User:Mwhitak2/sandbox

Benperidol (sometimes referred to by its old name Anquil) is a drug which is member of the butyrophenone class. It is characterized as an antipsychotic, neuroleptic or wrongly as a major tranquilizer. It is the most potent neuroleptic on the European market, with chlorpromazine equivalency as high as 75 to 100 (about 150 to 200% potency in terms of dose compared to haloperidol). It is an antipsychotic, which can be used for the treatment of schizophrenia, but it is primarily used to control antisocial hypersexual behaviour, and is sometimes prescribed to sex offenders as a condition of their parole, as an alternative to anti-androgen drugs such as cyproterone. Benperidol was first offered in the UK in 1973; where it was popular until the 1980s but overtime its use has declined. It isn’t available in the Republic of Ireland. Benperidol was first synthesized and produced by Janssen Pharmaceutica in 1961. Benperidol in the Anquil tablet form has a shelf life of 60 months. Internationally it is known as: Benperidolum (Latin), Benperidol (German), Benpéridol (French), Benperidol (Spanish). Other brand names include: Anquil- Archimedes Pharma, United Kingdom, Benperidol-Neuraxpharm, Germany, Frenactil-Janssen, Belgium; Janssen, Luxembourg, Glianimon-Bayer Vital, Germany.

Description
Benperidol is prescribed and administered in the form of a pill to be taken orally. The usual prescribed dose is 0.25-1.5mg (250-1500 micrograms) a day for an adult. This is usually split up into 2 or 3 doses throughout the day. The dose prescribed to the elderly (65+) is usually half that of an adult. Doses are determined based on a patient’s age, symptom severity, and previous response to other neuroleptic drugs. Benperidol tablets should be swallowed with at least half a glass of water while either sitting or standing. .

=Pharmacokinetics= Benperidol works by blocking a variety of receptors in the brain, particularly dopamine D2 receptors. It is thought that overstimulation of dopamine receptors may result in mental illness. Benperidol is a potent dopamine receptor antagonist. By binding to the dopamine receptors on the post-synaptic neuron it stops them from generating a stimulus and becoming over stimulated, helping to control mental illness, specifically schizophrenia. It is still not entirely understood why Benperidol also acts as antilibidinous drug as well as an neuroleptic.

Bioavailability
Bioavailabilty of Benperidol is, after intravenous (IV) administration, 3.2 minutes for the distribution half-life, 5.80 hours for the elimination half-life (t1/2ß), 4.21 l/kg for the distribution volume, 7.50 hours for the mean residence time (MRT), and 0.50 l/(h*kg) for clearance in adults. After oral administration as either a liquid or a tablet, the mean-g data for the time lag until the first appearance of measurable plasma concentrations were 0.33 and 1.1 hours respectively, and mean-g tmax, the amount of time that the drug is present at the max amount in the blood, data  were 1.0 hours  and  2.7 hours. Differences between liquid and tablet administration were statistically significant for time lag. Mean-g absolute bioavailabilities were computed as 48.6 %  after liquid and 40.2%  after  tablet  administration. The plasma concentrations of benperidol were found to be very low. Excipients, pharmacologically inactive substances used as carrier for active ingredients of a medication, include lactose and magnesium stearate, which act as fillers, and starch, which holds the ingredients of the pill together.

Clinical Findings
A study administered 2mg tablets of Benperidol to volunteers and the following values were reported: Cmax, the maximum level of the drug in the tested area (typically blood plasma), was 4.1 ± 1.7 μg/l, Tmax 2.9 ± 1.8 h, AUC(0-24) ,(‘area under the curve’ extrapolated to infinity) which can be used to estimate bioavailability, was 39.8 ± 9.4 μg.h/l. After repeated administration of 3 and 12 mg benperidol to patients, plasma levels of 10 and 30 μg/l respectively have been reported.

=Pharmacodynamics= Benperidol is classified as a dopaminergic (D2) receptor anatagonist, because it binds to the receptor in the place of dopamine, preventing the postsynaptic neuron from creating a stimulus. It is also known to have antilibidinous and antipsychotic effects as well. Those taking may be at risk for extrapyramidal side effects, but only if taking larger (greater than .5mg/day) doses. Benperidol is not considered to be addictive. If alcohol is consumed while taking benperidol it may make the consumer feel very sleepy. Consult a doctor before driving or operating machinery.

Treatment
Benperidol is predominantly used to treat schizophrenia and to treat antisocial hypersexual behavior. It does this by actively targeting D2 receptors in many areas of the brain. It is such an effective medication because individuals with schizophrenia are highly sensitive to dopamine. It is also a very successful antilibidinous agent and has been prescribed to inmates during their parole to decrease their sexual urges. In a clinical study (n=54), treatment with Benperidol was successful in reducing the libido in all but 2 of the participants to some extent.

=Side Effects=

Common
More than 1 in 10 people might experience:
 * Sleepiness
 * Movement disorders (extrapyramidal side effects)

Less Common
Less than 1 in 10 people might experience:
 * Hypotension
 * Headache
 * Restlessness
 * Raised Prolactin (hyperprolactinaemia)
 * Constipation

Rare
Less than 1 in 100 people might experience:
 * Blurred vision
 * Weight gain
 * Skin rashes

Unless otherwise instructed by a doctor, avoid suddenly stopping administration of Benperidol. This is because while Benperidol controls the symptoms of mental illness, it doesn’t actually cure mental illness. This means that if treatment is suddenly stopped the symptoms of the illness will reappear. In rare cases patients suffer withdrawal symptoms such as nausea, vomiting, or difficulty sleeping.

Benperidol should be used with caution in :
 * the elderly, especially those with dementia
 * Those with or at risk for:
 * kidney failure
 * liver disease
 * heart disease (for example arrhythmias)
 * disturbances in the normal levels of salts in the blood
 * stroke, or a type of irregular heartbeat called atrial fibrillation
 * epilepsy
 * conditions that increase the risk of epilepsy or convulsions (ex. brain damage or withdrawal from alcohol)

Benperidol should not be used in: children, patients in an unresponsive conscious states (ex. comatose), those with Parkinson’s disease, people with reduced awareness, slow reactions, or drowsiness due to medicines or illness that reduce activity in the central nervous system, people with abnormal body movements (ex. twitching or trembling), those with depression, or tose with rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption (Anquil tablets contain lactose).

Pregnancy and Breast Feeding
The safety of benperidol for use during pregnancy has not been established. It is not recommended for use during pregnancy unless considered essential by a medical physician. This medicine passes into breast milk and may potentially have adverse effects on a nursing infant. Mothers taking benperidol should not breastfeed during treatment.

Interaction with Other Medications
There may be increase risk of drowsiness and sedation if Benperidol is taken with any of the following: alcohol, barbiturates, benzodiazepines, MAOI antidepressants, sedating antihistamines, sleeping tablets, strong opiod painkillers, or tricyclic antidepressants.

Medicines that increase the risk of any type of abnormal heart rhythm, seen as a ‘prolonged QT interval’ on an ECG, should not be taken in combination with benperidol. These include the following :
 * antiarrhythmics
 * the antihistamines astemizole, mizolastine, or terfenadine
 * atomoxetine
 * certain antidepressants (ex, amitriptyline, imipramine, maprotiline)
 * centain antimalarials (ex. halofantrine, chloroquine, quinine, meflogquine, Riamet)
 * certain antipsychotics (ex. thioridazine, haloperidol, chlorpromazine, sertindole)
 * cisapride
 * intervenous 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 (ex. 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). 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.

Alternatives
Benperidol has been compared to haloperidol in its use for treatment of schizophrenics.