anti-protozoa_part2 Flashcards
What is the pharmacokinetics (P/K) of Mefloquine?
Given only orally (local irritation occurs with parenteral use). Well absorbed, extensively bound. Significantly metabolized in the liver, metabolites excreted in stool. Concentrated in liver and lungs. Has a long half-life, so it is given once weekly (due to enterohepatic circulation).
What is the mode of action of Mefloquine?
Not exactly known.
What are the pharmacological effects of Mefloquine?
Blood schizonticidal activity against P. falciparum and P. vivax (malariae and ovale). No effect on hepatic forms. Has quinidine-like effects on the heart (anti-arrhythmic).
What are the primary uses of Mefloquine?
Treatment and prevention of chloroquine-resistant falciparum malaria. Particularly effective when combined with sulfadoxine and pyrimethamine.
What are the adverse effects of Mefloquine?
Common: Nausea, vomiting, headache.
Rare: Neuropsychiatric disturbances (giddiness, confusion, insomnia), psychosis, and convulsions.
What is the pharmacokinetics (P/K) of Quinine?
Bitter-tasting alkaloid. Rapidly absorbed from the small intestine. Moderately protein-bound. Mainly metabolized and excreted in urine (increased excretion with acidic urine). About 10% excreted unchanged.
What is the mode of action of Quinine?
Exact mechanism of action is not known.
What are the antimalarial effects of Quinine?
Rapidly acting and highly effective blood schizonticidal drug against all four species. Gametocidal for P. vivax and P. ovale. No effect on liver stages or sporozoites of any species.
What are the other pharmacological effects of Quinine?
a) Similar butless intense effects on the heart than quinidine.
b) Slight oxytocic effect on gravid uterus (3rd trimester).
c) A curare-like effect at the motor end plate.
What are the main uses of Quinine?
1) Treatment of ** severe falciparum** malaria by slow I.V. route.
2) Oral treatment (7-day course) of falciparum malaria ** resistant to chloroquine (in combination with doxycycline or clindamycin).**
What are the adverse effects of Quinine?
1) Local irritant effects: Oral may lead to nausea/vomiting and pain; IM may cause a sterile abscess.
2) Hemolysis, hypoglycemia: Increased release of insulin by the drug.
3) Cinchonism: Sweating, blurred vision, dizziness, nausea, diarrhea, headache.
4) Blackwater fever: Severe syndrome of intravascular hemolysis, hemoglobinuria, renal failure, with a mortality rate of 20-50%.
