indication

For use as an adjunct in the therapy of all forms of parkinsonism and control of extrapyramidal disorders secondary to neuroleptic drug therapy.

pharmacology

Biperiden is a weak peripheral anticholinergic agent. It has, therefore, some antisecretory, antispasmodic and mydriatic effects. In addition, biperiden possesses nicotinolytic activity. The parenteral form of biperiden is an effective and reliable agent for the treatment of acute episodes of extrapyramidal disturbances sometimes seen during treatment with neuroleptic agents. Akathisia, akinesia, dyskinetic tremors, rigor, oculogyric crisis, spasmodic torticollis, and profuse sweating are markedly reduced or eliminated. With parenteral biperiden, these drug-induced disturbances are rapidly brought under control.

mechanism of action

Parkinsonism is thought to result from an imbalance between the excitatory (cholinergic) and inhibitory (dopaminergic) systems in the corpus striatum. The mechanism of action of centrally active anticholinergic drugs such as biperiden is considered to relate to competitive antagonism of acetylcholine at cholinergic receptors in the corpus striatum, which then restores the balance.

toxicity

LD₅₀=760 mg/kg (Orally in rats). Signs of overdose include dilated and sluggish pupils, warm, dry skin, facial flushing, decreased secretions of the mouth, pharynx, nose, and bronchi, foul-smelling breath, elevated temperature, tachycardia, cardiac arrhythmias, decreased bowel sounds, urinary retention, delirium, disorientation, anxiety, hallucinations, illusions, confusion, incoherence, agitation, hyperactivity, ataxia, loss of memory, paranoia, combativeness, and seizures.

biotransformation

The metabolism of biperiden is not completely understood, but does involve hydroxylation.

absorption

87% bioavailability

drug interactions

Donepezil: Possible antagonism of action

Galantamine: Possible antagonism of action

Haloperidol: The anticholinergic increases the risk of psychosis and tardive dyskinesia

Rivastigmine: Possible antagonism of action

Tacrine: The therapeutic effects of the central acetylcholinesterase inhibitor, Tacrine, and/or the anticholinergic, Biperidin, may be reduced due to antagonism. The interaction may be beneficial when the anticholinergic action is a side effect. Monitor for decreased efficacy of both agents.

Trimethobenzamide: Trimethobenzamide and Biperiden, two anticholinergics, may cause additive anticholinergic effects and enhance their adverse/toxic effects. Monitor for enhanced anticholinergic effects.

Triprolidine: Triprolidine and Biperiden, two anticholinergics, may cause additive anticholinergic effects and enhance their adverse/toxic effects. Monitor for enhanced anticholinergic effects.

Trospium: Trospium and Biperiden, two anticholinergics, may cause additive anticholinergic effects and enhanced adverse/toxic effects. Monitor for enhanced anticholinergic effects.