Antiparkinsonian drugs anticholinergic

Anticholinergic drugs can be effective for tremor and dystonic features in some patients but rarely show substantial benefit for bradykinesia or other disabilities. They can be used as monotherapy or in conjunction with other antiparkinsonian drugs. They differ little from each other in therapeutic potential or adverse effects. 

Trihexyphenidyl, an antiparkinsonian drug, possesses central and peripheral anticholinergic actions, as well as a direct relaxant effect on smooth muscle. It reduces muscle rigidity and general stiffness, and has a relatively minor effect on tremors. It is used in Parkinsonism in the form of monotherapy as well as in combination with levodopa. The most common synonyms are parkopan, parkinsan, and cyclodol. 

Anticholinergic drugs - atropine, hyoscine, scopolamine, antiparkinsonian drugs, antipsychotic drugs, antihistamines, antidepressants... 

It s use with anticholinergic antiparkinsonian drugs can lead symptoms similar to atropine poisoning. 

Antiparkinsonian drugs possessing anticholinergic properties (e.g., trihexyphenidyl and ethopropazine)... 

Early dyskinesias occur immediately after neuroleptization and are manifested by involuntary abnormal movements in the head neck and shoulder region. After treatment of several weeks to months, a parkinsonian syndrome (pseudoparkinsonism) (p.188) or akathisia (motor restlessness) may develop. All these disturbances can be treated by administration of antiparkinsonian drugs of the anticholinergic type, such as biperiden. As a rule, these disturbances disappear after withdrawal of neuroleptic medication. Tardive dyskinesia may become evident after chronic neuroleptization for several years, particularly when the drug is discontinued. Its postulated cause is a hypersensitivity of the dopamine receptor system. The condition is exacerbated by administration of anticholinergics. 

In both studies it was found that, during the period of administration of the anticholinergic antiparkinsonian drug, there was worsening of the schizophrenic symptomatology. This effect was found to be more marked in the case of chlorpromazine-treated schizophrenics and it is suggested... 

The efficacy of anticholinergic drugs in parkinsonism is likely due to the ability to block muscarinic receptors in the striatum. In the absence of the inhibitory action of dopamine, the actions of the intrastriatal cholinergic interneurons are unopposed, yielding enhanced stimulation of muscarinic receptors. Blockade of these receptors reduces striatal activity. The muscarinic antagonists exert only modest antiparkinsonian actions and thus are most commonly used during the early stages of the disease or as an adjunct to levodopa therapy. 

Physostigmine, given intravenously, counteracts both the peripheral and central side effects of atropine and other anticholinergic drugs such as thioridazine (neuroleptic), imipramine (antidepressant), and benztropine (antiparkinsonian medication). 

Benztropine Mesylate, USP. Benztropine mesylate. 3o-(diphenylmethoxy)-1 otH.SatH-ttopane methane.sulfonaic (Cogentin), has anticholinergic, antihistaminic. and local anesthetic properties. Its anticholineigic effect makes it applicable as an antiparkinsonian agent. It is about as potent an anticholinergic as atropine and shares some of the side effects of this drug, such as mydriasis and dryness of mouth. Importantly, however, it does not produce central stimulation but instead exerts the characteristic. sedative effect of the antihistamine.s. 

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