Antischistosomal Drugs

Question 1

Praziquantel - Class

Answer 1

Antischistosomal- 1st choice agent effective against all 3 strains of Schistosoma: S. mansoni, S. haematobium, and S. japonicum

Question 2

Species S.Mansoni - where geographically and anatomically?

Answer 2

South America, Africa, Middle East

Liver, spleen, GI

Question 3

Species S. Haematobium – where geographically and anatomically?

Answer 3

Africa, Middle East

Urinary & genital tracts

Question 4

Species S. Japonicum - where geographically and anatomically?

Answer 4

China, Philippines

Liver, spleen, GI

Question 5

What are the 3 parasites txed w/antischistosomal drugs?

Answer 5

S.Mansoni, S. Haematobium, S. Japonicum

Question 6

Praziquantel - MOA

Answer 6

Causes influx of Ca to produce contraction and paralysis of worm musculature

Question 7

Praziquantel - Tox

Answer 7

At higher drug levels tegumental damage by an influx of Ca.

Question 8

Praziquantel - SE

Answer 8

Dose related transient abdominal distress

Question 9

Metrifonate - Tx

Answer 9

Second choice for strain Schistosoma haematobium (only effective against this strain)

Question 10

Metrifonate - MOA

Answer 10

It must be activated to dichlorovos which inhibits acetylcholinesterase in the worm.

Question 11

Oxamniquine - Tx

Answer 11

Not effective against S. haematobium or S. japonicum but is used against S. mansoni (second choice therapy)

Question 12

Oxamniquine - MOA (2 steps)

Answer 12

1. An enzyme converts oxamniquine into an ester (acetate, phosphate, or sulfate)
2. The ester spontaneously dissociates and the resulting electrophilic reactant alkylates schistosome DNA.

Question 13

Which straid of Schistosoma has no second choice tx?

Answer 13

S. Japonicum