McKenna's Pharmacology for Nursing, 2e

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P A R T 4  Drugs acting on the central and peripheral nervous systems

■ ■ Assess for baseline status before beginning therapy to check for occurrence of any potential adverse effects . Assess for the following: temperature and weight; skin colour and lesions; affect, orientation, reflexes and vision; pulse, blood pressure and perfusion; respiratory rate, adventitious sounds and presence of chronic pulmonary disease; and bowel sounds on abdominal examination. ■ ■ Perform laboratory tests, including renal and liver function tests and full blood count (FBC). Refer to the Critical thinking scenario for a full discussion of care for a person dealing with anxiety . ■ ■ Do not administer intra-arterially because serious arteriospasm and gangrene could occur . Monitor injection sites carefully for local reactions to institute treatment as soon as possible. ■ ■ Do not mix intravenous (IV) drugs in solution with any other drugs to avoid potential drug–drug interactions . ■ ■ Give parenteral forms only if oral forms are not feasible or available, and switch to oral forms, which are safer and less likely to cause adverse effects , as soon as possible. ■ ■ Give IV drugs slowly because these agents have been associated with hypotension, bradycardia and cardiac arrest . ■ ■ Arrange to reduce the dose of narcotic analgesics in people receiving a benzodiazepine to decrease potentiated effects and sedation . benzodiazepines in bed for a period of at least 3 hours. Do not permit ambulatory people to operate a motor vehicle after an injection to ensure safety . ■ ■ Monitor hepatic and renal function, as well as FBC, during long-term therapy to detect dysfunction and to arrange to taper and discontinue the drug if dysfunction occurs . ■ ■ Taper dose gradually after long-term therapy, especially in epileptic individuals. Acute withdrawal could precipitate seizures in these people. It may also cause withdrawal syndrome . tolerate drug effects , such as having them void before dosing, instituting a bowel program as needed, giving food with the drug if GI upset is severe, providing environmental control (lighting, temperature, stimulation), taking safety precautions (use of side rails, assistance with ambulation) and aiding orientation. ■ ■ Provide thorough teaching, including drug name, prescribed dose, measures for avoidance of adverse ■ ■ Maintain people who receive parenteral ■ ■ Provide comfort measures to help people Implementation with rationale

effects and warning signs that may indicate possible problems. Instruct people about 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 diagnosis and the drug regimen . ■ ■ If necessary, use flumazenil (Box 20.3), the benzodiazepine antidote, for the treatment of overdose . ■ ■ Monitor response to the drug (alleviation of signs and symptoms of anxiety; sleep; sedation). ■ ■ Monitor for adverse effects (sedation, hypotension, cardiac arrhythmias, hepatic or renal dysfunction, blood dyscrasias). ■ ■ Evaluate the effectiveness of the teaching plan (person can give the drug name, dosage, possible adverse effects to watch for, specific measures to help avoid adverse effects and the importance of continued follow-up). ■ ■ Monitor the effectiveness of comfort measures and compliance with the regimen. Flumazenil ( Anexate ), a benzodiazepine antidote, acts by inhibiting the effects of the benzodiazepines at the gamma-aminobutyric acid (GABA) receptors. It is used for three purposes: to treat benzodiazepine overdose, to reverse the sedation caused by benzodiazepines that are used as adjuncts for general anaesthesia, and to reverse sedation produced for diagnostic tests or other medical procedures. Flumazenil, which is available for IV use only, is injected into the tubing of a running IV. The drug has a rapid onset of action that peaks 5 to 10 minutes after administration. It is metabolised in the liver. Because this drug has a half-life of about 1 hour, it may be necessary to repeat injections of flumazenil if a long- acting benzodiazepine was used. People who receive flumazenil should be monitored continually, and life-support equipment should be readily available. If the person has been taking a benzodiazepine for a long period, administration of flumazenil may precipitate a rapid withdrawal syndrome that necessitates supportive measures. Headache, dizziness, vertigo, nausea and vomiting may be associated with use of flumazenil. ■■ BOX 20.3  A benzodiazepine antidote Evaluation