Antimalarials

Question 1

How is Chloroquine administered?

Answer 1

Oral

Question 2

What is the MOA of Chloroquine?

Answer 2

Blood Schizonticide

Actively concentrated within plasmodia that reside within erythrocytes; May interfere with lysosomal degradation of Hb (reduces symptoms – “clinical cure”)

Question 3

What are the uses of Chloroquine?

Answer 3

DOC:
P. falciparum
P. malariae (if no resistance)

Question 4

What are the toxicities of Chloroquine?

Answer 4

• Accumulates in melanin-rich tissues: skin, retina (ototox)
• CNS (dizziness, HA, tinnitus)
• Hemolysis – use caution in G6PD deficient
• QT prolongation

Question 5

What are contraindications of Chloroquine?

Answer 5

• Ocular disease
• Psoriasis
• Porphyria

Question 6

How is resistance developed to Chloroquine?

Answer 6

Transport pumps

Question 7

How is Artesunate & Artemether administered?

Answer 7

Oral

Question 8

What are the uses of Artesunate & Artemether?

Answer 8

DOC:
Chloroquine resistant
P. falciparum
P. vivax

(must be used in combination with other antimalarials - “ACT”)

Question 9

What is the DOC for P. falciparum and P. malariae?

Answer 9

Chloroquine

Question 10

What is the DOC for uncomplicated Chloroquine resistant malaria?

Answer 10

ACT + Atovoquone-Proquanil

OR

ACT + Lumefantrine

Question 11

What is the 2nd DOC for uncomplicated Chloroquine resistant malaria?

Answer 11

Quinine + Doxy/Tetra/Clinda

Tetra is the preferred combo, but Clinda is used in children under 8 and pregnancy

Question 12

What is the MOA of Sulfadoxine-Pyrimethamine + ACT

Answer 12

Sulfa inhibits PABA into folic acid

Pyrimethamine inhibits DHFR, blocking conversion of DHF to tetrahydrofolic

Question 13

What is the use of Sulfadoxine-Pyrimethamine + ACT?

Answer 13

Prophylaxis treatment of malaria in pregnant women who reside in areas where malaria is epidemic.

DO NOT give in a pregnant woman who has active disease

Question 14

How is resistance acquired against Sulfadoxine-Pyrimethamine?

Answer 14

Mutation in DHFR

Question 15

What is the MOA for Atovaquone-Proquanil + ACT?

Answer 15

Atovaquone – interferes with mitochondrial electron transport and ATP pyrimidine biosynthesis

Proquanil – prodrug; converted to cycloguanil – DHFR inhibitor

Synergistic combo – effective in regions where Chloroquine resistance is high

Combined with Artesunate for rapid clearance and decrease in resistance

Question 16

What are the uses of Atovaquone-Proquanil + ACT?

Answer 16

Uncomplicated chloroquine-resistant malaria

Prophylaxis against chloroquine-resistant P. falciparum

Question 17

What are the toxicities of Atovaquone-Proquanil + ACT?

Answer 17

• Rash, fever

- Vomiting and diarrhea reduce absorption and efficacy, so must be discontinued

Question 18

What are the toxicities of Artemether + Lumefantrine?

Answer 18

• Headache

- QT prolongation

Question 19

What is the DOC for complicated Chloroquine-resistance malaria?

Answer 19

Quinidine + Tetra/Doxy/Clinda

Tetra is the preferred combo, but Clinda is used in children under 8 and pregnancy

Question 20

How is Quinine and Quinidine Gluconate administered?

Answer 20

Quinine (oral); Quinidine (IV)

Given in combination with Doxy, Tetra, or Clinda

Tetra is the preferred combo, but Clinda is used in children under 8 and pregnancy

Question 21

What are toxicities of Quinine and Quinidine Gluconate?

Answer 21

• Cinchonsim – tinnitus, HA, dizziness, flushing, visual disturbances
• Antiarrhythmic agent – Class 1A
• QT elongation
• Diarrhea
• Hemolysis in G6PD deficiency
• Stimulates insulin release (caution in those with hypoglycemia)

Question 22

What are the uses of Mefloquine + ACT?

Answer 22

Uncomplicated Chloroquine-resistant plasmodia, but only as a LAST RESORT

Question 23

What are toxicities of Mefloquine + ACT?

Answer 23

• Depression of myocardium
• Seizures
• May aggravate latent psychoses
• Vivid dreams
• Teratogenic

Question 24

What are contraindications to using Mefloquine + ACT?

Answer 24

• Pregnancy
• History of mental illness
• Epilepsy

Question 25

What drug should not be given with Mefloquine and why?

Answer 25

Do not give with Quinine due to both having cardiac toxicity

Question 26

What is the MOA for Primaquine?

Answer 26

Tissue Schizonticide Eliminate plasmodia from tissue and acts on hepatic stages (exoerythrocytic) – Eliminates dormant phase to prevent relapse – “radical cure"

Question 27

What are the uses of Primaquine?

Answer 27

Radical cure of P. vivax and P. ovale

Question 28

What are toxicities of Primaquine?

Answer 28

- Hemolysis in G6PD deficiency (use low dose once daily x 8 wks) - Fetal hemolytic anemia - Teratogenic

Question 29

What are contraindications of Primaquine?

Answer 29

- Pregnancy, breastfeeding - Infants < 6 months - SLE, RA

Question 30

What is the MOA of Tafenoquine?

Answer 30

Tissue Schizonticide Eliminate plasmodia from tissue and acts on hepatic stages (exoerythrocytic) – Eliminates dormant phase to prevent relapse – “radical cure"

Question 31

What are the uses of Tafenoquine?

Answer 31

Prophylaxis ( > 18 years old) Radical cure of P. vivax and P. ovale ( > 16 years old)

Question 32

What are toxicities of Tafenoquine?

Answer 32

- Back pain, HA - Keratopathy - Teratogenic

Question 33

What are contraindications of Tafenoquine?

Answer 33

- G6PD deficiency or unknown G6PD status | - Pregnancy

Question 34

What are the uses of Quinine?

Answer 34

Uncomplicated Chloroquine-resistant plasmodia