Ch. 12 Antiprotozoal Agents Flashcards
What are risk factors for protozoal infections? And what is a protozoa?
- Unsanitary and crowded conditions
- Third world countries
- Poor hygienic practices
Protozoa is a single celled organism that pass through several stages in their lifecycle, including at least one phase as a human parasite;
Other causes of protozoal infections
Insect bites which cause
Malaria
Trypanosomiasis - causes African sleeping sickness, transmitted by Tsetse fly.
And Chagas’ disease caused by Trypanosoma Cruzi, caused by common house fly.
Leishmaniasis- passed by sand flies
Protozoa thrive in
Tropical climates
These are caused by trypanosomes and typically transmitted by biting insects, especially sleeping sickness and Chagas disease.
Define Trypanosomiasis
African sleeping sickness, which is caused by a protozoan that inflames the CNS and is spread to humans by the bite of the tsetse fly, Also, Chagas disease, which causes a serious cardiomyopathy after the bite of the housefly
TAG
Other causes of protozoal infections
Ingestion Or contact with the causal organism anebiadis, giardiasis, trichomoniasis
Malaria is caused by
Hint: genus is plasmodium
Anopheles mosquito
Amebiasis is
Amebic dysentery (type of gastroenteritis that results in bloody diarrhea) which is caused by intestinal invasion of the trophozoite stage of the protozoan Entamoeba histolytica
Amebiasis - symptoms of
Severe diarrhea with abdominal pain
Trichomoniasis is
Hint: sex
A sexually transmitted infection caused by a parasite. That causes vaginitis in women, which may cause foul smelling vaginal discharge in women and no symptoms in men.
Giardiasis is and what does it cause?
Protozoal intestinal infection that causes severe diarrhea and epigastric distress, may lead to serious malnutrition
Plasmodium is a protozoan that causes….
malaria in humans; its lifecycle includes the Anopheles mosquito, which injects protozoa into humans
Antiprotozoal Agents effects in older adults
Older patients may be more susceptible to the adverse effects they should be monitored closely. Patients with hepatic dysfunction are at increased risk for worsening hepatic problems and toxic effects of many of these drugs if hepatic dysfunction is expected extreme age alcohol abuse use of other hepatotoxic drugs the dose may need to be Lowered and the patient monitoring more frequently
Antiprotozoal Agents (meds) effects on children
Children are very sensitive to the effects of most antiprotozoal drugs and more severe reactions can be expected. Many of these drugs do not have proven safety and efficacy in children and extreme caution should be used.
Antiprotozoal effects in adults
Hint: prophylactic and when else to take?
Adults should be well advised about the need for prophylaxis against various protozoal infection and the need for immediate treatment if the disease is contracted. Pregnant and nursing women should not use these drugs unless the benefit clearly outweighs the potential risk to the fetus or neonate women should be advised to use barrier contraceptives if these drugs are used.
Actions of Antiprotozoal Drugs
Inhibit protein DNA synthesis in susceptible protozoa pharmacokinetics – readily absorbed and highly protein bound in circulation or metabolized in the liver and excreted in the urine and feces generally nephrotoxic and
Which organ do these parasites invade?
They lay dormant until they eventually find their way to the liver, or they multiply and then invade more red blood cells, again causing the acute cycle
Antiprotozoal drugs contraindications
Known allergy
Pregnancy
CNS
HEPATIC (liver disease) monitor patients who are on these meds
Antiprotozoal Adverse Effects Chloroquine
Chloroquine- seizures, confusion, CNS
Headache, dizziness, ataxia, nausea, vomiting, diarrhea
Is the mainstay of antimalarial therapy for infections.
Chloroquine (Aralen)
Prevention and tx of Plasmodium malaria; tx of extra intestinal amebiasis
Antiprotozoal Drug-drug interaction
Hint: A, A, D
Alcohol
Anticoagulants (Warfarin, Coumadin)
Disulfiram is a drug to help alcoholics quit drinking. If taken with Antiprotozoal drug will make them sick such as N/V, chest pain, mental confusion, weakness, choking, breathing difficulty, anxiety
Malaria signs and symptoms
Related to the destruction of red blood cells and toxicity to the liver
Malaria treatment
Aims at attacking the parasite at the various stages of its development inside and outside the human body
How does malaria occur and spread?
Mosquito bite injects plasmodium falciparum into your blood. They travel to the liver, evolve into merozoite and get into the RBC’s. The next mosquito sucks this from your blood and then injects the plasmodium falciparum to the next customer, thus Malaria circle of life
Plasmodium falciparum is
The most dangerous type. Infection with this protozoan results in an acute, rapidly fulminating disease with high fever, severe hypotension, swelling and reddening of the limbs, loss of RBC’s, and even death. Also causes cancer.
