8.3 Infection Management & Antimicrobial Stewardship

Common Community Infections: Empiric Choices and Durations

Empiric therapy follows the likely pathogens, local resistance patterns, allergy status, and patient factors such as pregnancy and renal function. Typical NICE-aligned first-line regimens to know for the exam:

• Community-acquired pneumonia (CAP): assess severity first — the CRB-65 score (confusion, respiratory rate, blood pressure, age 65 or over) guides whether the patient is managed in the community or admitted. Amoxicillin is first line for low-severity CAP; add or switch to a macrolide (clarithromycin) or doxycycline for atypical pathogens or penicillin allergy. Stop at 5 days when the patient is clinically stable, and advise that cough and fatigue can persist for weeks after the infection clears.
• Urinary tract infection (UTI): nitrofurantoin for 3 days is first line in non-pregnant women (avoid when eGFR is below 30, where it may fail and accumulate). Trimethoprim for 3 days is an alternative where local resistance is low. In pregnancy, use nitrofurantoin (avoided at term because of neonatal haemolysis risk), cefalexin, or amoxicillin-clavulanate guided by culture, typically for 7 days, and always send a urine culture. Reserve fluoroquinolones — routine empiric ciprofloxacin is discouraged because of rising resistance and serious adverse effects. Men with UTI need longer courses and investigation for underlying causes.
• Cellulitis: flucloxacillin covers the usual streptococci and Staphylococcus aureus; clarithromycin is the standard penicillin-allergy alternative. Mark the skin edge, elevate the limb, and review response at 48–72 hours.
• Sinusitis and acute otitis media are mostly viral and self-limiting: offer analgesia (paracetamol or ibuprofen) and saline, and use a delayed (back-up) prescription to be collected only if symptoms worsen or fail to settle; antibiotics are reserved for severe illness, symptoms lasting more than about 10 days without improvement, or bilateral otitis with discharge in young children, where amoxicillin for 5 days is typical. Sore throat is similarly usually viral — tools such as FeverPAIN or Centor criteria identify the minority who may benefit from phenoxymethylpenicillin.

Core Prescribing Principles

• Culture before antibiotic: obtain mid-stream urine, sputum, or blood cultures before the first dose whenever feasible, because cultures guide de-escalation — but never delay treatment in suspected sepsis, where every hour matters.
• Verify the allergy history: distinguish true allergy (urticaria, angioedema, anaphylaxis) from intolerance (nausea, diarrhoea, headache). Up to 90–95% of recorded penicillin allergy labels are not confirmed on formal assessment, and unverified labels push patients onto broader, costlier, and less effective agents. Document the drug, the reaction, its timing, and its severity.
• Renal dose adjustment: check renal function for renally cleared agents; recall nitrofurantoin is avoided below an eGFR of 30, and many beta-lactams need dose or interval changes in impairment.
• IV-to-oral switch criteria: the patient is afebrile and haemodynamically stable for 24–48 hours, tolerating oral intake with a functioning gastrointestinal tract, and clinically improving with falling inflammatory markers — then switch to a suitable oral agent. Agents with excellent oral bioavailability (for example fluoroquinolones, linezolid, or metronidazole) are particularly easy switches. Early switch shortens stay, reduces line infections, and cuts cost.

Antimicrobial Stewardship

Antimicrobial stewardship (AMS) means the right drug, at the right dose, by the right route, for the right duration, and it matters because antimicrobial resistance is a leading global health threat driven by unnecessary and inappropriate use:

• Start with the narrowest effective spectrum; de-escalate once culture and sensitivity results return, and build in an antibiotic review (time-out) at 48–72 hours for every inpatient prescription.
• Restrict broad-spectrum agents (carbapenems, piperacillin-tazobactam) to defined indications to preserve their utility.
• Prefer the shortest effective duration — for many common infections, 5 days is enough.
• C. difficile awareness: broad-spectrum exposure — especially clindamycin, cephalosporins, and fluoroquinolones — disrupts protective gut flora and predisposes to Clostridioides difficile infection; narrow agents and short courses limit this risk.
• Counsel every patient: take doses as directed, complete the course, do not share antibiotics, and do not keep leftovers. Practical points matter too — nitrofurantoin with food, doxycycline upright with plenty of water and sun protection.
• Vaccination as prevention: influenza and pneumococcal vaccination reduce infections and therefore antibiotic demand — stewardship starts before the first prescription.

The Pharmacist's Stewardship Role in the UAE

In the UAE, antibiotics are prescription-only medicines: dispensing any systemic antibiotic without a valid prescription is prohibited and actively enforced by health authorities (MOHAP, DHA, DOH), with penalties for non-compliant pharmacies. Community pharmacists act as gatekeepers — refusing non-prescription requests, verifying prescription validity, counseling on adherence, and redirecting patients with viral illnesses to symptomatic care and safety-netting advice. Hospital pharmacists contribute to antimicrobial stewardship programmes through formulary restriction, local guideline development, prospective audit and feedback, dose optimisation (renal adjustment and therapeutic drug monitoring), IV-to-oral switch prompts, and review of local antibiograms. Both roles are core examinable stewardship competencies.