It is a commonly held view among clinicians that intravenously
administered haloperidol has a greater antipsychotic effect than oral
haloperidol. To test this hypothesis, the authors carried out a double-
blind study on patients with acute schizophrenia and patients with
schizophreniform or schizoaffective (with manic features) psychoses. Using
biologically equivalent doses, they found that intravenously administered
haloperidol was slightly more effective during the first 3 hours;
thereafter the route of administration did not make a difference in
effectiveness.Abstract Teaser