Antibiotic Guidelines

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Antibiotic Guidelines

Infection Management Guidelines Empirical Antibiotic Therapy in Adults

STOP AND THINK BEFORE ANTIBIOTIC THERAPY: 1 in 5 antibiotic courses associated with adverse events, including C.difficile, drug interactions/ toxicity, device-related infections and S. aureus bacteraemia.
THINK SEPSIS if NEWS ≥ 5. Send samples to microbiology before starting antibiotics.
RECORD antibiotic indication.
REVIEW patients and results.
RECORD clinical response and prescription daily.
Can you SIMPLIFY, SWITCH or STOP?
If Clinical improvement + eating/drinking + deep seated/complex infection not suspected.
IVOST and RECORD duration of remaining oral therapy.
RECORD the STOP date for oral antibiotics – score the appropriate date.
REVIEW all IV antibiotics DAILY and RECORD review date.
INFORM patient of the reason for the antibiotic and likely duration.

Definition of SEPSIS:

INFECTION (includes Systemic Inflammatory Response Syndrome (SIRS*).
WITH evidence of ORGAN HYPOPERFUSION (≥ 2 of Confusion, < 15 GCS or Resp Rate ≥ 22/ min or Systolic BP ≤ 100 mm Hg).
Ensure SEPSIS 6 within one hour:

Blood cultures (& any other relevant samples)
IV Antibiotic administration
Oxygen to maintain target saturation
Measure lactate,
IV fluids,
Monitor urine output hourly.

*SIRS indicated by Temp < 36°C or > 38°C, HR > 90 bpm, RR> 20/ min & WCC < 4 or > 12 x109/ L.
The SIRS is not specific to bacterial infection (also viral & non-infective causes).

Antibiotic Guidelines

Infective Exacerbation COPD and Antibiotic Guidelines

Only if purulent sputum (send for culture along with viral gargle)
Dual antibiotic therapy is not recommended & increases the risk of harm
Oral ▲Doxycycline 200mg as a one-off single dose then 100mg daily or Oral Amoxicillin 500mg 8 hourly or Oral ■ Clarithromycin 500mg 12 hourly
Duration 5 days

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Antibiotic Guidelines

Suspected COVID-19 pneumonia

Antibiotics NOT usually required
Antibiotics only if COPD with purulent sputum (treat as above) or suspected bacterial pneumonia with Chest X-Ray changes (treat as Pneumonia below)
Consider stopping antibiotics following review and positive SARS-CoV-2 result

Uncertain if LRTI/ UTI

Send MSSU, sputum and viral gargle
Oral Co-trimoxazole 960mg 12 hourly or Oral ▲Doxycycline 100mg 12 hourly
Do NOT prescribe Co-amoxiclav
Review/ clarify diagnosis at 48 hours
Duration if a diagnosis remains uncertain MAXIMUM 5 days

Pneumonia – Community-Acquired Pneumonia (CAP)

Assess for SEPSIS
Calculate CURB 65 score:
- Confusion (new onset)
- Urea > 7 mmol/L
- RR ≥ 30 breaths/ min
- BP – diastolic ≤ 60 mmHg or systolic < 90 mmHg
- Age ≥ 65 years

Non-severe CAP

CURB 65 score: ≤ 2 (and no sepsis)
Oral Amoxicillin 500mg 8 hourly or Oral ▲Doxycycline 200mg as a one-off single dose then 100mg daily or Oral ■ Clarithromycin 500mg 12 hourly
Duration 5 days

Severe CAP

CURB 65 score ≥ 3 or CAP (with any CURB 65 score) PLUS sepsis syndrome:
IV/oral ■ Clarithromycin 500mg 12 hourly PLUS either: IV Amoxicillin 1g 8 hrly or if requiring HDU/ ICU level care
IV Co-amoxiclav 1.2g 8 hrly
If true penicillin/beta-lactam allergy or Legionella strongly suspected
Oral/IV ■ Levofloxacin 500mg 12 hourly monotherapy (NB oral bioavailability 99 – 100 %)
Duration 5 days (IV/oral)
Legionella 10-14 days

Hospital Acquired Pneumonia (HAP)

Diagnosis of HAP is complex, and it is often over-diagnosed. Consider other causes of clinical deterioration, including hospital-onset COVID-19, and review diagnosis early.
Seek senior advice. Assess severity based on the CURB 65 score.
If within four days of admission. Treat as for CAP
If ≤ 7 days post-hospital discharge or ≥ 5 days after admission:

Non-severe HAP

Oral therapy recommended
Oral ▲Doxycycline 100mg 12 hourly
or Oral Co-trimoxazole 960mg 12 hourly
Duration 5 days

