Haloperidol
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Haloperidol (Aloperidin®; Bioperidolo®; Brotopon®; Dozic®; Einalon S®; Eukystol®; Haldol®; Halosten®; Keselan®; Linton®; Peluces®; Serenace®; Serenase®; Sigaperidol®) is a conventional butyrophenone antipsychotic drug. It was developed in 1957 by Belgian company Janssen and submitted to first clinical trials in Belgium in the same year. After being rejected by US company Searle due to side effects it was later marketed in the US by McNeil Laboratories.
The drug is used in the control of the symptoms of acute psychosis, acute schizophrenia manic phases, hyperactivity, and also to control aggression, extreme agitation, and psychotic thinking, which can also be provoked by amphetamines, LSD and PCP abuses.
In low doses it is useful in controlling moods swings and delusional thinking.
It has been used in individuals with personality disorders and to treat Tourette's syndrome, and has been used off label in the treatment of stopping and controlling severe nausea and vomiting caused as a side effect by other drugs such as cancer treatment chemotherapy and sometimes LSD intoxication.
It works by acting on the dopamine receptors in the brain. The drug is classified as a high-potency antipsychotic, which means that it has a smaller dose (in the tens of milligrams or less) and less sedating effects than other antipsychotics such as Chlorpromazine.
The drug is also significant in that it was designed and not discovered through trial and error. Once it became clear that antipsychotics worked by blocking dopamine receptors, Haloperidol was designed by producing a molecule that would do exactly that.
Haloperidol is an odourless white to yellow crystalline powder. Its chemical name is 4-[4-(p-chlorophenyl)-4-hydroxypiperidino]-4'-fluorobutyrophenone and its empirical formula is C21H23ClFNO2
The drug is noted for its strong extrapyramidal side-effects. Common side effects include dry-mouth, lethargy, muscle-stiffness, muscle-cramping, restlessness, tardive dyskinesia, tremors, and weight-gain, although side effects like this are much more likely when the drug is taken many times a day for long periods, sometimes years. The risk of tardive dyskinesia is around 4% in younger patients, higher than in most other antipsychotic drugs - in North America the characteristic gait of patients treated with haloperidol has been nicknamed "The Haldol Shuffle." In patients over the age of 45 the percentage afflicted can be much higher. These symptoms can be permanent, despite discontinuation of the medication. Neuroleptic malignant syndrome (NMS) is a significant possible side effect.
As well as Haloperidol the decanoate ester Haloperidol decanoate (Haldol Decanoate®; Halomonth®; Neoperidole®) can be used or Haloperidol Lactate. The decanoate has a greatly extended duration of effect and its structural formula is 4-(4-chlorophenyl)-1-1[4-(4-fluorophenyl)-4-oxobutyl]-4 piperidinyl decanoate, which looks like:
