Pharm Chp 8 Antiparasitic Drug Therapy Flashcards
Antiparasitic therapy treats
Protozoa: single celled microorganisms
Helminths: parasitic worms
Protozoal illnesses
Prevalent in tropical regions and in immune-compromised hosts.
Exposure: international travel and immigration from endemic infected areas (where organism lives)
Malaria
Causes high morbidity
Protozoa called Plasmodium, resides in red blood cells
S/S- fever, prostration (extreme fatigue), recurrent chills.
Kills 1 million people per year.
Transmitted by bite of female mosquito
Treatment works during the asexual cycle of the parasite.
Antimalarial agents
prefix (quin)
Quinine sulfate, has sever toxic effects
Mefloquine (Lariam): preventative therapy fewer side effects.
Chloroquine: safe effective, few side effects, given orally or IM.
Treatment agents must be taken 1 to 2 weeks before travel to areas.
Other Protozoal infections
Amebiasis Entamoeba histolytica: treatment metronidazole (Flagyl)
Naegleria fowleri
Trichomoniasis: treatment (Flagyl)
Antiprotozoal agents
Metronidazole (Flagyl)
Adverse effects: abdomen cramps, metallic taste darkened urine
Anthelmintic drugs
Used to treat helminthiasis (parasitic worm disease)
Most are effective with single course of therapy.
e.g. drug Mebendazole (Vermox).
Chagas disease
The new AIDS of the Americas
Caused by a parasite called Trypanosoma cruzi. Parasites multiply within cells of the body, infected cells burst, releasing parasites into the blood stream.
Chagas disease phases
Two phases: Acute and Chronic
Acute- several weeks or months, goes unnoticed, very rarely fatal. Most at risk, young children or people with weakened immune systems.
Chronic- more serious, parasite not eliminated, infection remains silent for decades, heart condition called Chagas cardiopathy, enlarged heart, heart failure, altered rhythm and heart attack. Some get GI complications, enlarged esophagus, enlarged colon.
How chagas disease is spread
Most common thru bite of blood sucking insects called triatomes, kissing bugs. Found inside houses, near pet resting areas, areas infested by rodents in or around beds (under mattresses or bedside tables). Bugs usually come out at night, feed on human blood near lips. While feeding on blood they defecate near bite wound, victim touches face near bite then rubs eyes and the parasite then enters body thru eyes.
Drugs to treat chagas disease
Only two drugs used that are not FDA approved:
Nifurtimox and benznidazole.
Even when drugs are available the cost of treatment can be as high as $1000 or more.
