Uncomplicated UTI in Adult Male i.e. no fever or flank pain

Comments from Expert Advisory Group

  • Always send pre-treatment MSU in males.
  • Empirical antibiotic choice should be tailored based on previous results (if available).
  • Consider Sexually Transmitted Infections particularly in young people presenting with lower urinary tract symptoms.
  • Consider acute prostatitis in males >50 years with lower urinary tract symptoms.
  • Nitrofurantoin should NOT be given if there is any suspicion of prostatitis.
  • It is advisable to refer men with recurrent UTI for specialist opinion. Antimicrobial prophylaxis should only be considered following specialist advice.
  • Consider acute pyelonephritis /upper UTI when:
    • Flank pain which radiates to the iliac fossa and suprapubic area.
    • Sudden onset general systemic disturbance with fever, rigors, vomiting.
    • Tenderness and guarding over the kidney.
    • Nausea and/or vomiting


Choice of empirical therapy should be governed by local resistance rates where available. Patterns can vary substantially across the country

(i.e. no fever or flank pain)
Drug Dose Duration Notes
1st Choice Options
Nitrofurantoin Immediate Release Capsules 50 mg every 6 hours

7 days

Nitrofurantoin has poor penetration in the prostate. Consider prostatitis as a diagnosis in males if symptoms persist.

Nitrofurantoin is NOT a suitable antibiotic choice for Upper UTI.

Nitrofurantoin is contraindicated in patients with eGFR < 30 mL/min/1.73 m2

Immediate/ Prolonged Release should be stated on the prescription (see note below on formulation difference)

Nitrofurantoin Prolonged Release Capsules

100 mg every 12 hours

7 days

Alternative 1st Choice Options (if nitrofurantoin unsuitable)


500 mg every 12 hours

7 days

Cephalosporins should not be used in severe penicillin allergy.



200 mg every 12 hours

7 days 

Use only when risk of resistance is low i.e. where previous culture suggests susceptibility (but trimethoprim was not used) or in younger patients without a significant antibiotic exposure history. Risk of resistance is more likely in older people in residential facilities. 

Some considerations for antibiotic choice:

Nitrofurantoin is the preferred first choice if it is not contra-indicated. Nitrofurantoin resistance rates remain low in community E.coli UTIs throughout Ireland (including in ESBL-producing isolates) despite increasing resistance to other antibiotics.

Nitrofurantoin precautions

  1. Tissue concentrations are too low for treatment of systemic infection, including pyelonephritis. It is only suitable for uncomplicated lower urinary tract infection and in lower CA-UTI where the patient is NOT systemically unwell.
  2. Nitrofurantoin has poor penetration in the prostate. Consider acute prostatitis as a diagnosis in males if symptoms persist.
  3. Nitrofurantoin should notbe used in patients with severe renal impairment (CKD Stage 4/5, eGFR <30 mL/min/1.73m2, Creatinine Clearance <30 mL/min) because of diminished urinary tract concentrations and increased risk of toxicity. Nitrofurantoin may be used with caution (as short-course therapy only) if there is a lesser degree of renal impairment (eGFR greater than 30 mL/min/1.73m2) to treat suspected or proven resistant pathogens, when the benefits are expected to outweigh the risks. In frail elderly patients with poor fluid intake and an infection, creatinine levels may deteriorate quickly so if a patient is dehydrated then established renal impairment may be further compromised.
  4. Two nitrofurantoin formulations are available: nitrofurantoin immediate release capsules (Macrodantin®) and nitrofurantoin prolonged release capsules (MacroBid®). For the treatment of infection the prolonged release MacroBid®capsules are dosed twice daily whilst the standard Macrodantin® capsules are dosed four times daily. As ADVANZ PHARMA is the sole supplier of these products in Ireland, a stock management plan has been introduced to ensure patients in Ireland have access to these important medicines. Should any customer have difficulty in getting supply, ADVANZ PHARMA have advised pharmacists to contact their customer service line on +353 15294230 to allow them to assist in meeting patients’ needs.

There is data to indicate that the rate of trimethoprim resistance in E.coli in community urinary samples is high in particular in older people in residential care facilities. Empiric trimethoprim is therefore no longer recommended except where nitrofurantoin is unsuitable and the risk of resistance is low (e.g. where a previous urine culture has had a trimethoprim-susceptible isolate and trimethoprim has not been used, or in a young patient without a significant antibiotic exposure history).

Fosfomycin is not licenced for the treatment of UTI in male patients.

Amoxicillin is not recommended as empiric therapy, as resistance rates in community E. coli UTIs are extremely high. Only use if amoxicillin susceptibility known.

Co-amoxiclav resistance in E. coli in community urine samples is high. In addition, it is a systemic agent and should be avoided in uncomplicated cystitis if a locally acting agent (e.g. nitrofurantoin) could be used instead.

Ciprofloxacin is a broad-spectrum antibiotic, associated with C. difficile infection and multiple adverse effects. It is not recommended for the empiric treatment of uncomplicated cystitis. It may be considered for targeted therapy of multi-resistant infections, where there areno other appropriate options.

Patient Information

The HSE Health A-Z website provides patient information on many conditions and treatments.

Safe Prescribing

Visit the safe prescribing page

  • Doses are oral and for adults unless otherwise stated
  • Fluoroquinolone warning
  • Penicillin allergy – tips on prescribing in penicillin allergy
  • Renal impairment dosing table
  • Drug interactions table. Extensive drug interactions for clarithromycin, fluoroquinolones, azole antifungals and rifampicin. Many antibiotics increase the risk of bleeding with anticoagulants.
  • Visit the Health Products Regulatory Authority (HPRA) website for detailed drug information (summary of product characteristics and patient information leaflets). Dosing details, contraindications and drug interactions can also be found in the Irish Medicines Formulary (IMF) or other reference sources such as British National Formulary (BNF) / BNF for children (BNFC).

Reviewed July 2023

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