Severe HAP

IV Co-trimoxazole 960mg 12 hourly (or if allergy IV Co-amoxiclav 1.2g 8 hrly) + IV Gentamicin**∆ (max 4 days)
See BNF for dosing of co-trimoxazole in renal impairment if eGFR < 20 mL/min/ 1.73 m2 contact infection specialist
Duration 5 days (IV/oral)
If critically ill, discuss with an infection specialist

Aspiration pneumonia

This is a chemical injury and does not indicate antibiotic treatment.
Reserve antibiotics for those who fail to improve within 48 hrs post aspiration.
IV Amoxicillin 1g 8 hrly or if true penicillin/beta-lactam allergy
IV ■ Clarithromycin 500mg 12 hourly + IV Metronidazole 500mg 8 hourly
Duration 5 days (IV/oral)

Antibiotic Guidelines

Mild skin/soft tissue infection

Oral Flucloxacillin 1g 6 hrly or if true penicillin/beta-lactam allergy
Oral Co-trimoxazole 960mg 12 hourly or Oral ▲Doxycycline 100mg 12 hourly
Duration 5 days

Moderate / Severe Cellulitis

Consider OPAT/ ambulatory care (consult local management pathway).
If requires inpatient management: IV Flucloxacillin 2g 6 hrly
If MRSA is suspected or if true penicillin/ beta-lactam allergy
IV Vancomycin**
If rapidly progressive, Add IV Clindamycin 600mg 6 hourly
Duration 7-10 days (IV/oral)

Suspected Necrotising Fasciitis

Consider SSTI with disproportionate pain or acute organ dysfunction/ hypoperfusion, including hypotension.
Seek urgent surgical/orthopaedic review.
Urgent DEBRIDEMENT/ EXPLORATION may be required
IV Flucloxacillin 2g 6 hrly + IV Benzylpenicillin 2.4g 6 hrly + IV Metronidazole 500mg 8 hrly + IV Clindamycin 1.2g 6 hrly + IV Gentamicin**∆ (max 4 days)
If MRSA is suspected or if true penicillin/beta-lactam allergy
REPLACE Flucloxacillin + Benzylpenicillin with IV Vancomycin**
Rationalise therapy within 48-72 hours
Based on: response, microbiology results, infection specialist review
Duration 10 days (IV/oral) or as per infection specialist

Infected human/animal bite

Non-severe bite

Oral Co-amoxiclav 625mg 8 hrly or if true penicillin/beta-lactam allergy Oral ▲Doxycycline 100mg 12 hrly + Oral Metronidazole 400mg 8 hrly
Duration 5 days (treatment) 3 days (prophylaxis)

Severe bite

Consider surgical review.
IV Co-amoxiclav 1.2g 8 hrly or if true penicillin/beta-lactam allergy
IV Vancomycin** + Oral Metronidazole 400mg 8 hourly + Oral ▲■Ciprofloxacin 500mg 12 hourly
Duration 7 Days (IV/oral)

Antibiotic Guidelines

Gastroenteritis

Confirm travel history/ other risk factors
Antibiotics are not usually required and may be deleterious in E.coli O157
Consider viral causes, including COVID-19

difficile infection (CDI)

See NHS GGC CDI guidance
Treat before lab confirmation if suspected. Discontinue if toxin negative

No severity markers

Oral Metronidazole 400mg 8 hrly
(Do not use suspension)

Any severity marker or first recurrence of CDI

Oral Vancomycin 125mg 6 hourly
Duration 10 days
If enteral feeding tube use Vancomycin (see complete NHS GGC CDI guidance)

Intra-abdominal sepsis

IV Amoxicillin 1g 8 hrly + IV/Oral Metronidazole 500/400mg 8 hrly + IV Gentamicin**∆ (max 4 days) )
If eGFR < 20 mL/min/1.73 m2 IV Piperacillin/Tazobactam 4.5g 12 hourly (Monotherapy)
If true penicillin/beta-lactam allergy IV Vancomycin ** + IV/Oral Metronidazole 500/400mg 8 hourly + IV Gentamicin**Δ (max 4 days)
If eGFR < 20mL/min/1.73 m2 ▲■ IV/Oral Ciprofloxacin + IV/Oral Metronidazole 500/400mg 8 hrly
Total Duration 5 days (IV/oral)
Assuming source control

Biliary tract infection

As above, except metronidazole is not routinely required unless severe

Pancreatitis

Does not require antibiotic therapy unless complicated by cholangitis.

