s disease

The words are close, and biperiden’s label uses “parkinsonism” for a reason.

Parkinson’s disease is a specific progressive condition in which dopamine-producing cells in the brain are lost, causing tremor, stiffness, slowness, and balance problems.
Parkinsonism is a broader term for any condition with those same features. It includes Parkinson’s disease, but also parkinsonism caused by medicines (especially antipsychotics and some anti-nausea drugs), by certain strokes or other brain disease, and by rarer conditions.

This matters because drug-induced parkinsonism often improves once the offending medicine is lowered or changed, while Parkinson’s disease needs ongoing treatment. If new stiffness, tremor, or slowness appears after starting a medicine, tell the prescriber. Do not stop an antipsychotic or another important medicine on your own, since stopping suddenly can cause relapse or withdrawal problems.

Living with drug-induced movement problems

Extrapyramidal side effects can be frightening, especially a sudden muscle spasm of the neck, jaw, or eyes. Some practical points:

Acute dystonia is an emergency-type reaction. A sudden twisting of the neck, tongue protrusion, jaw spasm, or eyes rolling upward after starting or raising an antipsychotic dose needs prompt medical attention. It is usually treatable quickly.
Akathisia can be mistaken for anxiety. The inner restlessness and urge to move can look like agitation. Describe the feeling of not being able to sit still, since it changes treatment.
Tardive dyskinesia is a different problem. Involuntary movements of the mouth, tongue, or limbs that appear after months or years on antipsychotics are managed differently. Anticholinergics such as biperiden can sometimes make them worse, so do not assume every abnormal movement is helped by these drugs.
Regular checks matter. People on antipsychotics should have periodic movement examinations.
Tell everyone involved in your care about the medicines you take, including a psychiatrist, a neurologist, and a pharmacist.
Do not add anticholinergics on your own or take someone else’s supply.

Families of someone taking antipsychotics can help by noting changes in walking, posture, facial expression, handwriting, drooling, or restlessness, and by sharing them with the care team.

Availability today

The FDA’s records show that Akineton injection has not been manufactured since February 1989, and the last batch expired in 1994. Drug reference sources now list the brand and any US generics as discontinued, and one drug guide labels it “off-market” in the United States. Biperiden remains in use in other parts of the world. For example, an Irish product summary describes Akineton Retard 4 mg prolonged-release tablets for adults with parkinsonian syndromes and for extrapyramidal symptoms such as early dyskinesia, akathisia, and parkinsonism provoked by neuroleptics.

If you have been prescribed biperiden abroad or you are reading about it for a family member, ask the prescriber and pharmacist about local products, since strengths and forms differ by country.

Dosing

Dosing is individualized and started low. What follows comes from the US-era labeling and drug references, and European labeling differs in form and range, so use it to follow a conversation with your prescriber, not to set a dose.

Use	Typical oral dosing (US-era references)
Parkinsonism	Initially 2 mg three to four times daily; titrated up to a maximum of 16 mg daily in 3 to 4 divided doses
Drug-induced extrapyramidal reactions	2 mg one to three times daily (usual starting dose is often 2 mg daily)
Acute drug-induced reactions (injection, where available)	2 mg IM or slow IV, repeated every 30 minutes as needed, not exceeding 8 mg in 24 hours
European prolonged-release tablets	Average 4 to 8 mg daily, up to 12 mg daily, taken whole, with or right after meals

Timing and effects: after an oral dose, effects begin in about an hour and last roughly 6 to 12 hours. Doses are usually spread through the day, with the first taken in the morning.

Never stop suddenly. Abruptly stopping an anticholinergic can cause a rebound of movement symptoms or other withdrawal effects. Tapering is directed by the prescriber.

Side effects

Many side effects reflect blockage of acetylcholine throughout the body. The FDA-approved labeling listed atropine-like effects such as:

Dry mouth
Blurred vision
Drowsiness
Euphoria or disorientation
Urinary retention (difficulty passing urine)
Postural hypotension (dizziness on standing)
Constipation
Agitation and disturbed behavior

Other reported effects include:

Reduced REM sleep. The labeling notes a reduction in REM sleep, characterized by increased REM latency and a lower percentage of REM sleep.
Movement problems in combination therapy. A case of generalized choreic movements was reported in a Parkinson’s patient when biperiden was added to carbidopa/levodopa.
Heat intolerance. Because anticholinergics reduce sweating, people can overheat in hot weather or during exercise, so stay cool and hydrated (a general anticholinergic effect).
Fast heart rate and palpitations, and difficulty urinating in men with prostate enlargement.
Large or toxic doses, or usual doses in susceptible patients, can cause marked confusion, hallucinations, agitation, and other central effects.

Tell your prescriber about any confusion, hallucinations, trouble urinating, severe constipation, eye pain, or a very fast heartbeat.

Who should not take biperiden

The US labeling lists these contraindications:

Known hypersensitivity to biperiden
Narrow-angle (angle-closure) glaucoma, since anticholinergics can raise eye pressure
Bowel obstruction
Megacolon

The European product summary adds mechanical stenosis in the gastrointestinal tract, paralytic ileus, prostatic adenoma, and conditions that can lead to dangerous tachycardia.

Use with caution in people with prostatic hyperplasia, heart rhythm problems, or seizure disorders. Biperiden is also listed as Pregnancy Category C in US references, so ask your doctor about risks before or during pregnancy.

Anticholinergic burden and thinking

This is one of the most important safety issues with anticholinergic drugs, especially in older adults.

