McKenna's Pharmacology for Nursing, 2e

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C H A P T E R 2 4 Antiparkinsonism agents

with anticholinergics, a risk for decreased antipsychotic therapeutic effectiveness may occur, possibly as a result of a central antagonism of the two agents.

■■ Anticholinergic agents are used to suppress the stimulatory effects of acetylcholine in the substantia nigra, bringing balance into the control of movement. ■■ The adverse effects associated with the anticholinergic drugs are related to blocking of the acetylcholine in the parasympathetic nervous system—dry mouth, constipation, urinary retention, increased heart rate, decreased sweating. ■ ■ Give drug with caution and arrange for a decrease in dose in hot weather or with exposure to hot environments because people are at increased risk for heat prostration because of decreased ability to sweat. ■ ■ Give drug with meals if GI upset is a problem, before meals if dry mouth is a problem and after meals if drooling occurs and the drug causes nausea to facilitate compliance with drug therapy. ■ ■ Monitor bowel function and institute a bowel program if constipation is severe. ■ ■ Ensure that the person voids before taking the drug; monitor urinary output and palpate for bladder distension and residual urine if urinary retention is a problem. ■ ■ Establish safety precautions if CNS or vision changes occur to prevent injury. ■ ■ Provide thorough teaching about topics such as the drug name and prescribed dose, measures to help avoid adverse effects, warning signs that may indicate problems and the need for periodic monitoring and evaluation to enhance knowledge about drug therapy and to promote compliance. ■ ■ Offer support and encouragement to help the person cope with the progressive nature of the disease and long-term drug regimen. Evaluation ■ ■ Monitor response to the drug (improvement in signs and symptoms of Parkinson’s disease or parkinsonism). ■ ■ Monitor for adverse effects (CNS changes, urinary retention, GI slowing, tachycardia, decreased sweating, flushing). ■ ■ Evaluate the effectiveness of the teaching plan (person can give the drug name and dosage, name possible adverse effects to watch for and specific measures to prevent them and discuss the importance of continued follow-up). ■ ■ Monitor the effectiveness of support measures and compliance with the regimen.

Care considerations for people receiving anticholinergic agents

Assessment: History and examination

■ ■ Assess for contraindications or cautions: any known allergies to these drugs to avoid hypersensitivity reactions ; GI depression or obstruction, urinary hesitancy or obstruction, benign prostatic hypertrophy or glaucoma, which may be exacerbated by the peripheral anticholinergic effect of the drug ; cardiac arrhythmias, hypertension or hypotension, which may be increased due to the dominance of sympathetic stimulatory activity due to blockage of parasympathetic activity ; myasthenia gravis, which may be exacerbated by blockage of acetylcholine receptors ; current status related to pregnancy or breastfeeding due to risk of fetal or infant adverse effects ; hepatic dysfunction, which could interfere with drug metabolism and increase risk for toxicity ; and exposure to a hot environment, which may block the individual’s reflex sweating. ■ ■ Perform a physical assessment to determine baseline data for determining the effectiveness of the drug and the occurrence of adverse effects associated with drug therapy. ■ ■ Assess level of orientation and neurological status, including affect, reflexes, bilateral grip strength, gait, tremors and spasticity, to evaluate any CNS effects. ■ ■ Monitor pulse, blood pressure and cardiac output to evaluate for possible adverse effects related to blocking of suppressive action on the heart. ■ ■ Auscultate bowel sounds to evaluate GI motility and detect possible indications of paralytic ileus. ■ ■ Assess urine output and palpate bladder to determine adequate renal and bladder function. ■ ■ Monitor the results of laboratory tests such as renal and liver function tests to determine the need for possible dose adjustment and identify potential toxic effects. Implementation with rationale ■ ■ Arrange to decrease dose or discontinue the drug if dry mouth becomes so severe that swallowing becomes difficult. Provide sugarless lozenges to suck and frequent mouth care to help with this problem.

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