Spontaneous bacterial peritonitis

Ascites PLUS peritoneal white cell count > 500/mm3 or > 250 neutrophils/mm3
If not receiving co-trimoxazole prophylaxis: IV/Oral Co-trimoxazole 960mg 12 hourly
If receiving co-trimoxazole prophylaxis: IV Co-amoxiclav 1.2g 8 hrly or if true penicillin/beta-lactam allergy
Oral /IV▲■Ciprofloxacin 500/400mg 12 hourly + IV Vancomycin**
Duration 7 days (IV/oral)

Decompensated Chronic liver Disease with Sepsis Unknown Source

IV Piperacillin/Tazobactam 4.5g 8 hourly or, if true, penicillin/beta-lactam allergy
Oral /IV▲■Ciprofloxacin 500/400mg 12 hourly + IV Vancomycin**
Duration 7 days (IV/oral)

Antibiotic Guidelines

UTI in Pregnancy

See NHS GGC Obstetric guidance

Lower UTI/cystitis

Don’t treat asymptomatic bacteriuria.
Obtain urine culture before antibiotic.
In women often self-limiting, consider delayed prescribing.
Antibiotics if significant symptoms Oral Nitrofurantoin 50mg 6 hourly or Oral Trimethoprim 200mg 12 hourly
Duration: Females 3 days, Males 7 days
If eGFR < 30 mL/min/1.73 m2
- Nitrofurantoin contraindicated
- Trimethoprim use with caution may increase K+ and decrease renal function. Monitor

Upper UTI

Obtain urine for culture before antibiotic. Exclude pneumonia if loin/back pain

Non-severe/without sepsis

Oral▲■Ciprofloxacin 500mg 12 hourly or Oral Trimethoprim 200mg 12 hourly if sensitive organism.
Duration 7 days
Trimethoprim see above re lower eGFR

UROSEPSIS/ Pyelonephritis with fever

IV Gentamicin**∆ (max 4 days) If eGFR < 20 mL/min/1.73 m2 Oral ▲■Ciprofloxacin
Duration 7 days

Catheter-related UTI

Remove/ replace catheter and send urine for culture. Don’t treat asymptomatic bacteriuria

Symptomatic bacteriuria without sepsis

Give a single dose of IV Gentamicin**∆ immediately before catheter removal, or if the IV route is unavailable, give a single dose of oral ▲■Ciprofloxacin 500mg 30 minutes before catheter change. If eGFR 10-30 mL/min/1.73 m2 ▲■Ciprofloxacin 500mg single dose

Symptomatic bacteriuria with sepsis

As above and treat as per pyelonephritis/ culture results.
Duration 7 days (IV/oral)

Suspected prostatitis

Consider in all men with lower UTI symptoms
Refer to Urology
Oral ▲■Ciprofloxacin 500mg 12 hourly or Oral Trimethoprim 200mg 12 hourly if sensitive organism.
Duration 14 days

Septic arthritis/ Osteomyelitis Prosthetic joint infection

Obtain blood cultures before antibiotic therapy. If not acutely unwell/septic, obtain synovial fluid/deep tissue samples before antibiotic treatment.

Native joint

IV Flucloxacillin 2g 6 hrly If MRSA suspected or if true penicillin/beta-lactam allergy
IV Vancomycin**
If considered high risk for Gram-negative infection, e.g. immunocompromised, recurrent UTI or sickle cell disease
ADD IV Gentamicin**∆ (max 4 days)
Duration and IVOST: discuss with microbiology at 72 hours. Usually, 4 – 6 weeks (IV/oral) if the diagnosis is confirmed.

Prosthetic joint

IV Vancomycin** + IV Gentamicin**∆ (max 4 days)
Duration and IVOST: discuss with a microbiologist at 72 hours

Diabetic foot infection/ osteomyelitis

Assess ulcer size, probes to the bone, neuropathy, peripheral vascular disease, and MRSA risk. For outpatient therapy, consult diabetic clinic guidelines IV Flucloxacillin 2g 6 hrly + IV/Oral Metronidazole 500/400mg 8 hourly. If SEPSIS or SIRS ≥2, Add IV Gentamicin**∆ (max four days)
If MRSA is suspected or if true penicillin/beta-lactam allergy
IV Vancomycin** + IV/Oral Metronidazole 500/400mg 8 hourly
If SEPSIS or SIRS ≥2, Add IV Gentamicin**∆ (max four days) (Metronidazole oral bioavailability 80- 100%)
If eGFR < 20 mL/min/1.73 m2
REPLACE Gentamicin with Oral/IV ▲■Ciprofloxacin
Duration/IVOST Discuss with Micro/ID

Vascular graft infection

IV Flucloxacillin 2g 6hrly + IV Gentamicin**∆ (max four days)
If MRSA is suspected or if true penicillin/beta-lactam allergy
IV Vancomycin** + IV Gentamicin**∆ (max 4 days)
Discuss duration/IVOST further management with an Infection specialist

Antibiotic Guidelines

Urgent Blood Cultures, then IV Antimicrobial Therapy within ONE hour.

