McKenna's Pharmacology for Nursing, 2e

156

P A R T 2  Chemotherapeutic agents

headache and central nervous system (CNS) changes occurring most frequently. Clinically important drug–drug interactions People who receive amphotericin B should not take other nephrotoxic drugs such as nephrotoxic antibiotics or antineoplastics, cyclosporin or corticosteroids unless absolutely necessary because of the increased risk of severe renal toxicity.

■ ■ Evaluate renal and hepatic function tests and full blood count to determine baseline function of these organs and to assess possible toxicity during drug therapy . Implementation with rationale ■ ■ Arrange for appropriate culture and sensitivity tests before beginning therapy to ensure that the appropriate drug is being used . However, in some cases, treatment can begin before test results are known because of the seriousness of the systemic infections. ■ ■ Administer the entire course of the drug to get the full beneficial effects ; this may take as long as 6 months for some chronic infections. ■ ■ Monitor IV sites to ensure that phlebitis or infiltration does not occur . Treat appropriately and restart IV at another site if phlebitis occurs. ■ ■ Monitor renal and hepatic function before and periodically during treatment to assess for possibly dysfunction and arrange to stop the drug if signs of organ failure occur . ■ ■ Provide comfort and safety provisions if CNS effects occur (e.g. side rails and assistance with ambulation for dizziness and weakness, analgesics for headache, antipyretics for fever and chills, temperature regulation for fever) to protect the person from injury . ■ ■ Provide small, frequent, nutritious meals if GI upset is severe. Monitor nutritional status and arrange a dietary consultation as needed to ensure nutritional status . GI upset may be decreased by taking an oral drug with food. ■ ■ Instruct the person to enhance knowledge about drug therapy and to promote compliance . –– Take safety precautions, including changing position slowly and avoiding driving and hazardous tasks, if CNS effects occur. –– Take an oral drug with meals and try small, frequent meals if GI upset is a problem. –– Report to a healthcare provider any of the following: sore throat, unusual bruising and bleeding or yellowing of the eyes or skin, all of which could indicate hepatic toxicity; or severe nausea and vomiting, which could interfere with nutritional state and slow recovery. Evaluation ■ ■ Monitor person’s response to the drug (resolution of fungal infection). ■ ■ Monitor for adverse effects (orientation and affect, nutritional state, skin colour and lesions, renal and hepatic function). ■ ■ Provide the following teaching: –– Follow the appropriate dosage regimen.

Prototype summary: Fluconazole Indications: Treatment of oropharyngeal,

oesophageal and vaginal candidiasis; cryptococcal meningitis; systemic fungal infections; prophylaxis to decrease the incidence of candidiasis in bone marrow transplants. Actions: Binds to sterols in the fungal cell membrane, changing membrane permeability; fungicidal or fungistatic, depending on the concentration of drug

and the organism. Pharmacokinetics: Route Onset

Peak

Duration 2–4 days 2–4 days

Oral

Slow

1–2 hours

IV Rapid

1 hour

T 1/2 : 30 hours; metabolised in the liver and excreted in the urine. Adverse effects: Headache, nausea, vomiting, diarrhoea, abdominal pain, rash.

Care considerations for people receiving systemic antifungals

Assessment: History and examination

■ ■ Assess the person for contraindications or cautions : history of allergy to antifungals to prevent potential hypersensitivity reactions ; history of liver or renal dysfunction that might interfere with metabolism and excretion of the drug ; and pregnancy or breastfeeding because of potential adverse effects to the fetus or infant . ■ ■ Perform a physical assessment to establish baseline data for assessing the effectiveness of the drug and the occurrence of any adverse effects associated with drug therapy ; test orientation and reflexes to evaluate any CNS effects ; and examine skin for colour changes and lesions to monitor for any dermatological effects . ■ ■ Obtain a culture of the infected area to make an accurate determination of the type and responsiveness of the fungus .