Anquil (Benperidol)

How does it work?

Anquil tablets contain the active ingredient benperidol, which is a type of medicines called an antipsychotic. (NB. Benperidol is also available without a brand name, ie as the generic medicine.)

Benperidol is sometimes described as a neuroleptic or a 'major tranquilliser', though this last term is fairly misleading, as this type of medicine is not just a tranquilliser, and any tranquillising effect is not as important as the main way it works in psychiatric illness.

Benperidol works by blocking a variety of receptors in the brain, particularly dopamine receptors. Dopamine is a natural compound called a neurotransmitter, and is involved in transmitting messages between brain cells. Dopamine is a neurotransmitter known to be involved in regulating mood and behaviour, amongst other things. It is thought that over-stimulation of dopamine receptors may result in mental illness.

Benperidol blocks dopamine receptors and stops them becoming over-stimulated, which helps to control mental illness.

Benperidol is used to control disturbing, socially unacceptable, sexual behaviour that is caused by mental illness.

What is it used for?

  • Control of disturbing, socially unacceptable, sexual behaviour that is caused by mental illness.

Warning!

  • This medicine may cause drowsiness. If affected do not drive or operate machinery. Alcohol should be avoided.
  • Unless your doctor tells you otherwise, you should not suddenly stop taking this medicine, even if you feel better and think you don't need it any more. This is because the medicine controls the symptoms of mental illness but doesn't actually cure it. This means that if you suddenly stop treatment your illness could come back. Stopping the medicine suddenly may also rarely cause withdrawal symptoms such as nausea, vomiting or difficulty sleeping. When treatment with this medicine is stopped, it should usually be done gradually, following the instructions given by your doctor.
  • Your doctor may want to check your heart function with an ECG before you start treatment with this medicine, and may want to do further checks from time to time throughout your treatment.
  • Your doctor may want you to have regular blood tests to monitor your liver function and blood cells if you are having treatment with this medicine for long periods of time.
  • Consult your doctor immediately if you experience abnormal movements, particularly of the face, lips, jaw and tongue, while taking this medicine. These symptoms may be indicative of a side effect known as tardive dyskinesia, and your doctor may ask you to stop taking this medicine, or decrease your dose.
  • Consult your doctor immediately if you experience the following symptoms while taking this medicine: high fever, sweating, muscle stiffness, faster breathing and drowsiness or sleepiness. These symptoms may be due to a rare side effect known as the neuroleptic malignant syndrome, and your treatment may need to be stopped.

Use with caution in

  • Elderly people.
  • Liver disease.
  • Kidney failure.
  • Heart disease, such as irregular heartbeats (arrhythmias).
  • People with a family history of sudden death due to a heart problem, or a type of abnormal heart rhythm seen on a heart monitoring trace (ECG) as a 'prolonged QT interval'.
  • People with disturbances in the normal levels of salts (electrolytes) in their blood, for example low magnesium or calcium levels.
  • Elderly people with dementia (antipsychotic medicines have been shown to increase the risk of stroke in this group of patients).
  • People with risk factors for having a stroke, for example a history of stroke or mini-stroke (TIA), smoking, diabetes, high blood pressure, or a type of irregular heartbeat called atrial fibrillation.
  • Epilepsy.
  • People with conditions that increase the risk of epilepsy or convulsions, eg brain damage or withdrawal from alcohol.

Not to be used in

  • Children.
  • Unresponsive unconscious states (comatose states).
  • People with reduced awareness, slow reactions or drowsiness due to medicines or illness that reduce activity in the central nervous system.
  • Parkinson's disease.
  • People with abnormal body movements, for example twitching, muscle stiffness, trembling or restlessness.
  • Depression.
  • Rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption (Anquil tablets contain lactose).

This medicine should not be used if you are allergic to one or any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy.If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.

Pregnancy and breastfeeding

Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.

  • The safety of benperidol for use during pregnancy has not been established. It is not recommended for use during pregnancy unless considered essential by your doctor. Seek medical advice from your doctor.
  • This medicine passes into breast milk and may potentially have adverse effects on a nursing infant. Mothers who need to take this medicine should not breastfeed during treatment. Seek further medical advice from your doctor.

Label warnings

  • This medication may cause drowsiness. If affected do not drive or operate machinery. Avoid alcoholic drink.

