Biperiden, sold under the brandname Akineton among others, is a medication used to treat Parkinson disease and certain drug-induced movement disorders. It is not recommended for tardive dyskinesias. It is taken by mouth, injection into a vein, or muscle. Biperiden, sold under the brandname Akineton among others, is a medication used to treat Parkinson disease and certain drug-induced movement disorders. It is not recommended for tardive dyskinesias. It is taken by mouth, injection into a vein, or muscle. Common side effects include blurred vision, dry mouth, sleepiness, constipation, and confusion. It should not be used in people with a bowel obstruction or glaucoma. It is unclear if use in pregnancy or breastfeeding is safe. Biperiden is in the anticholinergic family of medication. Biperiden was approved for medical use in the United States in 1959. It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system. The wholesale cost in the developing world is about US$1.52–12.92 per month. In the United States it costs about $50–100 per month. Biperiden is used for the adjunctive treatment of all forms of Parkinson's disease and for reduced sweating in methadone users (postencephalitic, idiopathic, and arteriosclerotic Parkinson's). It seems to exert better effects in the postencephalitic and idiopathic than in the arteriosclerotic type. Biperiden is also commonly used to improve acute extrapyramidal side effects related to antipsychotic drug therapy, such as akathisia. It relieves muscle rigidity, reduces abnormal sweating related with clozapine and methadone use and salivation, improves abnormal gait, and to lesser extent, tremor. In its role as a synthetic acetylcholine antagonist, biperiden has been analyzed as an alternative anticonvulsant for usage in the treatment of intoxication by organophosphorus nerve agents, such as sarin. It was also suggested by IV route for neuroleptic malignant syndrome. Children and adolescents aged 1 year and older may be treated. The clinical experience is mainly on the short-term treatment of acute drug induced dystonic reactions. Doses should be reduced according to the weight of the patients.