Haloperidol dosing

Haloperidol 20 x oral haloperidol daily dose 10-15 x oral haloperidol dose, With initial dosing, oral supplementation... 

Lin, K. M., Poland, R. E. etal. (1989). A longitudinal assessment of haloperidol doses and serum concentrations in Asian and Caucasian schizophrenic patients. Am. J. Psychiatry, 146(10), 1307-11. 

McEvoy JP, Hogarty GE, Steingard S Optimal dose of neuroleptic in acute schizophrenia a controlled study of the neuroleptic threshold and higher haloperidol dose. Arch Gen Psychiatry 48 739—745, 1991... 

Haloperidol is the best-studied antipsychotic medication in children and adolescents with schizophrenia. In a double-blind, placebo- and active-controlled study, haloperidol (2 to 16 mg per day) and loxapine (10 to 200 mg per day) were equally effective and superior to placebo ( 168). This finding was replicated in a placebo-controlled, crossover study of haloperidol (doses of 0.5 to 3.5 mg per day or 0.02 to 0.12 mg/kg per day) in children 5.5 to 12 years of age ( 169). In this study, haloperidol was more effective than placebo in reducing ideas of reference, persecutory ideas, hallucinations, and thought disorder. 

In a randomized, double-blind, 12-week study in 78 inpatients with schizophrenia assigned to either risperidone 6 mg/day (73% men n — 41) or haloperidol 20 mg/day (81% men n = 37), prolactin concentrations increased significantly in men in both groups (1033). Adjusted for haloperidol dose equivalents (risperidone 6 mg/day equivalent to haloperidol 12 mg/day), risperidone caused a significantly larger rise in prolactin than haloperidol. The study was limited by the small number of women in the sample, which allowed the comparison of prolactin concentrations by sex but without consideration of treatment the women had a significantly larger rise in prolactin than the men. 

The effects of haloperidol dose and plasma concentration and CYP2D6 activity on the QTC interval have been studied in 27 Caucasian patients taking oral haloperidol (aged 23-77 years, dosages 1.5-30 mg/day) (9). Three patients had a QTC interval longer than 456 ms, which can be considered as the cut-off value for a risk of cardiac dysrhythmias. There was no correlation between QTC interval and haloperidol dosage or plasma concentrations or CYP2D6 activity. 

The prevalence of hyperprolactinemia in patients with chronic schizophrenia taking long-term haloperidol has been studied in 60 patients in Korea (28 women illness mean duration, 15.5 years) (24). There was hyperprolactinemia, defined as a serum prolactin concentration over 20 ng/ml in men and 24 ng/ml in women, in 40 the prevalence of hyperprolactinemia in women (93%) was significantly higher than in men (47%). There was also a significant correlation between haloperidol dose and serum prolactin concentration in women, but not in men. 

Netazodone may reduce clearance of haloperidol, so haloperidol dose may need to be reduced... 

Avoid use of neuroleptics (except clozapine) in Parkinson s patients Monitor BP in patients reduce dosage of medications as necessary to prevent falls, dizziness Increase haloperidol dose as necessary... 

Adverse effects have been reported with haloperidol doses of 2 mg/day or greater. In one review of 24 patients treated with haloperidol for Tourette s disorder, 66.7% discontinued treatment due to intolerable side effects (e.g., dysphoria, akathisia, nervousness, sedation,... 

On the whole significant interactions between the antipsychotics and SSRIs appear rare (although see thioridazine, below). The combination can be useful and so the isolated cases of extrapyramidal adverse effects should not prevent concurrent use. However, if extrapyramidal effects become troublesome bear this interaction in mind as a possible cause. The significance of the rise in haloperidol levels caused by fluoxetine and fluvoxamine is unclear, be aware that haloperidol adverse effects may be increased in some patients and consider reducing the haloperidol dose if problems occur. The rise in perphenazine levels caused by paroxetine seems to result in a greater number of more serious adverse effects and so consideration should be given to reducing the dose of perphenazine if paroxetine is started. Citalopram may be a suitable alternative as it does not appear to affect perphenazine levels. 

Perry PJ, Miller DD, Arndt SV, Smith DA, Holman TL. Haloperidol dosing requirements the contribution of anckii and nonlinear phmmacckinetics. J CUn Psychopharmacol (1993) 13, 46-51. 

There are few reports on the effects of nitrous oxide on dopaminergic neurotransmission. A study in mice showed that nitrous oxide inhalation produced a significant increase in locomotor activity that was antagonized in a dose-dependent fashion by the dopamine synthesis inhibitor a-methyl-/)-tyrosine (Hynes and Berkowitz 1983). Moreover, administration of the D2 antagonist haloperidol also reduced the locomotor activity induced by nitrous oxide (Hynes and Berkowitz 1983). These results suggest that excitatory effects induced by nitrous oxide may be also mediated by dopaminergic neurotransmission. However, other studies have reported that exposure to nitrous oxide resulted in decreased dopamine release by neurons in the striatum (Balon et al. 2002 Turle et al. 1998). 

Chouinard G, Jones B, Remington G, et al (1993). A Canadian multicentre placebo controlled study of fixed doses of risperidone and haloperidol in the treatment of chronic schizophrenic inpatients./Clin Psychopharmacol25—40. 

Figure 7.5 Rate recording of the dose-dependent inhibitory effects of apomorphine (pg/kg) on the spontaneous activity of a neuron in the medial prefrontal cortex of the halothane anaesthetised rat and its antagonism by haloperidol (HAL, 0.5mg/kg). Time scale is 50 min intervals. Reproduced by permission from Dailey (1992)...

This effect was reversed by haloperidol. On the other hand, lower doses of PCP (and NANM) increased cell firing in both areas in a... 

The administration of low doses of PCP to rodents induces hyperactivity and stereotypy (Chen et al. 1959 ). The observation that neuroleptics such as chlorpromazine, haloperidol, and pimozide, and adrenolytics such as alpha-methyl paratyrosine antagonize these behavioral effects of PCP suggests that they are mediated by facilitation of central dopaminergic neurotransmission (Murray and Horita 1979). The actions of PCP on central dopaminergic neurotransmission may be similar to amphetamine. A dose of PCP (2.5 mg/kg) in rats, which has no effects when given alone, enhances the behavioral effects of 1 and 3 mg/kg of d-amphetamine (Balster and Chait 1978). PCP, like dopamine, has also been shown to suppress plasma prolactin (Bayorh et al. 1983). However, the firm establishment of an excl usive relationship between dopamine neuro-transmission and PCP effects is difficult because of the prominent interactions of this drug with other neurotransmitter systems. 

Haloperidol 2 mg slow IVP, followed by doubling the dose every 15-20 min until desired effect. For maintenance regimen, add up total loading dose and administer 25% every 6 h for a few days. Then taper dose over several days... 

Cocaine or stimulant intoxication may require administration of a small dose of a short-acting benzodiazepine (e.g., lorazepam 1 to 2 mg) for agitation or severe anxiety. Antipsychotics (e.g., haloperidol 2 to 5 mg) should be used only if psychosis is present. If hyperthermia is present, initiate cooling measures. 

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