McKenna's Pharmacology for Nursing, 2e

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C H A P T E R 2 5 Muscle relaxants

Implementation with rationale

■■ Centrally-acting skeletal muscle relaxants are used to relieve the effects of muscle spasm. Dantrolene, a direct-acting skeletal muscle relaxant, is used to control spasticity and prevent malignant hyperthermia. ■■ Botulinum toxin type A is used to improve the appearance of moderate to severe glabellar lines and to treat cervical dystonia, severe primary axillary hyperhidrosis, and strabismus and blepharospasm associated with dystonia. spasticity, improvement in movement and activities; improvement in dystonia, facial lines, sweating with botulinum toxins). ■ ■ Monitor for adverse effects (CNS changes, diarrhoea, liver toxicity, urinary urgency). ■ ■ Evaluate the effectiveness of the teaching plan (person can give the drug name and dosage, possible adverse effects to watch for and specific measures to prevent adverse effects, and therapeutic goals). ■ ■ Monitor the effectiveness of comfort measures and compliance with the regimen. adverse effects, warning signs that may indicate possible problems and the need for monitoring and evaluation to enhance knowledge about drug therapy and to promote compliance. ■ ■ Offer support and encouragement to help the person cope with the drug regimen. Evaluation ■ ■ Monitor response to the drug (improvement in

■ ■ Discontinue the drug at any sign of liver

dysfunction. Early diagnosis of liver damage may prevent permanent dysfunction. Arrange for the drug to be discontinued if signs of liver damage appear. A prodrome, with nausea, anorexia and fatigue, is present in 60% of people with evidence of hepatic injury. ■ ■ Do not administer botulinum toxins into any area with an active infection because of the risk of exacerbation of the infection. ■ ■ Monitor intravenous access sites for potential extravasation because the drug is alkaline and very irritating to tissues. ■ ■ Institute other supportive measures (e.g. ventilation, anticonvulsants as needed, cooling blankets) for the treatment of malignant hyperthermia to support the person through the reaction. ■ ■ Periodically discontinue the drug for 2 to 4 days to monitor therapeutic effectiveness. A clinical impression of exacerbation of spasticity indicates a positive therapeutic effect and justifies continued use of the drug. ■ ■ Establish a therapeutic goal before beginning oral therapy (e.g. to gain or enhance the ability to engage in a therapeutic exercise program; to use braces; to accomplish transfer manoeuvres) to promote compliance and a sense of success with therapy. ■ ■ Discontinue the drug if diarrhoea becomes severe to prevent dehydration and electrolyte imbalance. The drug may be restarted at a lower dose. ■ ■ Provide thorough teaching, including drug name, prescribed dosage, measures for avoidance of

KEY POINTS

CRITICAL THINKING SCENARIO Skeletal muscle relaxants for cerebral palsy

THE SITUATION L.G. is 26 years old. He was diagnosed with cerebral palsy shortly after his birth. He lives in the community in a group home with six other affected people. Two adult caregivers provide supervision. In the past few months, L.G.’s spasticity has progressed severely, making it impossible for him to carry on his daily activities without extensive assistance. Following a clinical evaluation, his healthcare team suggests trying a course of dantrolene therapy. After learning about the risks of dantrolene-related hepatic dysfunction, L.G. decides that the benefits of dantrolene therapy are more important to him than the risks of

hepatotoxicity. The healthcare team proceeds with a complete physical examination, including liver enzyme analysis. Therapy begins and a clinic staff member schedules L.G. for a visit by a community nurse in 4 days. CRITICAL THINKING What basic principles must be included in the care plan for L.G. for the visiting nurses? Think about the importance of including the adult caregivers in any teaching or evaluation programs. Consider specific problems that could develop that L.G. would be unable to handle on his own.