Antimalarials Flashcards
Tissue schizonticides for radical cure or terminal prophylaxis of Ovale & Vivax ?
Primaquine
Tafenoquine
14 days cours for primaquine ; single dose for Tafenoquine
Clinical cure is achieved by killing all parasites responsible for clinical symptoms. Drugs used in clinical cures are called :
Blood schizonticides
Chloroquine
Quinine
Mefloquine
Pyrimethamine
Examples of :
Blood schizonticides
Chemoprophylaxis agent in sensitive falciparum endemic regions ?
Chloroquine
Chloriquine resistant falciparum areae alternative prophylaxis ?
Mefloquine
Atovaquione-proguanil (malorone)
Artemisin
Quinine
DOC for all sensitive plasmodium species :
Chloroquine
MAO of chloroquine :
Inhibition of heme polymerase (cannot convert heme to hemozoin which is less toxic for the parasite)
Mutation in what gene is responsible for rapidly developing resistance of falciparum to chloroquine ?
PfCRT
Most common side effects of chloroquine ?
Cinchonism (tinnitus, vertigo)
Pruritus
Blurry vision and Retinal damage
Prolonged QT interval
Rapid IV use can cause hto, choc
Avoid if hepatic dysfunction, GI issues, psoriasis and prophyria acute attack
Quinine uses :
Uncomplicated mild falciparum infection in combination with clindamycin in children or with doxycycline in adults ;
In chloroquine resistant & multidrug resistant malaria
As first line IV drug in severe p falciparum in **combination with Artesunate **
To delay the emergence of resistance - quinine should NOT be used routinely for prophylaxis.
Main side effects of quinine :
GI
Cinchonism
Hypoglycemia
Hypotension
QT prolongation (cardiac monitoring required when IV infused)
Hemolysis in G6PD deficiency
Feototoxic (avoid in pregnancy)
HSR
Rapidly acting blood schizonticide
Effective in uncomplicated chloroquine resistant & multidrug reisstant P. falciparum infections
Half-life 20 days, enter enterohepatic ciruclation
AVOID in psychiatric conditions, seizure disorders or cardiac conduction defects
Mefloquine
Slow acting blood schizonticide combination of drug that inhibits sequential steps of folate synthesis & produce synergistic effects
Pyramethamine + sulfadoxine (FANSIDAR)
Used in chemoprophylaxis in high risk patients such as HIV, children and in pregnant women in Africa OR for chloroquine-resistant P. falciparum malaria
Also toxoplasmosis & pneumocystitis
Pyramethamine + Sulfadoxine
Main adverse events of Pyramethamine & sulfadoxine treatment ?
Megalobastic anemia (reversed by leucovorin)
SJS (if pt is allergic to sulfa drugs)
Atovaquone + Proguanil (Malarone) use :
Alternative prophylaxis for resistant P. falciparum malaria
Artemisinin mechanism of action :
Rapidly acting blood schizonticide to all malarial parasites
Creating of free radicals when interacts with iron which causes damage to parasite’s proteins.
Highly efficacious, safe and well tolerated but only short acting
Short acting prevents development of resistance but then must always be used in combination with long acting drugs. Specifically with Mefloquine in Southeast Asia and South America.
NOT used in chemoprophylaxis
First line therapy in uncomplicated multi-drug resistant P. falciparum ?
Artemisinin
Recommended therapy in 2nd and 3rd trimesters of pregnancy in uncomplicated falciparum ?
Artemisinin
First trimester quinine + mefloquine/clindamycin preferred.
MAO via redox compounds that act as cellular oxidants which act at tissue level and also limits malaria transmission by acting as a gametocide ?
Primaquine
Some metabolites are responsible for hemolysis and methemoglobinemia ; DO NOT USE IF G6PD deficiency or in pregnancy (fetus will have G6PD def) :
Primaquine
Prior to use, must estimate level of G6PD
Treatment of malaria
First line trx of Leishmaniasis (visceral, mucocutaenous and cutaneous)
Sodium stibogluconate
Side effects of Sodium stibugluconate
Serious renal, hepatic and cardiac (long QT) toxicities + painful abscess at site of inhection, GI, fever & headaches.
NEED PERIODIC MONITORING.
