The intravenous route is not FDA approved and is generally not recommended except when no other alternatives are available. Intravenous administration appears to be associated with a higher risk of QT prolongation and torsade de pointes (TdP) than other forms of administration. The manufacturer recommends ECG monitoring for QT prolongation and arrhythmias if IV administration is required. A dose in the range of 1 to 5 mg IV has been suggested, with the dose being repeated at 30 to 60 minute intervals, if needed. A maximum IV dose has not been established. The lowest effective dose should be used in conjunction with conversion to oral therapy as soon as possible.
3 to 12 years and 15 to 40 kg :
-Initial dose: mg/day orally in 2 to 3 divided doses
-Maintenance dose: to mg/kg/day
-The daily dose may be increased every 5 to 7 days in mg increments.
-There is little evidence that behavior improvement is further enhanced by doses greater than 6 mg/day.
-Limitation of use: Treatment should be reserved for patients with severe behavior problems and/or hyperactive children only after failure to respond to psychotherapy or medications (other than antipsychotics).
-Treatment of severe behavior problems in children, including combative, explosive hyperexcitability not accounted for by immediate provocation
-Short-term treatment of hyperactive children with excessive motor activity and accompanying conduct disorder with impulsivity, difficulty sustaining attention, aggressiveness, mood lability, and/or poor frustration tolerance.
Haloperidol is a typical butyrophenone type antipsychotic that exhibits high affinity dopamine D 2 receptor antagonism and slow receptor dissociation kinetics.  It has effects similar to the phenothiazines .  The drug binds preferentially to D 2 and α 1 receptors at low dose (ED 50 = and mg/kg, respectively), and 5-HT 2 receptors at a higher dose (ED 50 = mg/kg). Given that antagonism of D 2 receptors is more beneficial on the positive symptoms of schizophrenia and antagonism of 5-HT 2 receptors on the negative symptoms, this characteristic underlies haloperidol's greater effect on delusions, hallucinations and other manifestations of psychosis.  Haloperidol's negligible affinity for histamine H 1 receptors and muscarinic M 1 acetylcholine receptors yields an antipsychotic with a lower incidence of sedation, weight gain, and orthostatic hypotension though having higher rates of treatment emergent extrapyramidal symptoms .