Nitrofurantoin: Price, Dosage & Where to Buy

Nitrofurantoin is an antibacterial medicine most commonly used to treat acute uncomplicated bladder infections, also called acute cystitis, caused by susceptible bacteria. It requires a prescription in the United Kingdom and is available in oral capsule and liquid forms. Its use is limited to suitable urinary infections; it is not indicated for kidney infections or abscesses around the kidney.

Nitrofurantoin acts against susceptible bacteria by disrupting several processes they need to survive. Inside bacterial cells, it is converted into reactive substances that damage bacterial components and interfere with essential activities, including the production of proteins and genetic material.

This antibacterial action helps control a susceptible infection in the urinary tract. Its distribution into tissues is limited, which explains why the listed indication concerns uncomplicated bladder infections rather than kidney infections or abscesses around the kidney.

Nitrofurantoin monohydrate/macrocrystals capsules are indicated for acute uncomplicated urinary tract infections affecting the bladder, known as acute cystitis. The listed bacteria are susceptible strains of Escherichia coli and Staphylococcus saprophyticus. The medicine is not indicated for pyelonephritis, an infection of the kidney, or perinephric abscesses, which are collections of infection around the kidney.

Treatment should be limited to infections proven or strongly suspected to involve susceptible bacteria. Urine culture and susceptibility testing can help guide treatment selection. Bacteria may persist or reappear after treatment, and the label describes selecting another antibacterial medicine with broader tissue distribution if this happens.

The label lists oral capsules in strengths of 25 mg, 50 mg, and 100 mg. The label lists powder for oral suspension at 25 mg/5 mL and oral suspensions at 25 mg/5 mL and 50 mg/5 mL. The label lists a regimen for monohydrate/macrocrystals capsules in adults and paediatric patients over 12 years of one 100 mg capsule every 12 hours for seven days, with food.

This regimen relates specifically to the monohydrate/macrocrystals capsule formulation described in the label. A dosing regimen for the other capsule strengths or liquid formulations is not listed here. The prescription and dispensing label should be checked with a pharmacist if the formulation or directions are unclear.

The capsule label specifies storage at 20° to 25°C, with excursions permitted to 15° to 30°C. Keep medicines out of the sight and reach of children and follow the dispensing label to maintain quality.

A missed antibiotic dose can interrupt the intended treatment schedule. General pharmacy advice is to resume the prescribed schedule, avoiding a double dose to compensate for an omission. If the next scheduled dose is close, or the timing is uncertain, a pharmacist can advise based on the dispensing label.

Nitrofurantoin is contraindicated at term, defined as 38 to 42 weeks gestation, during labour and delivery, or when labour is imminent. This is because of the possibility of haemolytic anaemia related to immature red blood cell enzyme systems.

The label does not specify lactation information. Pregnancy or breastfeeding should be discussed with a doctor or pharmacist.