Haldol is available in sterile vials containing 5 mg strength Haldol per 1 ml of fluid used for injection. Usual starting dose is -5 mg intramuscularly. Dose may vary according to patient response to the drug. Switch to an oral form of this drug is recommended as soon as possible. Haldol may interact with other drugs so the patient needs close observation or monitoring to determine if other side effects develop. Haldol should only be used during pregnancy or in women likely to become pregnant only if the benefit clearly justifies a potential risk to the fetus; fetal abnormalities and fetal exposure to Haldol in the third trimester have shown dependence at birth. Women who are breastfeeding should not take Haldol because the drug may affect the infant. Although reports of use for behavior modification exist, the drug is not approved for use in children.
The influence of renal impairment on the pharmacokinetics of haloperidol has not been evaluated. About one-third of a haloperidol dose is excreted in urine, mostly as metabolites. Less than 3% of administered haloperidol is eliminated unchanged in the urine. Haloperidol metabolites are not considered to make a significant contribution to its activity, although for the reduced metabolite of haloperidol, back-conversion to haloperidol cannot be fully ruled out. Even though impairment of renal function is not expected to affect haloperidol elimination to a clinically relevant extent, caution is advised in patients with renal impairment, and especially those with severe impairment, due to the long half-life of haloperidol and its reduced metabolite, and the possibility of accumulation (see section ).
CNS depression potentiated with alcohol, other CNS depressants. Possible neurotoxicity with lithium: monitor, discontinue if occurs. Caution with drugs that prolong the QT interval (eg, ketoconazole, paroxetine). May be potentiated by CYP3A4 or CYP2D6 inhibitors/substrates (eg, itraconazole, nefazodone, buspirone, venlafaxine, alprazolam, fluvoxamine, quinidine, fluoxetine, sertraline, chlorpromazine, promethazine. May be antagonized by CYP3A4 inducers (eg, rifampin, carbamazepine); monitor and adjust doses. May increase intraocular pressure with anticholinergics, antiparkinson agents. Monitor anticoagulants.