Antibiotics: Nitrofurantoin

Question 1

Indications of nitrofurantoin?

Answer 1

Acute, uncomplicated lower UTI

Prophylaxis of UTI

Question 2

Spectrum of activity of nitrofurantoin?

Answer 2

Works against most uncomplicated UTIs
e.g. E.coli (Gram-negative), Staph saprophyticus (Gram-positive)

Question 3

MOA of nitrofurantoin?

Answer 3

Metabolised (reduced) in bacterial cells by nitrofuran reductase.
→ its active metabolite damages bacterial DNA and causes cell death (bactericidal).

Question 4

Adverse effects of nitrofurantoin?

Answer 4

GI upset
- nausea
- diarrhoea​

Immediate and delayed hypersensitivity reactions. ​

​Can turn urine dark yellow/brown.

Chronic pulmonary reactions
Hepatitis
Peripheral neuropathy

In neonates, it can cause haemolytic anaemia.

Question 5

Warnings of nitrofurantoin?

Answer 5

Avoid in:
- pregnant women towards term
- babies in the first 3 months of age/life.
- renal impairment

Caution in:
- prophylaxis of UTIs (can increase risk of adverse effect, especially in elderly pts).

Question 6

Interactions of nitrofurantoin?

Answer 6

None significant

Question 7

Monitoring of nitrofurantoin?

Answer 7

For acute infection:
- improvement in signs/symptoms
- Investigations (e.g. fall in CRP/ESR, sterile urine on repeat culture)

For preventing recurrent UTI:
- improvement determined by frequency before and during prophylaxis.

Question 8

Pt education of nitrofurantoin?

Answer 8

Aims to get rid of infection and improve symptoms.

For prophylaxis, mention it is a long-term tx.

Check for nitrofurantoin allergy.

Advise urine colour may change to dark yellow/brown during tx -harmless and temporary.

Long term tx; report unexplained symptoms like pins and needles or breathlessness.