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 with all antipsychotic agents HALDOL has been associated with persistent dyskinesias. Tardive dyskinesia, a syndrome consisting of potentially irreversible, involuntary , dyskinetic movements, may appear in some patients on long-term therapy or may occur after drug therapy has been discontinued. The risk appears to be greater in elderly patients on high-dose therapy, especially females. The symptoms are persistent and in some patients appear irreversible. The syndrome is characterized by rhythmical involuntary movements of tongue, face, mouth or jaw (., protrusion of tongue, puffing of cheeks, puckering of mouth, chewing movements). Sometimes these may be accompanied by involuntary movements of extremities and the trunk.
The same authors also demonstrated similar results in healthy volunteers in their previously published study in the May 2012 issue of the same journal titled “ABH Gel is not Absorbed From the Skin of Normal Volunteers,” which found that ABH gel is not absorbed well topically. In that study, lorazepam and Haldol ® were almost undetectable in the blood samples of healthy study subjects; in other words, the plasma samples indicated that ABH gel was clinically or therapeutically insignificant. Therefore, ABH gel in its current formulation should not be used in patients with cancer.