McKenna's Pharmacology for Nursing, 2e

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P A R T 2  Chemotherapeutic agents

trypanosomiasis, trichomoniasis and giardiasis. These infections, which are caused by single-celled protozoa, are usually associated with unsanitary, crowded condi- tions and use of poor hygienic practices. People travelling to other countries may encounter these infections, which are also now appearing increasingly in Australia and New Zealand. Box 12.5 discusses the impact of travel and tourism on the spread of pathogens. Amoebiasis Amoebiasis , an intestinal infection caused by Entam- oeba histolytica , is often known as amoebic dysentery. E. histolytica has a two-stage life cycle (see Figure 12.3). The organism exists in two stages: (1) a cystic, dormant stage, in which the protozoan can live for long periods outside the body or in the human intestine, and (2) a trophozoite stage in the ideal environment—the human large intestine. World travel and the spread of pathogens Nowadays, people are travelling to more exotic areas of the world than ever before. Because of this, people are being exposed to more pathogens than ever before, and they are also potentially spreading pathogens to different areas of the world. Pathogens that are endemic in one area of the world and cause mild disease to the local population there can be quite devastating in a population that has not previously been exposed to that pathogen. World health agencies and governments have established guidelines for prophylaxis and treatment of such diseases for travellers. People who are planning to travel out of the country should contact their local Health Department or the Australian Government Department of Foreign Affairs andTrade SmartTraveller http://smartraveller.gov.au/index.html for the latest information on what prophylactic measures are required in the area they plan to visit and to learn about potential health hazards in that area.The information is updated frequently; treatment and prophylaxis suggestions are based on current clinical experience in the area and should be consulted regularly. Nurses should access this information when working with people who are travelling to provide pertinent teaching points and to ensure that appropriate prophylactic measures are taken. Nurses and midwives caring for people with tropical diseases should access this information regularly for best treatment practices. People who have been travelling to other areas of the world and who present with any illness should be questioned about where they travelled, what precautions (including prophylactic measures) they took, and when they first experienced any signs or symptoms of illness. The SmartTraveller website can be consulted about diagnosis and treatment guidelines for any tropical disease that is unfamiliar to a healthcare provider, as well as about what precautions should be used in caring for such people. The evidence BOX 12.5

■■ A protozoan is a parasitic cellular organism. Its life cycle includes a parasitic phase inside human tissues or cells. ■■ Malaria is the most common protozoal infection and is spread to humans by the bite of an Anopheles mosquito. The signs and symptoms of malaria are related to the destruction of red blood cells and toxicity to the liver. ■■ Antimalarial agents attack the parasite at the various stages of its development inside and outside the human body. OTHER PROTOZOAL INFECTIONS Other protozoal infections that are encountered in clinical practice include amoebiasis, leishmaniasis, ■ ■ Provide small, frequent, nutritious meals if GI upset is severe to ensure adequate nutrition . Monitor nutritional status and arrange a dietary consultation as needed. Taking the drug with food may also decrease GI upset. ■ ■ Instruct the person concerning the appropriate dosage regimen and the importance of adhering to the drug schedule 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 the drug with meals and try small, frequent meals if GI upset is a problem. –– Report blurring of vision, which could indicate retinal damage; loss of hearing or ringing in the ears, which could indicate CNS toxicity; and fever or worsening of condition, which could indicate a resistant strain or non-effective therapy. Evaluation ■ ■ Monitor response to the drug (resolution of malaria or prevention of malaria). ■ ■ Monitor for adverse effects (orientation and affect, nutritional state, skin colour and lesions, hepatic function, and visual and auditory changes). ■ ■ Evaluate the effectiveness of the teaching plan (person can name the drug, dosage, possible adverse effects to watch for and specific measures to help avoid adverse effects). ■ ■ Monitor the effectiveness of comfort and safety measures and compliance with the regimen. ■ ■ Provide the following teaching: KEY POINTS