Folate Reductase Inhibitors (Trimethoprim)

Question 1

Mechanism

Answer 1

Inhibits dihydrofolate reductase, blocks formation of tetrahydrofolate (DNA synthesis inhibitor)

Question 2

TMP-SMX (co-trimoxazole)

Answer 2

higher abx activity and spectrum, less resistance encountered
Synergistic interaction

Question 3

Contraindications

Answer 3

pregnant women - may cause folate deficiency

Question 4

Clinical uses of trimethoprim

Answer 4

Weak base - useful in treating bacterial prostatitis (goes to acidic prostatic fluid)

Question 5

Clinical uses of TMP-SMX

Answer 5

Prevention and treatment of UTI caused by Family enterobaceriaceae (E. coli, K. pneumonia, Proteus, Enterobacter spp)
Also used to prevent and treat otitis media
Active against H. influ, M. catarrhallis, P. carinii, S. pneumonia