McKenna's Pharmacology for Nursing, 2e

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P A R T 2  Chemotherapeutic agents

Care considerations for people receiving anti-hepatitis B or C agents

■ ■ Provide the following teaching:

KEY POINTS ■■ Hepatitis B and C are serious-to-potentially fatal viral infections of the liver spread by blood or blood products, sexual contact, or contaminated needles or instruments. Hepatitis B has a higher mortality than other types of hepatitis. ■■ Prevention of infection through use of hepatitis B vaccines and avoiding exposure is essential in stopping the spread of this disease. ■■ Hepatitis B and C used to be treated only with interferons and rest. Entecavir, adefovir and telbivudine are antivirals now available for the treatment of hepatitis B. Boceprevir and telaprevir are used for the treatment of hepatitis C. LOCALLY ACTIVE ANTIVIRAL AGENTS Some antiviral agents are given locally to treat local viral infections. These agents include ganciclovir ( Vitra- sert ) and imiquimod ( Aldara ). Therapeutic actions and indications These antiviral agents act on viruses by interfering with normal viral replication and metabolic processes. They are indicated for specific, local viral infections (see Table 10.5). –– Have regular blood tests and medical follow-up. –– Take precautions to maintain a constant supply of the drug, because it must be taken continually, and avoid missing doses. –– Realise that GI upset, with nausea and diarrhoea, is common with these drugs. –– Report severe weakness, muscle pain, palpitations, yellowing of the eyes or skin and trouble breathing. Evaluation ■ ■ Monitor response to the drug (decreased viral load of hepatitis B or C). ■ ■ Monitor for adverse effects (liver or renal dysfunction, headache, nausea, diarrhoea). ■ ■ Evaluate the effectiveness of the teaching plan (person can name the drug, dosage, possible adverse effects to watch for and specific measures to avoid adverse effects). ■ ■ Monitor the effectiveness of comfort and safety measures and compliance with the drug regimen. KEY POINTS

Assessment: history and examination

■ ■ Assess for contraindications or cautions : any history of allergy to any of the agents to avoid hypersensitivity reactions ; renal dysfunction, which could be exacerbated by the nephrotoxic effects of these drugs ; severe liver impairment, which could affect the metabolism and exacerbate the liver toxicity of these drugs ; and pregnancy and breastfeeding because the potential effects of these drugs on the fetus or baby are not known. ■ ■ Perform a physical assessment to establish baseline data for assessing the effectiveness of these drugs and the occurrence of any adverse effects associated with drug toxicity. ■ ■ Assess body temperature to monitor underlying disease. ■ ■ Assess level of orientation and reflexes to assess for CNS changes. ■ ■ Evaluate renal and liver function tests to monitor for developing toxicity and to determine drug effectiveness. ■ ■ Monitor renal and hepatic function prior to and periodically during therapy to detect renal or hepatic function changes and determine the need for possible dose reduction or institute treatment as needed. ■ ■ Withdraw the drug and monitor the person if they develop signs of lactic acidosis or hepatotoxicity because these adverse effects can be life threatening. ■ ■ Caution person to not stop the medication and to take it continually because acute exacerbation of hepatitis B or C can occur when the drug is stopped. ■ ■ Advise women of childbearing age to use barrier contraceptives because the potential adverse effects of this drug on the fetus are not known. ■ ■ Advise women who are breastfeeding to find another method of feeding the baby while using the drug because the potential toxic effects on the baby are not known. ■ ■ Advise people that these drugs do not cure the disease and there is still a risk of transferring the disease, so the person should continue to take appropriate steps to prevent transmission of hepatitis B or C. ■ ■ Instruct the person about the drug prescribed to enhance knowledge about drug therapy and to promote compliance. Implementation with rationale