Antimalarials

Question 1

When would you use clinical cure vs. radical cure for antimalarials?

Answer 1

• Clinical cure = blood schizonticides: can treat all 4 species
• Radical cure = tissue schizonticides: only treats P. vivax and P. ovale

Question 2

With ALL blood schizonticides, what toxicity should always be considered? Does this mean they should not be used as treatment?

Answer 2

Hemolytic anemia if G6PD deficient
- STILL USE though because RBC lysis occurs with malaria too and must be treated (G6PD deficiency often unknown, so rare)

Question 3

What is the recommended treatment for a pregnant female with malaria?

Answer 3

Use ONLY blood schizonticides until baby is born…

- Once delivered, can begin use of tissue schizonticides

Question 4

If the patient is a child, what antimalarial medication/treatment should NOT be considered?

Answer 4

Doxycycline

- No prophylaxis or Quinine + Doxycycline

Question 5

If a patient is traveling, what should be considered when choosing an antimalarial medication?

Answer 5

Is there Chloroquine resistance?

• If not, use Chloroquine
• If there is, choose a different option

Question 6

What is the DOC for malaria?

Answer 6

Chloroquine

Question 7

What is the MOA of Chloroquine?

Answer 7

Concentrates in food vacuoles of parasites within RBCs

Question 8

What are the three primary toxicities associated with Chloroquine?

Answer 8

• QT prolongation
• Retinal/corneal issues
• Hemolytic anemia in G6PD deficiency

Question 9

With what two conditions is Chloroquine contraindicated?

Answer 9

• Psoriasis

- Porphyria

Question 10

What drug is often combined with the antimalarials (never monotherapy), and why? With what two medications is it NOT combined?

Answer 10

ACT drugs extend drug half life

- NOT combined with Chloroquine or Quinine

Question 11

If a patient traveled to a Chloroquine resistant area, what two medications are recommended as alternatives (second line)?

Answer 11

• Atovoquone-Proguanil + ACT

- Lumefantrine + ACT

Question 12

In treatment of malaria, what two different medication combinations are examples of synergism (also have the same MOA, what is it)?

Answer 12

MOA: inhibit folic acid synthesis

• Atovoquone-Proguanil + ACT
• Pyrimethamine-Sulfadoxine + ACT

Question 13

What is the MOA for Atovoquone-Proguanil + ACT, and how does each medication contribute to this?

Answer 13

MOA: inhibit folic acid synthesis

• Atovoquone: inhibits ATP
• Proguanil: inhibits DHF → THF

Question 14

What is the MOA for Pyrimethamine-Sulfadoxine + ACT, and how does each medication contribute to this?

Answer 14

MOA: inhibit folic acid synthesis

• Pyrimethamine: inhibits DHF → THF
• Sulfadoxine: inhibits PABA

Question 15

What two antimalarial treatment options should be given with Leucovorin, and why?

Answer 15

Inhibit folic acid synthesis so need folic acid supplement

• Atovoquone-Proguanil + ACT
• Pyrimethamine-Sulfadoxine + ACT

Question 16

What is the primary toxicity associated with Lumefantrine + ACT?

Answer 16

QT prolongation

Question 17

When would you use Quinine vs. Quinidine for treatment of malaria? How is each administered?

What must these medications ALWAYS be combined with, and why?

Answer 17

• Quinine: oral, uncomplicated
• Quinidine: IV, complicated (i.e. coma)

Both are combined with either Tetracycline, Doxycycline or Clindamycin to reduce tx length and toxicities

Question 18

What is the primary toxicity associated with Quinine/Quinidine?

What toxicity is associated with ONLY Quinine?

Answer 18

• Quinine/Quinidine: QT prolongation

- Quinine ONLY: cinchonism

Question 19

What is the last resort option for treating malaria? Why is it the last option (think toxicities)?

Answer 19

Mefloquine + ACT

- VERY toxic (psychoses/vivid dreams)

Question 20

What is the ONLY purpose of using Pyrimethamine-Sulfadoxine + ACT?

Answer 20

PROPHYLAXIS in pregnancy

- Other blood schizonticides will work if active disease present

Question 21

What is the DOC for tissue schizonticides in treatment of malaria? When is use of this medication contraindicated?

What is the alternative option to this medication?

Answer 21

Primaquine
- Do NOT use if pregnant

Can use Tafenoquine but newer…