INFECTION: NITROFURANTOIN

Question 1

NITROFURANTOIN: INDICATIONS

Answer 1

• Uncomplicated lower urinary tract infection (UTI), as a first-line antibiotic (alternatives are trimethoprim, amoxicillin)
• Reaches theraputic concentrations in urine through renal excretion and is most bacteriacidal in acidic environments such as urine

Question 2

NITROFURANTOIN: MOA

Answer 2

• Nitrofurantoin is metabolised (reduced) in bacterial cells by nitrofuran reductase
• Its active metabolite damages bacterial DNA and causes cell death (bactericidal effect)
• Nitrofurantoin is active against the Gram-negative (e.g. Escherichia coli) and Gram-positive (Staphylococcus saprophyticus) organisms that commonly cause urinary tract infections

Question 3

NITROFURANTOIN: ADVERSE EFFECTS

Answer 3

• GI Upset
• Immediate and delayed HSRxns
• Can turn urine dark yellow/brown
• Chronic pulmonary rxns, hepatitis + peripheral neuropathy
• Neonates, Hemolytic Anaemia can occur as immature red blood cells are unable to mop up nitrafurotoin-stimulated super oxides which damage RBCs

Question 4

NITROFURANTOIN: WARNINGS

Answer 4

• Nitrofurantoin should not be prescribed for pregnant women towards term or for babies in the first 3 months of life
• It is contraindicated in patients with renal impairment, as impaired excretion increases toxicity and reduces efficacy due to lower urinary drug concentrations
• long-term prevention of UTIs, as chronic use increases the risk of adverse effects, particularly in elderly patients

Question 5

NITROFURANTOIN: INTERACTIONS

Answer 5

• NA