Anticholinergics
Are drugs that oppose the effects of acetylcholine at receptors sites in the substancia migra and the corpus striatum, thus helping restore chemical balance in the area.
Is a substance that blocks the neurotransmitter acetylcholine in the central and peripheral nervous system
Drug Name Dosage/Route Usual Indication
Benztropine 0.5 – 6mg/day PO may be needed Parkinsoninsm, drug
(Cogentin) 1 – 2 mg IM or IV; reduce dosage in order patient induced parkin sonism
Biperiden
(Akineton) 2MG po T.I.D. to a maximum at 16mg/day Parkinsonism, drug
2mg IM or TV, repeated in ½ hours as neened induced Parkinsonism
Do not give more than four doses/day
Diphenhydramine
(Benadryl) 2 mg PO t.i.d. to q.i.d to am\ minimum of 16mg Parkinsonism, particularly
Per day 2mg IM of IV. In the elderly or those with
Mildforms.
Procyclidine 2m.5 – 5 mg PO or t.i.d Parkinsonism – Control of
excessive saliration
trihexyphenidyl 1 – 2 mg PO dailly initially up to 6 – 10 mg/day adjunct to levodapa in
mg/day maybe needed. Treatment of Parkinsonism
Pharmacokinetics:
Anticholinergics drugs are variably absorbed from the GI tract, reaching peak levels in 1 – 4 hours. They are metabolized in the and excreted by cellular pathways. All of them across the placenta and enter breast milk., They should be use during pregnancy and lactation only if the benefit to the mother clearly out weights the potential risk to the fetus or neonate. The safety and efficacy in children have been established.
Action: The anticholinergics block the action of acetylcholine in the CNS to help normalize the acetylcholine – dopamine imbalances. As a result, these drugs reduce the degree of rigidity and to lesser extent, the tremors associated with parkinson’s disease.
Indication: Anticholinergic drugs are indicated for the treatment of Parkinson, wethe Idiophatic, atheoscierotic, or postencephalitic, and for the relief symptoms of extrapyramidal disorders associated with the use of drugs, including phenothiazines. Although these drugs are not effective as levodapa the treatment advancing cases of the disease, they may be useful as adjunctive theraphy and for patients who no long respond to levodopa.
Adverse affect:
associated with CNS effects the blocking of central acetylcholine receptors
- disorientation
- confusion
- memory loss
- agitation
- Nervousness
- delirium,
- dizziness,
- light – headedness
- weakness.
Contraindication:
The presence of allergy to any of these agents contraindicated in narrow – angle glaucoma, OI obstruction, genitourinary (CGU) obstruction, and Prostatic hypertrophy, all which could be exacerbated by the blocking of acetylcholine receptor side at neuromuscular synapses.
Drug Interactions:
- Drugs are used with other drugs that have anticholinergic properties, including the tricyclic antidepressants and the phenothiazines, ileus and increased risk of toxic psychoses.
- Given in patient monitored closely
- Dosage adjustment should be made
- Supportive measures should be taken
- The antipsychotic drugs are combined with anticholinergics, there is a risk for decreased of therapeutic effect of the antipsychotic possibility because of a central antagonism of two agent.
