Bactrim

Sulfamethoxazole and Trimethoprim

Class

Sulfonamide & Folate antagonist

Dose

80/400 (SS)

160/800 (DS)

 

PJP; high dose eg 2xDS qid (or IV equivalent) 

PJP Prophylaxis M/W/F

Mechanism

Bactericidal

MoA

Blocks folic enzymes

Prevents bacterial cell synthesis

Time v Concentration

Time

Spectrum​

Covers

Doesn't Cover

Wide spectrum

G+

 

G-

E Coli

Klebsiella

Enterobacter

Salmonella

Shigella

Acenitobacter

 

Also

Pneumocystis jiroveci

Sternotrophomonas

Pseudomonas

Indications

PJP Tx & Prophylaxis

PK

A

100% OBA

D

Wide distribution PPB 40-70%

M

Metabolised by liver

E

Metabolites in urine by glom filtration & tubular secretion

A/E

Allergy to sulfa

Haem: Bone marrow suppression

Renal: Acute interstitial nephritis, ATN, Pseudo-Crt elevation (blocks Cr secretion into tubules and increases Cr 20%)

MetHb in G6PD deficiency

Transaminitis/cholestasis, pancreatitis

Monitoring

LFTs, Renal fn