Antiprotozoal Agents Chapter 12

Causes of Protozoal Infections Insect Bites Malaria Trypanosomiasis Leishmaniasis Ingestion or Contact with the Causal Organism Amebiasis Giardiasis Trichomoniasis

Protozoal Parasites Identified as Causes of Malaria Plasmodium falciparum Considered the most dangerous type of protozoan Plasmodium vivax Milder form of the disease; seldom results in death Plasmodium malariae Endemic in tropical countries; mild symptoms Plasmodium ovale Rarely seen; in the process of being eradicated

Life Cycle of Plasmodium

Antimalarials Chloroquine (Aralen) Prevention and treatment of plasmodial malaria; treatment of extraintestinal amebiasis Halofantrine (Halfan) Treatment of plasmodial malaria in combination with other drugs Hydroxychloroquine (Plaquenil) Treatment of plasmodial malaria in combination with other drugs (particularly primaquine)

Antimalarials (cont.) Mefloquine (Lariam) Prevention and treatment of plasmodial malaria in combination with other drugs Primaquine (generic) Prevention of relapses of Plasmodium vivax and Plasmodium malariae infections; radical cure of P. vivax malaria

Antimalarials (cont.) Pyrimethamine (Daraprim) Prevention of plasmodial malaria in combination with other agents to suppress transmission; treatment of toxoplasmosis Quinine (generic) Treatment of chloroquine-resistant plasmodial infections

Question Please answer the following statements as true or false. Halofantrine (Halfan) is an antimalarial drug used in the treatment of plasmodial malaria. It is typically used in combination with other drugs.

Answer True Rationale: Halofantrine (Halfan): Treatment of plasmodial malaria; used in combination with other drugs

Antimalarials - Action Interrupt plasmodial reproduction of protein synthesis Agents which do not appear to affect the sporozoties are used for prophylaxis

Antimalarials - Contraindications Known Allergy Liver Disease Alcoholism Lactation Caution: Retinal disease of damage Psoriasis

Antimalarials – Adverse Effects Headache Dizziness Fever Chills Malaise Nausea Vomiting Hepatic Dysfunction

Antimalarials – Drug-to-Drug Interaction Quinine derivatives and quinine is at risk for cardiac toxicity. Antifolate drugs with pyrimethamine can cause increase risk of bone marrow suppression.

Other Antiprotozoal Drugs Actions Inhibit DNA synthesis Contraindications Known allergy, pregnancy, CNS disease, hepatic disease Adverse Reactions Headache, dizziness, ataxia, nausea, vomiting, and diarrhea

Malaria Signs and Symptoms Related to the destruction of red blood cells and toxicity to the liver Treatment Aims at attacking the parasite at the various stages of its development inside and outside the human body

Other Protozoal Infections Amebiasis Leishmaniasis Trypanosomiasis Trichomoniasis Giardiasis Pneumocystic carinii

Risk Factors for Protozoal Infections Unsanitary Conditions Poor Hygienic Practices

Question When are antiprotozoal medications contraindicated? A. Renal disease B. Anemia C. CNS disease D. Cardiovascular disease

Answer C. CNS disease Rationale: Contraindications are known allergy, pregnancy, CNS disease, hepatic disease.

Prototype Antiprotozoal Agent

Prototype Antiprotozoal Agent

Use of Antiprotozoal Therapy Across the Life Span

Common Antiprotozoal Agents Atovaquone (Mepron) Especially active against PCP Metronidazole (Flagyl, MetroGel, Noritate) Treats amebiasis, trichomoniasis, and giardiasis Pentamidine (Pentam 300, NebuPent) Treats PCP, trypanosomiasis, and leishmaniasis Tinidazole (Tindamax) Treats trichomoniasis, giardiasis, and amebiasis

Nursing Considerations for Antimalarial Agents Assessment: History and Physical Exam-any allergy to any of the antimalarial, CNS disease, liver function Nursing Diagnosis-acute pain r/t GI/CNS effects of the drug; Imbalanced nutrition: less than body requirements r/t GI effects of the drug.. Implementation Evaluation

Nursing Considerations for Antiprotozoal Agents Assessment: History and Physical Exam Nursing Diagnosis Implementation Evaluation

Question The nurse is caring for a patient with Parkinson’s disease. When developing the care plan for this patient which of the following would be an appropriate nursing diagnosis? A. Constipation related to dopaminergic effects B. Diarrhea related to dopaminergic effects C. Risk for injury related to CVS effects and incidence of orthostatic hypotension D. Risk for injury related to CVS effects and incidence of PVD

Answer A. Constipation related to dopaminergic effects Rationale: Nursing diagnoses related to drug therapy might include: Constipation related to dopaminergic effects; Risk for injury related to CNS effects and incidence of orthostatic hypertension