Haloperidol + Trihexyphenidyl (Benzhexol)
Indications
Haloperidol + Trihexyphenidyl (Benzhexol) is used for:
Psychoses, Parkinsonism
Adult Dose
Oral
Psychoses, Parkinsonism
Adult: 1-2 tab 2-3 times daily
Child Dose
Renal Dose
Administration
May be taken with or without food. May be taken w/ meals to minimise GI irritation.
Contra Indications
Severe toxic CNS depression; preexisting coma;
Precautions
Epilepsy, allergy, angle-closure glaucoma, benign prostatic hyperplasia; severe cardiac or hepatic disease; extremes in temp (hot and cold weather); presence of acute infections or leucopenia; hyperthyroidism; pregnancy, elderly, children.Patient w/ arteriosclerosis, history of drug idiosyncrasy. CV disease, glaucoma, GI obstruction, prostatic hyperplasia and/or urinary stricture.
Pregnancy-Lactation
Interactions
Adverse Effects
Side effects of Haloperidol + Trihexyphenidyl (Benzhexol) :
Anxiety, drowsiness, depression, anorexia, transient tachycardia, postural hypotension, leukopenia; anticholinergic side effects. Dryness of the mouth, nausea, constipation, vomiting, dizziness, drowsiness, headache, blurred vision, mydriasis, nervousness, tachycardia, urinary hesitancy or retention, increased intraocular tension, angle-closure glaucoma, weakness, rashes, dilatation of the colon, paralytic ileus, and suppurative parotitis.
Potentially Fatal: Neuroleptic malignant syndrome.
Mechanism of Action
Haloperidol blocks postsynaptic dopamine D1 and D2 receptors in the mesolimbic system and decreases the release of hypothalamic and hypophyseal hormones. It produces calmness and reduces aggressiveness with disappearance of hallucinations and delusions.
Trihexyphenidyl HCl is a tertiary amine antimuscarinic which exerts a direct inhibitory effect on the parasympathetic nervous system. It also exhibits a direct spasmolytic action on smooth muscle, weak mydriatic, antisialagogue and cardiovagal blocking effects.