They affect memory and thinking. Blocking acetylcholine in the brain can cause confusion, memory problems, and delirium. Reviews of trihexyphenidyl, biperiden, and other anticholinergics note their use is limited because of these effects.
Anticholinergic burden may raise dementia risk. A published review notes that cumulative anticholinergic burden can cause a long-term adverse effect of increased risk for developing dementia.
Older adults are more vulnerable. They are more likely to develop confusion, falls, constipation, and urinary retention. Doctors generally avoid or minimize anticholinergics in people with dementia or cognitive impairment.
Add-ons add up. Many other medicines have anticholinergic effects, including some antihistamines, bladder medicines, antidepressants, and antipsychotics. Together, they add to the burden. Our guide to Benadryl and alcohol discusses one common anticholinergic antihistamine.

If you or a relative takes biperiden long term, ask regularly whether it is still needed, whether the dose can be lowered, and whether alternatives exist.

Interactions

Biperiden’s effects can add to or be changed by other medicines. Drug references list these key ones:

Other anticholinergics, antihistamines, antiparkinson drugs, and antispasmodics. Combining them can cause excessive anticholinergic effects, including confusion and overheating. The European summary warns specifically about combinations with other anticholinergic psychotropic drugs, antihistamines, antiparkinsonian drugs, and antispasmodics.
Amantadine. Can increase anticholinergic effects such as confusion and hallucinations, so the biperiden dose may need lowering.
Phenothiazines and other antipsychotics. May increase anticholinergic side effects, and biperiden may reduce the effectiveness of some antipsychotics.
Antacids and antidiarrheals. Can decrease absorption. Take biperiden at least an hour before them.
CNS depressants. Can increase sedation. This includes sedatives, sleeping pills, and alcohol, so avoid or limit alcohol.
Digoxin. May raise digoxin levels. Monitor.
Levodopa. Biperiden may be added to it, but one case of choreic movements has been reported.

Tell your prescriber and pharmacist about all prescription and over-the-counter medicines and supplements.

Biperiden compared with other options

	Biperiden	Trihexyphenidyl (Artane)	Benztropine (Cogentin)
Class	Anticholinergic	Anticholinergic	Anticholinergic
Availability in US	Discontinued	Still used	Still used
Main uses	Parkinsonism, drug-induced movement problems	Same	Same
Main drawbacks	Confusion, dry mouth, urinary retention	Similar anticholinergic effects	Similar anticholinergic effects

Because biperiden is not available in the US, a US prescriber would typically consider other anticholinergics such as benztropine or trihexyphenidyl for drug-induced movement problems. Other strategies include lowering the antipsychotic dose, switching to an antipsychotic with fewer movement effects, and, for akathisia, other medicines. For Parkinson’s disease itself, modern treatment centers on levodopa, dopamine agonists, MAO-B inhibitors, and other medicines, with anticholinergics reserved for select cases, mostly younger patients with prominent tremor.

Whether another drug is appropriate depends on the diagnosis, age, other conditions, and the medicine causing the problem. Ask your neurologist or psychiatrist.

Misuse and safety

Anticholinergics such as biperiden and trihexyphenidyl can produce euphoria or a sense of disorientation at higher doses, and the labeling lists euphoria among side effects. Some people misuse them. Take only as prescribed, never share it, and store it safely. Overdose can cause a dangerous “anticholinergic toxidrome” with fast heart rate, high temperature, dry flushed skin, dilated pupils, confusion, hallucinations, urinary retention, and seizures. Seek emergency care immediately.

Practical tips

Take it as prescribed, with or right after meals if it upsets your stomach, and spread doses through the day.
Manage dry mouth. Sip water, chew sugar-free gum, and see your dentist regularly, since dry mouth raises the risk of cavities.
Prevent constipation. Eat fiber, drink fluids, and stay active. Report severe constipation or belly swelling.
Watch for trouble urinating, especially if you have an enlarged prostate.
Stand up slowly to avoid dizziness.
Avoid overheating. Dress lightly and drink fluids in hot weather.
Protect your eyes. Report eye pain, halos around lights, or sudden blurred vision urgently, since they can signal glaucoma.
Be careful driving until you know how it affects you.
Limit or avoid alcohol and other sedatives.
Do not stop suddenly. Ask about tapering.
Review the medicine regularly with your prescriber.

Questions to ask your prescriber

Why is an anticholinergic the right choice for me or my family member?
Is there an alternative that is easier on thinking and memory?
Could the antipsychotic dose be adjusted instead?
How long will treatment last, and how will we stop it?
Which of my other medicines add anticholinergic effects?
What symptoms should make me call right away?
Since biperiden is not available in my country or region, what is the equivalent?

Frequently asked questions

What is biperiden used for?

To treat stiffness, tremor, and other symptoms of parkinsonism, and to control movement side effects caused by antipsychotic medicines.

Is Akineton the same as biperiden?

Yes. Akineton is the brand name of biperiden.

Is biperiden available in the United States?

The Akineton brand and all US generics have been discontinued. It is still available in some other countries. A US prescriber would typically consider similar anticholinergics such as benztropine or trihexyphenidyl.

What are the side effects of biperiden?

Dry mouth, blurred vision, constipation, urinary retention, drowsiness, dizziness on standing, confusion or disorientation, agitation, and reduced REM sleep. Overheating can occur.

Can biperiden cause memory problems?

Yes. Anticholinergics can impair memory and thinking and may increase dementia risk with long-term high burden, especially in older adults.

Who should not take biperiden?

People with narrow-angle glaucoma, bowel obstruction, or megacolon, or those hypersensitive to it. Use caution with prostate enlargement, heart rhythm problems, and seizures.

Can I drink alcohol on biperiden?

It is best to avoid or limit alcohol, since CNS depressants can increase sedation.

How long does biperiden last?

Effects begin in about an hour and last roughly 6 to 12 hours after an oral dose.

Can I stop biperiden suddenly?

No. Stopping abruptly can cause a rebound of symptoms. Ask your prescriber about a gradual taper.