Haloperidol use may lead to the development of symptoms that resemble Parkinson's disease, but that are not caused by Parkinson's. These symptoms may include a taut or mask-like expression on the face, drooling, tremors, pill-rolling motions in the hands, cogwheel rigidity (abnormal rigidity in muscles, characterized by jerky movements when the muscle is passively stretched), and a shuffling gait. Taking the anti-Parkinson drugs benztropine mesylate or trihexyphenidyl hydrochloride along with haloperidol help to control these symptoms. Medication to control Parkinsonian-like symptoms may have to be continued after haloperidol is stopped. This is due to different rates of elimination of these drugs from the body.
As far as we can tell, while currently blinded, the time to onset of sedation has ranged anywhere from 6 minutes to just over 20 minutes. Patients who reached adequate sedation did not ever require "rescue" doses of additional ketamine to complete the laceration repairs, which were limited to simple lacerations less than 5 cm and did not require a consult service to perform the repair. Recovery times have been comparable to patients who have received IV ketamine. Unfortunately, since we are still blinded at this time, we cannot make any further comments regarding a specific dose and its effect.
The dose of Haldol Decanoate 50 or Haldol Decanoate 100 should be expressed in terms of its haloperidol content. The starting dose of haloperidol decanoate should be based on the patient's age, clinical history, physical condition, and response to previous antipsychotic therapy. The preferred approach to determining the minimum effective dose is to begin with lower initial doses and to adjust the dose upward as needed. For patients previously maintained on low doses of antipsychotics (. up to the equivalent of 10 mg/day oral haloperidol), it is recommended that the initial dose of haloperidol decanoate be 10–15 times the previous daily dose in oral haloperidol equivalents; limited clinical experience suggests that lower initial doses may be adequate.