Side effects

Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine. Just because a side effect is stated here does not mean that all people using this medicine will experience that or any side effect.

  • Abnormal movements of the hands, legs, face, neck and tongue, eg tremor, twitching, rigidity, slow movements (extrapyramidal effects).
  • Anxiety, restlessness and agitation (akathisia).
  • Rhythmical involuntary movement of the tongue, face, mouth and jaw, which may sometimes be accompanied by involuntary movements of the arms and legs (tardive dyskinesia - see warning section above).
  • Increased salivation.
  • Feeling mentally dulled or slowed down.
  • Headache.
  • Dizziness.
  • Drowsiness.
  • Difficulty sleeping (insomnia).
  • Disturbances of the gut such as constipation, nausea, vomiting or indigestion.
  • Loss of appetite.
  • High blood prolactin (milk producing hormone) level (hyperprolactinaemia). Sometimes this can lead to symptoms such as breast enlargement, production of milk and stopping of menstrual periods.
  • Faster than normal heart beat (tachycardia).
  • Abnormal heart beats (arrhythmias).
  • Low blood pressure (hypotension).
  • Skin rashes.
  • Abnormal liver function or jaundice.
  • Disturbances in the normal numbers of blood cells in the blood.
  • Confusion.
  • Depression.
  • Seizures.
  • High temperature combined with falling levels of consciousness, paleness, sweating and a fast heart beat (neuroleptic malignant syndrome). Requires stopping the medicine and immediate medical treatment - see warning section above.
  • Uncontrolled rolling of the eyes and neck (oculogyric crisis). Requires immediate treatment.

The side effects listed above may not include all of the side effects reported by the medicine's manufacturer.For more information about any other possible risks associated with this medicine, please read the information provided with the medicine or consult your doctor or pharmacist.

How can this medicine affect other medicines?

It is important to tell your doctor or pharmacist what medicines you are already taking, including those bought without a prescription and herbal medicines, before you start treatment with this medicine. Similarly, check with your doctor or pharmacist before taking any new medicines while taking this one, to ensure that the combination is safe.

There may be an increased risk of drowsiness and sedation if benperidol is taken with any of the following (which can also cause drowsiness):

  • alcohol
  • barbiturates, eg amobarbital, phenobarbital
  • benzodiazepines, eg diazepam, temazepam
  • MAOI antidepressants, eg phenelzine
  • sedating antihistamines, eg chlorphenamine, hydroxyzine
  • sleeping tablets, eg zopiclone
  • strong opioid painkillers, eg morphine, codeine, dihydrocodeine
  • tricyclic antidepressants, eg amitriptyline.

Medicines that increase the risk of a type of abnormal heart rhythm, seen as a 'prolonged QT interval' on an ECG, should not be taken in combination with benperidol. These medicines include the following:

  • antiarrhythmics (medicines to treat abnormal heart beats), eg amiodarone, procainamide, disopyramide, sotalol
  • the antihistamines astemizole, mizolastine or terfenadine
  • atomoxetine
  • certain antidepressants, eg amitriptyline, imipramine, maprotiline
  • certain antimalarials, eg halofantrine, chloroquine, quinine, mefloquine, Riamet
  • certain other antipsychotics, eg thioridazine, haloperidol, chlorpromazine, sertindole
  • cisapride
  • intravenous erythromycin or pentamidine
  • moxifloxacin.

There may also be an increased risk of a prolonged QT interval if medicines that can alter the levels of salts such as potassium or magnesium in the blood, eg diuretics such as furosemide, are taken in combination with benperidol.

This medicine may enhance the blood pressure-lowering effects of certain medicines used to treat high blood pressure (antihypertensives). If you are taking medicines for high blood pressure you should tell your doctor if you feel dizzy or faint after starting treatment with this medicine, as your blood pressure medicines may need adjusting.

Benperidol may oppose the effect of levodopa and medicines for Parkinson's disease that work by stimulating dopamine receptors in the brain, for example ropinirole, pergolide, bromocriptine.

Benperidol may oppose the effect of anticonvulsant medicines used to treat epilepsy.

There may be an increased chance of abnormal muscle movements (extrapyramidal side effects) if the following medicines are taken with benperidol:

  • amantadine
  • lithium
  • metoclopramide
  • tetrabenazine.

Other medicines containing the same active ingredient

Benperidol tablets are also available without a brand name, ie as the generic medicine.