Summary of recommendations for initial treatment of commonly encountered infections

Antibiotics Guidelines - SUMMARY
A summary of recommendations for the initial treatment of commonly encountered infections
Please see full guidelines on Trust intranet for further details
Vulnerable elderly patients are those who are frail, housebound, or from nursing or residential homes Doses quoted are based on normal renal and hepatic function. Modify doses in patients with renal or hepatic impairment. Specify the indication and duration of therapy or a review date for all antibiotic prescriptions in the notes and on the drug chart
Check previous microbiology results on iCM prior to starting antibiotics in case of infection due to resistant organism
First choice
Alternative / comments
Respiratory system
Community-acquired pneumonia
Mild severity – oral
(CURB-65 score 0–1) Amoxicillin 500 mg three times a day by mouth for 5 days
Clarithromycin 500 mg twice daily by mouth for 5 days
Vulnerable elderly: Doxycycline 200 mg stat then 100 mg once daily by mouth for 5 days
Amoxicillin 500 mg three times a day by mouth +/- clarithromycin
Doxycycline 200 mg stat then 100 mg once daily by mouth for 7 days
Moderate severity – oral 500 mg twice daily by mouth for 7 days
(CURB-65 score = 2) Stop clarithromycin after 48 hours if unilateral pneumonia
If a concurrent urine infection is suspected, add gentamicin IV* stat
If a concurrent urine infection is suspected, add gentamicin IV* stat
Vulnerable elderly: Doxycycline 200 mg stat then 100 mg once daily by mouth for 7 days. If IV required, discuss with microbiology.
High severity – IV initially Benzylpenicillin 1.2 g four times a day intravenously plus
Vancomycin intravenously** plus clarithromycin 500 mg twice daily IV for 7–10
(CURB-65 score ≥3) clarithromycin 500 mg twice daily intravenously for 7–10 days
daily If S. aureus or Gram negatives suspected, discuss with microbiology
If S. aureus or Gram negatives suspected, discuss with microbiology Infective exacerbation of
Previous doxycycline exposure: amoxicillin 500 mg three times a day by mouth for
Doxycycline 200 mg stat then 100 mg once daily by mouth for 5 days
COPD – oral
Amoxicillin 1 g three times daily by mouth or benzylpenicillin 1.2 g
Aspiration pneumonia four times daily intravenously for 5 days
Clarithromycin 500 mg twice daily by mouth or intravenously for 5 days
Metronidazole is not required
Metronidazole is not required
Hospital-acquired pneumonia
Early onset (<5 days after
Doxycycline 200 mg stat then 100 mg once daily by mouth for 5 days
IV only if unable to tolerate oral Amoxicillin 500 mg three times a day intravenously plus trimethoprim Clarithromycin 500 mg twice daily intravenously plus trimethoprim 200 mg twice
antibiotics 200 mg twice daily by mouth for 5 days Late onset (>5 days after Piperacillin/ tazobactam 4.5 g three times a day intravenously for
Meropenem 500 mg four times a day intravenously for 5 days
admission), or high severity 5 days
Investigate history of penicillin allergy before prescribing early onset Switch to oral antibiotics once improving clinically
Switch to oral antibiotics once improving clinically Genitourinary tract
Trimethoprim 200 mg twice daily by mouth for 3 days (women) or
Nitrofurantion 100 mg four times a day by mouth for 5 days (women) or 7 days
Uncomplicated UTI – oral 7 days (men) or
Review urine culture results Cefalexin 500 mg three times a day by mouth for 3 days (pregnant
(Avoid nitrofurantion if eGFR is less than 50 ml/min) Uncomplicated UTI – oral Pivmecillinam 400 mg stat then 200 mg three times a day by mouth for
Contact microbiology if penicillin allergic or complicated infection such as (ESBL producing organism) 3 days (women) or 7 days (men) Gentamicin once daily intravenously* for 24–48 hours followed by
Gentamicin once daily intravenously* for 24–48 hours followed by ciprofloxacin
Pyelonephritis – IV initially co-amoxiclav 625 mg three times a day by mouth to complete
500 mg twice daily by mouth to complete 7–10 day total course Vulnerable elderly: gentamicin intravenously* stat. Subsequent doses at discretion of the consultant
Asymptomatic: no antibiotics required Do not treat if asymptomatic as all catheters become colonised with bacteria. Catheter UTI
Urine dipstick is meaningless; urine culture unreliable: do not use to guide Symptomatic: gentamicin once daily intravenously* for 5 days
Elderly: give a stat dose; subsequent doses at consultant discretion treatment. Remove infected catheter where possible. Clostridium difficile infection
Stop other antibiotics if clinical y possible Mild disease Metronidazole 400 mg three times a day by mouth for 14 days
Stop any laxatives; review need for proton pump inhibitors if taking them Moderate/severe disease or Vancomycin 125–500 mg four times a day by mouth or nasogastric
Urgent gastroenterology/surgical review if severe disease significant co-morbidities tube for 14 days Gastroenteritis No antibiotics
Gentamicin once daily intravenously* plus co-amoxiclav 1.2 g three
Cholecystitis/ cholangitis/ times a day intravenously
Gentamicin once daily intravenously* plus ciprofloxacin 200 mg twice daily
diverticulitis/ peritonitis
intravenously (500 mg twice daily by mouth) plus metronidazole 500 mg three
co-amoxiclav 625 mg three times a day by mouth as soon as
times a day intravenously (400 mg three times a day by mouth) Systemic infections
Meningitis

