McKenna's Pharmacology for Nursing, 2e

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P A R T 2  Chemotherapeutic agents

CHAPTER SUMMARY ■■ A protozoan is a parasitic cellular organism. Its life cycle includes a parasitic phase inside human tissues or cells. ■■ Malaria is caused by Plasmodium protozoa, which must go through a cycle in the Anopheles mosquito before being passed to humans by the mosquito bite. Once inside a human, the protozoa invade red blood cells. ■■ The characteristic cyclic chills and fever of malaria occur when red blood cells burst, releasing more protozoa into the bloodstream. ■■ Malaria is treated with a combination of drugs that attack the protozoan at various stages in its life cycle. ■■ Amoebiasis is caused by the protozoan Entamoeba histolytica , which invades human intestinal tissue after being passed to humans through unsanitary food or water. It is best treated with metronidazole or tinidazole. ■■ Leishmaniasis, a protozoan-caused disease, can result in serious lesions in the mucosa, viscera and skin. It is treated with systemic pentamidine. ■■ Trypanosomiasis, which is caused by infection with a Trypanosoma parasite, may assume two forms: African sleeping sickness which leads to inflammation of the CNS, and Chagas disease which TEACHING FOR J.C. You have been prescribed metronidazole to treat your amoebic infection. This antiprotozoal drug acts to destroy certain protozoa that have invaded your body. Because it affects specific phases of the protozoal life cycle, it must be taken over a period of time to be effective. It is very important to take all the drug that has been ordered for you. • This drug frequently causes stomach upset. If it causes you to have nausea, heartburn or vomiting, take the drug with meals or a light snack. Provide teaching regarding drug name, dosage, adverse effects, precautions and warning signs to report and hygiene measures to observe. Evaluation Evaluate drug effects: resolution of protozoal infection. Monitor for adverse effects: GI alterations, dizziness, confusion, CNS changes, vision loss, hepatic function, superinfections. Monitor for drug–drug interactions with oral anticoagulants, alcohol or barbiturates. Evaluate effectiveness of teaching program. Evaluate effectiveness of comfort and safety measures.

results in serious cardiomyopathy. These diseases can be treated with systemic pentamidine. ■■ Trichomoniasis is caused by Trichomonas vaginalis . This common cause of vaginitis results in no signs or symptoms in men but serious vaginal inflammation in women. It is treated with metronidazole and tinidazole. ■■ Giardiasis, which is caused by Giardia lamblia , is a very commonly diagnosed intestinal parasite in Australia. This disease may lead to serious malnutrition when the pathogen invades intestinal mucosa. It is treated with metronidazole and tinidazole. ■■ Pneumocystis carinii is an endemic protozoan that does not usually cause illness in humans unless they become immunosuppressed. P. carinii pneumonia (PCP) is the most common opportunistic infection seen in AIDS people. It is treated with inhaled pentamidine and oral atovaquone. ■■ Individuals receiving antiprotozoal agents should be monitored regularly to detect any serious adverse effects, including loss of vision, liver toxicity and so on. • Common effects of this drug include the following: • Nausea, vomiting and loss of appetite: Take the drug with food and have small, frequent meals. • Superinfections of the mouth, skin: These go away when the course of the drug has been completed. If they become uncomfortable, notify your healthcare provider for an appropriate solution. • Dry mouth, strange metallic taste: Frequent mouth care and sucking sugarless lozenges may help. This effect will also go away when the course of the drug is finished. • Intolerance to alcohol (nausea, vomiting, flushing, headache and stomach pain): Avoid alcoholic beverages or products containing alcohol while taking this drug. • Report any of the following to your healthcare provider: sore throat, fever or chills; skin rash or redness; severe gastrointestinal upset; and unusual fatigue, clumsiness or weakness. • Take the full course of your prescription. Never use this drug to self-treat any other infection or give it to any other person. • Tell any doctor, nurse or other healthcare provider that you are taking this drug. • Keep this drug and all medications out of the reach of children.

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