Haloperidol excretion

Stewart RB, Karas B, Springer PK. Haloperidol excretion in human milk. Am J Psychiatry 1980 137(7) 849-50. 

Uematsu, T., Sato, R., Fujimori, O., and Nakashima, M., Human scalp hair as evidence of individual dosage history of haloperidol a possible linkage of haloperidol excretion into hair with hair pigment. Arch. Dermatol. Res., 282,120,1990. 

Disposition in the Body. Readily absorbed after oral administration bioavailability about 65%. Haloperidol is localised in the tissues and rapidly taken up by the brain. It is slowly excreted in the urine, about 40% of a dose being eliminated in 5 days with only about 1% of the dose as unchanged drug about 15% of a dose is excreted in the bile. Metabolites which have been identified in urine are 4-fluorobenzoylpropionic acid and 4-fluorophenylaceturic acid (the glycine conjugate of 4-fluoro-phenylacetic acid), both of which are inactive. Haloperidol is also metabolised by reduction of the ketone group to a secondary alcohol. 

Haloperidol is readily absorbed from the gastrointestinal tract. Peak plasma levels occur 2 to 6 hours after ingestion. The drug is concentrated in the liver and CNS. Approximately 15% of a given dose is excreted in the bile, and approximately 40% is eliminated through the kidney. Figure 22.8 shows the typical oxidative metabolic pathway of butyrophenones as exemplified by haloperidol (41). 

Imipramine. The urinary excretion ofa test dose of C-imipramine given to two schizophrenie patients was reduced by about 35 to 40% when they took haloperidol 12 to 20 mg daily. The plasma metabolite levels of C-nortriptyline of another schizophrenie fell while taking haloperidol 16 mg daily, whereas plasma levels of unehanged nortriptyline rose. ... 

H.D. Eddington and D. Young Biliary excretion of reduced haloperidol glucuronide, Psychopharmacology (BerL) 1990, 100, 46-48. 

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