Haloperidol

Haloperidol (Haldol, Aloperidine, Keselan, Serenace) is a neurological drug for the treatment of psychotic disorders such as schizophrenia.The daily recommended dose is 0.5 t0 2.0 mg for patients with moderate symptoms and 3.0 to 5.0 mg for those with severe symptoms.

Depending on the medical situation, haloperidol can be administered orally, intramuscularly, or intravenously in a hospital setting. Based on the drug’s pharmacokinetics, if the drug is in the water-soluble form (e.g. lactate, hydrogen chloride), intramuscularly injected haloperidol should be circulating in the bloodstream within 20 minutes (time to peak concentration). Haloperidol has a half-life of 14 to 31 hours according to Baselt,  so blood concentrations are not going to decline quickly once absorption and distribution are complete. However, if the haloperidol is given intramuscularly in the form of an oily depot injection (e.g. decanoate), absorption will be much slower (six days to peak concentration and a half-life of three weeks).

Haloperidol is measured in serum or plasma by liquid chromatography tandem mass spectrometry. Specimen requirement is a red top or green top tube of blood. Published therapeutic ranges range from 5 to17 ng/mL.

References

• Baselt RC. Disposition of Toxic Drugs and Chemicals in Man, 9th ed. Seal Beach, Calif.: Biomedical Publications; 2011.
• Ulrich S, Neuhof S, Braun V, Meyer FP. Therapeutic window of serum haloperidol concentration in acute schizophrenia and schizoaffective disorder. Pharmacopsychiatry. 1998;31(5):163–169.