McKenna's Pharmacology for Nursing, 2e

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C H A P T E R 9  Antibiotics

Clinically important drug–drug interactions Consider an alternative antibiotic treatment if a person is on sodium valproate. Combination of these drugs can cause serum valproic acid levels to fall and increase the risk of seizures. Avoid concurrent use of imipenem with ganciclovir because this combination may also cause seizures.

discontinuation of drug or decreased dose, as appropriate, if any of these toxicities occurs. ■ ■ Provide safety measures to protect the person if CNS effects, such as confusion, dizziness or seizures, occur. ■ ■ Provide small, frequent meals as tolerated to relieve GI discomfort. Also provide adequate fluids to replace fluid lost with diarrhoea, if appropriate. ■ ■ Ensure that the person is hydrated at all times during drug therapy to minimise renal toxicity from drug exposure. ■ ■ Instruct the person about the appropriate dosage regimen and possible adverse effects to enhance knowledge about drug therapy and to promote compliance. –– Take safety precautions, such as changing position slowly and avoiding driving and hazardous tasks, if CNS effects occur. –– Try to drink a lot of fluids and to maintain nutrition (very important) even though nausea, vomiting and diarrhoea may occur. –– Report difficulty breathing, severe headache, severe diarrhoea, fever and signs of infection. Evaluation ■ ■ Monitor person’s response to the drug (resolution of bacterial infection). ■ ■ Monitor for adverse effects (orientation and affect, superinfections, GI toxicity, severe diarrhoea effects). ■ ■ Evaluate effectiveness of the teaching plan (person can name drug, dosage, possible adverse effects to watch for and specific measures to help avoid adverse effects). ■ ■ Monitor effectiveness of comfort and safety measures and compliance with the therapeutic regimen. ■ ■ Provide the following teaching:

Care considerations for people receiving carbapenems

Assessment: History and examination

■ ■ Assess for possible contraindications or cautions : known allergy to any carbapenem or beta-lactam (obtain specific information about the nature and occurrence of allergic reactions); history of renal disease; history of seizures and current pregnancy or breastfeeding status. ■ ■ Perform physical assessment to establish baseline data for assessing the effectiveness of the drug and the occurrence of any adverse effects associated with drug therapy. ■ ■ Perform culture and sensitivity tests at the site of infection. ■ ■ Conduct orientation and reflex assessment to evaluate any CNS effects of the drug . ■ ■ Assess vital signs: respiratory rate and adventitious sounds to monitor for signs of infection or hypersensitivity reactions ; temperature to assess for signs and symptoms of infection. ■ ■ Perform renal function tests to determine baseline function of the kidneys and, possibly, the need to adjust dose. Implementation with rationale ■ ■ Check culture and sensitivity reports to ensure that this is the drug of choice for this person. ■ ■ Ensure that the person receives the full course of the carbapenem as prescribed to increase effectiveness and decrease the risk for the development of resistant strains of bacteria. ■ ■ Monitor the site of infection and presenting signs and symptoms (e.g. fever, lethargy) throughout the course of drug therapy. Failure of these signs and symptoms to resolve may indicate the need to reculture the site. Arrange to continue drug therapy for at least 2 days after all signs and symptoms resolve to decrease the development of resistant strains of bacteria. ■ ■ Monitor the person regularly for signs of pseudomembranous colitis, severe diarrhoea or superinfections to effectively arrange for

KEY POINTS

KEY POINTS

■■ Carbapenems are used to treat serious infections caused by a wide range of bacteria. ■■ Monitor for GI effects, serious diarrhoea, dizziness and superinfections.

CEPHALOSPORINS The cephalosporins (Table 9.3) were first introduced in the 1960s. These drugs are similar to the penicillins in structure and in activity. Over time, four generations of cephalosporins have been introduced, each group with its own spectrum of activity.