Antimalarials Flashcards
P. Falciparum
Malignant tertian malaria. Most lethal. Fever occurs every third day. No secondary tissue forms. Cerebral malaria. Has many drug resistant forms.
P. Vivax
Benign tertian malaria. Fever occurs every third day. Has dormant forms in the liver (hypnozoites). Relapses for months/years. Duffy antigen was thought to be protective but isn’t.
P. ovale
Rare. Has secondary tissue forms in the liver (hypnozoites). Relapses.
P. Malariae
Quartan malaria. Fever occurs every four days. No tissue forms but can cause chronic infection.
Blood Schizonticides
Act on RBC forms. Provide a clinical cure for vivax and ovale and a radical cure for malariae and faliparum.
Tissue schizonticides
Act on the hepatic stages. Doesn’t effect the symptoms. Kill vivax and ovale to prevent relapse.
Gametocidal agents
Eliminate proliferation. Doesn’t cure the disease just sloes the spread.
Malaria DOC
Chloroquine
Chloroquine (aralen) resistance
especially falciparum due to efflux pumps.
Chloroquine MOA
Actively concentrate in plasmodia food vacule where they interfere with the degradation of hemoglobin producing a toxic by product.
Chloroquine kinetics
Oral. accumulates in melanin-rich tissue. metabolized by CYP3A4.
Cholorquine toxicity
retinal/corneal toxicity, ototoxicity, hemolysis (G6PD deficiency), QT prolongation.
Cholorquine contraindications
psoriasis and porphyria.
Mefloquine (Lariam) uses
Second-line drug for cholorquine-resistant strains.
Mefloquine toxicity
- ) depression of the myocardium, potential cardiac toxicity. (don’t combine with quinine).
- ) seizures and aggravation of latent psychoses.
- ) sleep and behavioral disturbances, vivid dreams
- ) teratogenic
Mefloquine contraindications
history of mental illness or epilepsy and pregnancy
Quinine/Quinidine Gluconate uses
DOC for complicated chloroquine-resistant plasmodia and for unconscious patients.
Quinine/Quinidine Gluconate kinetics
quinine=oral quinidine gluconate=IV. Combined with doxycycline or clindamycin to decrease the length of treatment.
Quinine/Quinidine Gluconate toxicity
Cinchonism (tinnitus, HA, dizziness, flushing, visual distrubances), antiarrhythmis agent, QT prolongation, Hemolysis (G6PD deficiency)
Doxycycline uses
combined with Quinine/Quinidine Gluconate to treat complicated choloroquine-resistant strains.
Fansidar
pyrimethamine+sulfadoxine. Not available in the US
Fansidar uses
presumptive treatment and acute attacks. especially used in affected areas for pregnant women and children.
Malarone
atovaquone+proguanil. Synergistic combo effective in regions with high resistance
Atovaquone MOA
Interferes with mitochondrial processes like the ETC/ATP and pyrimidine biosynthesis.
Malarone uses
Active against blood and tissue forms.
Artemisinin (Qinghaosu)
Most rapid action against falciparum. Not on US market.
Artemeter/lumefantrine (Coartem)
Available in the US for cholorquine resistant falciparum and vivax
Coartem toxicity
Prolonged QT (don’t use in patients with cardiac disease).
Primaquine
Only tissue schizonticide. Active against vivax and ovale for a radical cure.
Primaquine contraindications
G6PD deficiency, SLE, RA, pregnancy (due to unknown fetal G6PD status)
DOC for sensitive plasmodia
chloroquine or hydroxycholorquine
DOC for cholorquine resistant falciparum
- ) quinine with doxycycline or clindamycin
- ) Mefloquine
- ) Malarone
- ) Coartem
DOC for severe malaria
- ) Quinidine with doxycycline or clindamycin
2. ) Artemisinin combo therapy
DOC for vivax or ovale
Always given primaquine to prevent relapse plus:
- ) choroquine
- ) quinine with doxycycline or clindamycin
- ) Mefloquine
- ) Malarone
