Makindo Medical Notes

💊 Pivmecillinam is an oral antibiotic with excellent efficacy for uncomplicated urinary tract infections (UTIs). It is particularly valuable because of its activity against some resistant organisms, including ESBL-producers.

📖 About: Always check the BNF link here for up-to-date prescribing advice.

• ✅ Licensed in the UK for acute uncomplicated cystitis.
• 💊 Belongs to the penicillin (β-lactam) group of antibiotics.
• 🦠 Active against Gram-negative organisms, including some ESBL-producing Enterobacterales.
• 📚 BNF is the gold standard for UK dosing and safety information.

⚙️ Mode of Action

• 🔬 A 6-aminopenicillanic acid derivative.
• 💊 Prodrug: Pivmecillinam → hydrolysed to mecillinam (the active antibacterial agent).
• 🧪 Binds to penicillin-binding protein 2 (PBP2) → inhibits bacterial cell wall synthesis.
• 💧 Highly concentrated in urine → ideal for UTIs.
• 👌 Generally well tolerated and usable in impaired renal function (but always check BNF for dose adjustments).

🎯 Indications & Typical Dosing

• 🚺 Acute uncomplicated cystitis (women): 400 mg stat dose, then 200 mg three times daily (TDS) until a total of 10 tablets taken.
• 🛁 Catheter-associated UTI: 400 mg stat, then 200 mg TDS for 7 days.

📊 Dose Range (BNF for confirmation)

🔄 Interactions

• 📌 See BNF for up-to-date interactions.

⚠️ Cautions

• 📌 Always see BNF. Take care in renal impairment (dose adjustment may be needed).

⛔ Contraindications

• 📌 See BNF. Usual penicillin contraindications apply (e.g. allergy).

💥 Side Effects

• 🌸 Vulvovaginal candidiasis (secondary fungal infection).
• 🧪 False-positive urinary glucose if tested with reducing substances.
• 😷 General β-lactam class risks: rash, diarrhoea, GI upset.

📚 References

• BNF: Pivmecillinam
• MHRA Drug Safety Update

📝 Revision Notes

• Think of pivmecillinam in women with resistant E. coli cystitis when trimethoprim or nitrofurantoin are unsuitable.
• Unusual in the UK until recently, but use is increasing with antimicrobial stewardship efforts.