Anti-infectives (Inhibitors of Folate Synthesis)

Question 1

Examples of drug (Inhibitors of Folate Synthesis)

Answer 1

• Trimethoprim

Question 2

Mechanism of action (Inhibitors of Folate Synthesis)

Answer 2

• Inhibits folate metabolism pathway and leads to impaired nucleotide synthesis
• Therefore interferes with bacterial DNA replication.

Question 3

Indications (Inhibitors of Folate Synthesis)

Answer 3

• First line antibiotic in uncomplicated UTI.
• Acute / chronic bronchitis
• Pneumocystis pneumonia (PCP)
• Good range of action against gram negative and gram positive bacteria. Including some MRSA cover.

Question 4

Side effects (Inhibitors of Folate Synthesis)

Answer 4

• Elevated serum creatinine
• Hyperkalaemia
• Depressed haematopoiesis
• Rash and GI disturbance both relatively common

Question 5

Important pharmacokinetics/pharmacodynamics (Inhibitors of Folate Synthesis)

Answer 5

• Penetrates well into the prostate, suitable for men with uncomplicated UTI
• Avoid in the first trimester of pregnancy
• ## Resistant organisms are a major problem in clinical use.Hyperkalaemia is more common in patients with impaired renal function.

Question 6

Patient information (Inhibitors of Folate Synthesis)

Answer 6

• Blood tests required in those at risk of hyperkalaemia.
• Return to the doctor if symptoms do not clear after trimethoprim course, resistance does occur.
• Rash and GI disturbances are common adverse reactions.