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C H A P T E R 1 7  Immune modulators

Rituximab is antibodies specific to sites on activated B lymphocytes. Natalizumab is an antibody specific to surface receptors on all leucocytes except neutrophils. Omalizumab is an antibody to immunoglobulin E, an important factor in allergic reactions. It has not had a great deal of success because of related respiratory adverse effects. Palivizumab is specific to the antigenic site on res- piratory syncytial virus (RSV); it inactivates that virus. It is used to prevent RSV disease in high-risk children. Ustekinumab are antibodies specific to interleukins. Pharmacokinetics With the exception of erlotinib (an oral agent), all of the monoclonal antibodies have to be injected. They can be given IV, IM or SC. Because antibodies are proteins, they are rapidly broken down in the GI tract. They are pro- cessed by the body like naturally occurring antibodies. Contraindications and cautions Monoclonal antibodies are contraindicated in the presence of any known allergy to the drug or to murine products and in the presence of fluid overload. They should be used cautiously with fever (treat the fever before beginning therapy) and in individuals who have had previous administration of the monoclonal antibody ( serious hypersensitivity reactions can occur with repeat administration ). Because of the potential for adverse effects, they should not be used during pregnancy or breastfeeding unless the benefit clearly outweighs the potential risk to the fetus or neonate. Adverse effects The most serious adverse effects associated with the use of monoclonal antibodies are acute pulmonary oedema (dyspnoea, chest pain, wheezing), which is asso- ciated with severe fluid retention, and cytokine release syndrome (flu-like symptoms that can progress to third-spacing of fluids and shock). Other adverse effects that can be anticipated include fever, chills, malaise, myalgia, nausea, diarrhoea, vomiting and increased sus- ceptibility to infection. Erlotinib is reserved for individuals whose disease has progressed after other therapies. The manufacturer of natalizumab stopped market- ing the drug weeks after its release because of reports of CNS complications. It was returned to the market in June 2006 with warnings about the potential for CNS complications. Clinically important drug–drug interactions Use caution and arrange to reduce the dose if a monoclonal antibody is combined with any other

immunosuppressant drug because severe immune sup- pression with increased infections and neoplasms can occur.

Prototype summary: Basiliximab Indications: Treatment of acute organ rejection in individuals who have undergone renal transplantation. Actions: Monoclonal antibody to the antigen of human T cells; functions as an immunosuppressant by enabling T cells. Pharmacokinetics: Route Onset Peak Duration IV Minutes 2–7 days 7 days T 1/2 : 47 to 100 hours; metabolised in the tissues. Adverse effects: Headache, insomnia, vomiting, nausea, diarrhoea, general oedema, upper respiratory tract infection, fever, chills, increased susceptibility to infection. ■ ■ Assess for contraindications and cautions: any known allergies to any of these drugs or their components to prevent hypersensitivity reactions ; current status related to pregnancy or breastfeeding because of the potential risk to the fetus or baby ; history of renal or hepatic impairment that might interfere with drug metabolism and excretion ; and history of neoplasm, which could be exacerbated with the use of these drugs . ■ ■ Perform a physical assessment to determine baseline status before beginning therapy and for any potential adverse effects ; inspect the skin to detect the presence of any lesions ; obtain weight to monitor for fluid retention ; monitor temperature to monitor for potential infection ; monitor pulse and blood pressure to assess the cardiac effects of these drugs ; assess level of orientation and reflexes to monitor for any CNS changes associated with drug use . ■ ■ Obtain a baseline ECG to evaluate cardiac function . ■ ■ Assess the person’s renal and liver function, including renal and liver function tests, to determine the appropriateness of therapy and determine the need for possible dose adjustment and toxic drug effects . Care considerations for people receiving immune suppressants Assessment: History and examination