Ceftriaxone can be used in penicillin allergy, unless previous anaphylaxis (see
Aged less than 50 years Ceftriaxone 2 g twice daily intravenously for 14 days
Management of Penicillin Allergy in Adults policy on Trust intranet) Aged 50 years and over Ceftriaxone 2 g twice daily intravenously plus amoxicillin 2 g four
Septicaemia/ sepsis syndrome
Amoxicillin 1 g three times a day intravenously plus metronidazole
Seek microbiology advice for penicillin allergic patients, patients who are severely ill Unknown source 500 mg three times a day intravenously plus gentamicin once daily
or who are failing to respond to treatment Seek microbiology advice for patients who are severely ill or who are failing to MRSA colonised Vancomycin intravenously** plus metronidazole 500 mg three times a
day intravenously plus gentamicin once daily intravenously*
respond to treatment Seek microbiology advice for penicillin allergic patients, patients who are severely ill Previously ESBL positive Meropenem 500 mg four times a day intravenously plus amikacin
15 mg/kg stat intravenously (max dose 1.5 g) or who are failing to respond to treatment Neutropenic sepsis Piperacillin/ tazobactam 4.5 g three times a day intravenously plus
Meropenem 500 mg four times daily intravenously plus gentamicin once daily
gentamicin once daily intravenously*
Cellulitis
Mild/ Moderate Flucloxacillin 1 g four times daily by mouth for 7–14 days
Clindamycin 450 mg four times daily by mouth for 7–14 days
Flucloxacillin 2 g four times daily intravenously for 14 days
Clindamycin 600 mg four times daily intravenously for 14 days. Switch to oral
clindamycin 600 mg four times daily intravenously or
clindamycin after 24-48 hours as 100% bioavailable.
Meropenem 500 mg four times daily intravenously plus clindamycin
Ciprofloxacin 400 mg twice daily intravenously plus clindamycin 600 mg four
Necrotising fasciitis 600 mg four times daily intravenously times daily intravenously plus vancomycin intravenously**
This is a surgical emergency – seek senior review and microbiology advice urgently
Mild/Moderate Doxycycline 200 mg stat then 100 mg once daily by mouth for 7–14 days
Severe Vancomycin intravenously** for 14 days
Review the duration, need for the IV route and the indication for antibiotics in light of the clinical picture and microbiology results within 48 hours.
*gentamicin for details on prescribing and monitoring. Give 5 mg/kg lean body weight if creatinine clearance over 30 ml/min. If creatinine clearance is less than
30 ml/min, use 3 mg/kg once daily. Maximum daily dose of gentamicin is 480 mg. Check pre-dose levels before second dose due. Aim for a pre-dose level of less than 1 mg/L.
**Prescribe a single loading dose of vancomycin based on actual body weight: less than 60 kg give 1 g; 60-90 kg give 1.5 g; greater than 90 kg give 2 g. Base subsequent doses on renal function.
for full details.
Drugs marked in red contain penicillin and are contra-indicated in penicillin allergy; drugs marked in orange can cause allergic reactions in penicillin allergic patients, and must be avoided if there is
any history of anaphylaxis to penicillin; drugs marked in green are safe in penicillin allergy.y on Trust intranet for full details.
Date: December 2009
Version: 2
Updated: November 2011
Review date: November 2013
Person responsible for this guideline: Conor Jamieson, Pharmacy Team Leader-Antimicrobial Therapy

Source: http://bmec.swbh.nhs.uk/wp-content/uploads/2013/03/SYSTEMIC-ANTIBIOTICS.pdf