💊 Nitrofurantoin

Nitrofurantoin is a nitrofuran antibiotic, specifically used for the treatment and prophylaxis of uncomplicated lower urinary tract infections.

It is reduced by bacterial flavoproteins to reactive intermediates that damage bacterial DNA, RNA, and proteins. This broad-spectrum damage inhibits vital bacterial processes, leading to bactericidal activity.

Nitrofurantoin is a first-line agent for uncomplicated lower urinary tract infections (UTIs) in adults and children in the UK. It is also used for long-term prophylaxis of recurrent UTIs, particularly in women.

It is contraindicated in severe renal impairment (creatinine clearance <45 mL/min) due to reduced efficacy and increased systemic toxicity. It should not be used in term pregnancy (after 38 weeks) or in neonates due to the risk of haemolytic anaemia.

Common adverse effects include nausea, vomiting, and diarrhoea. Pulmonary reactions (acute or chronic) are serious but rare, presenting as cough, dyspnoea, or fever. Peripheral neuropathy and hepatotoxicity are also rare but serious adverse effects, especially with long-term use.

For short courses, routine monitoring is generally not required. For long-term prophylactic use, monitor renal function (urea and electrolytes) and liver function tests periodically. Advise patients to report any respiratory symptoms or numbness/tingling.

Always check renal function before prescribing, ensuring creatinine clearance is above 45 mL/min. Counsel patients that their urine may turn dark yellow or brown. Advise them to report any new or worsening cough, shortness of breath, or tingling sensations.

Nitrofurantoin is a common choice for uncomplicated UTIs due to low resistance rates. Its use is restricted to lower UTIs and contraindicated in significant renal impairment. Be aware of the rare but serious pulmonary and neurological adverse effects, particularly with long-term use.

SBAs frequently test the contraindication of nitrofurantoin in severe renal impairment. Questions may also focus on its use for lower UTIs only, or the rare but serious pulmonary adverse effects, especially with long-term use.