Antimalarials Flashcards
What are the antimalarials
Chloroquine Quinidine Quinine Mefloquine Primaquine Atovaquone Proguanil Pyrimethamine Sulfadoxine Doxycycline Artemisinins Halofantrine Lumefantrine
DOC Tx and prophylaxis Vivax and Ovale, uncomplicated Falciparum
Chloroquine
DOC severe Falciparum
Quinidine
Quinine
Artemisinins (IV)
Pregnant prophylaxis against Chloroquine-resistant
Mefloquine
DOC dormant liver form eradication
Primaquine
Tx and Prophylaxis uncomplicated Falciparum
Atovaquone
Proguanil
Can cause Cinchonism
Quinidine
Quinine
Great for blood schizonts, but not liver
Chloroquine
Quinidine
Quinine
Safe in pregnancy
Chloroquine Quinidine Quinine Mefloquine Atovaquone Pyrimethamine Proguanil Sulfadoxine Artemisinins
Contraindicated in pregnancy
Primaquine
Doxycycline\Halofantrine
How does Chloroquine work
Raises internal pH of parasite
Interfere with Hb metabolism to hemozoin
Lysis of parasite and RBC
Who do you not give Chloroquine to
G6PD deficiency
Psoriasis
Porphyria
Retinal/Visual field abnormalities
How does Chloroquine resistance arise
Mutation in Falciparum putative transporter (PfCRT)
When can you give Chloroquine for Falciparum
Uncomplicated disease
Chloroquine AE
Pruritis
N/V
Abdomenal pain
HA, anorexia, malaise, urticaria
What is the most important Chloroquine AE
Retinopathy
What should you combine with Doxycycline for severe Falciparum
Quinidine
Quinine
How do the Quinidines work
Decreased O2 and CHO metabolism
Intercalates DNA
What do you not combine Quinidines with
Mefloquine
Quinidine drug interactions
Increase serum Warfarin and Digoxin
Where is Quinidine resistance rising
SE Asia
What are the Quinidine AE
QT prolongation Blackwater fever HS Heme disturbance Hypoglycemia (increases insulin) Uterine contraction Hypotension
What is Blackwater Fever
RBC hemolysis releasing Hb into blood and urine
Leads to kidney failure
Useful for mild/moderate Chloroquine resistant strains
Mefloquine
How does Mefloquine work
Destroys asexual blood forms
Why don’t you combine Mefloquine and Quinidines
Chemically related, so similar resistances
When should you discontinue Quinidines in pregnancy
If there’s hemolysis
Who should avoid Quinidines
Visual/Auditory/Cardiac problems
When is Mefloquine contraindicated
Epilepsy, psych problems
Arrhythmia, drug sensitivities
What is the main Mefloquine AE
Neuropsychiatric toxicity
What are the high dose Mefloquine AE
Leukocytosis Thrombocytopenia Aminotransferase elevation Arrhythmias Bradycardia
What else do you not give Mefloquine with
Halofantrine
What is Malarone
Atovaquone + Proquanil
How does Malarone work
Disrupts Mito ETC
What are the Malarone AE
Gi upset
HA
Rash
Which schizonts is Malarone effective against
Tissue, RBC
What are the inhibitors of Folate Synthesis
Pyramethamine
Proguanil
Sulfadoxine
What are the Folate Synthesis inhibitors good for
Chemoprophylaxis
Intermittent prevention in high risk pts
What can you give for mild/moderate Chloroquine-resistant falciparum
Pyrimethamine
Sulfadoxine
Which Folate Synthesis inhibitor is slow against RBC form
Pyrimethamine + Proguanil
Which Folate Synthesis inhibitor is good for some hepatic forms
Proguanil
Which Folate Synthesis inhibitor is good for RBC forms
Sulfadoxine
What does Sulfadoxine inhibit
Dihydropteroate reductase
What does Pyrimethamine + Proguanil inhibit
DHF reductase
Folate Synthesis inhibitor AE
GI problems
Rash
Itching
Proguanil AE
Mouth ulcers
Alopecia
Pyrimethamine + Sulfadoxine AE
Erythema multiforme
Stevens-Johnson syndrome
Sulfadoxine toxicities
Hematological GI CNS Derm Renal
What is an alternative to Doxycycline
Clindamycin
What are the Doxycycline AE
Photosensitivity Discoloration and Hypoplasia of teeth Growth stunting GI upset Vaginal candidiasis Hepatotoxicity in pregnancy
Works on RBC stage of all parasites
Halofantrine
Lumefantrine
What are the Artemisinins
Artesunate
Artemether
Dihydroartemisinin
What is Coartem
Artemether + Lumefantrine
How do the Artemisinins work
Bind Fe
Break down peroxide bridges
Create free radicals
Should not be used as monotherapy
Artemisinins
What are the Artemisinin AE
Neurotoxicity
QT prolongation
Do Artemisinins work on liver stage
No
What is the Halofantrine AE
Cardiac toxicity
How is Lumefantrine given
Only as Coartem
What is the Lumefantrine AE
QT prolongation (Clinically insignificant)
Why don’t you give Artemisinins for prophylaxis
Short t1/2