LP safe without CT scan UNLESS: seizures, GCS ≤ 12, CNS signs, papilloedema or immunosuppression. If CT: Blood cultures and antibiotics BEFORE CT scan.
Use Meningitis/ Encephalitis order set on Trakcare, Blood and CSF Glucose. LP contraindicated if Brain shift, rapid GCS reduction, Resp/ cardiac compromise, severe sepsis, rapidly evolving rash, infection at LP site, coagulopathy, thrombocytopenia, anticoagulant drugs

Antibiotic Guidelines and Possible bacterial meningitis

IV Ceftriaxone 2g 12 hrly
or if true penicillin/beta-lactam allergy
IV Chloramphenicol 25mg/kg (max 2g) 6 hrly
If age ≥ 60 years, immunosuppressed, pregnant, alcohol excess, liver disease or if listeria meningitis suspected: ADD IV Amoxicillin 2g 4 hrly to Ceftriaxone
or if true penicillin/beta-lactam allergy
ADD IV Co-trimoxazole 30mg/kg 6 hrly to Chloramphenicol
IF BACTERIAL MENINGITIS STRONGLY SUSPECTED ADD IV Dexamethasone 10mg 6 hourly (for four days) and referred to ID
Duration of antibiotics: Discuss with Micro/ID

Possible viral meningitis

Usually diagnosed after empirical management and exclusion of bacterial meningitis. Viral meningitis does NOT require antiviral prescription unless immunocompromised. Discuss with ID.
Confusion or reduced consciousness = Encephalitis, NOT meningitis

Possible viral encephalitis

Consider if confusion or reduced level of consciousness in suspected CNS infection. Ensure CSF viral PCR is requested. It may not be possible to differentiate it from bacterial meningoencephalitis. IV Aciclovir 10mg/kg 8 hrly
See BNF for dosing in renal impairment.
Discuss further management with ID/ virology. It may require repeat LP or neuro-imaging to establish the diagnosis.
Duration: Discuss with ID

Antibiotic Guidelines

Urgent Blood Cultures, then IV Antimicrobial Therapy within ONE hour.

Community or Healthcare-associated sepsis was source unknown

Review all anatomical systems, perform CXR and consider other imaging/ laboratory investigations
Consider and test for COVID-19
Review diagnosis DAILY
Add cover for S.aureus infection if; healthcare-associated, recent hospitalisation, post-op wound/ line related, PWID
Add cover for MRSA infection if; a recent MRSA carrier or previous infection
Add cover for Streptococcal infection if; pharyngitis/erythroderma/hypotension

Source unknown

IV Amoxicillin 1g 8 hrly + IV Gentamicin**∆ (max four days)
If S.aureus suspected
ADD IV Flucloxacillin 2g 6 hrly
If MRSA is suspected or if true penicillin/ beta-lactam allergy
IV Vancomycin** + IV Gentamicin**∆ (max 4 days)
If severe Streptococcal infection suspected
ADD IV Clindamycin 600mg 6 hourly
If eGFR < 20 mL/min/1.73 m2 REPLACE
Gentamicin with Oral/IV ▲■Ciprofloxacin
Duration: Review with response/ micro results at 72 hours

Possible Infective Endocarditis

Always seek senior specialist advice and refer to cardiology.
Native heart valve
IV Amoxicillin 2g 4 hrly + IV Flucloxacillin 2g 6 hrly if < 85kg (4 hrly if ≥ 85kg) + IV Gentamicin ∆ ( # synergistic dosing)
If MRSA/ resistant organisms are suspected or if true penicillin/beta-lactam allergy
IV Vancomycin** + IV Gentamicin ∆ (# synergistic dosing)

Prosthetic heart valve

IV Vancomycin** + IV Gentamicin ∆ (# synergistic dosing)
Discuss with Infection specialist within 72 hours
# See Synergistic Gentamicin for Endocarditis in Adults guideline on StaffNet for dosing

Antibiotic Guidelines

Urgent Blood Cultures then IV Antimicrobial Therapy within ONE hour

Immunocompromised Patient

Chemotherapy < 3 weeks, high dose steroids (e.g. prednisolone > 15mg/day for > 2 weeks), other immunosuppressants (e.g. anti-TNF, cyclophosphamide), Stem cell/solid organ transplant or primary immunodeficiency

Neutropenic Sepsis

Neutrophils ≤ 0.5 x 109 / L + fever (temperature > 38°C or 37.5°C on 2 occasions 30 min apart) / hypothermia < 36°C OR chills, shivers, sweats or other symptoms suggestive of infection.
All patients who have received recent chemotherapy and exhibit any of the symptoms above are presumed neutropenic and septic.

Immunocompromised with fever BUT normal neutrophils AND source of infection identified

Manage as per infection management guidelines based on the anatomical source.

Neutropenic sepsis or Immunocompromised with fever and source of infection unknown;

(See guideline Initial Management of Neutropenic Sepsis or Sepsis of Unknown Source in Immunocompromised Adults)

NEWS ≤ 6 Standard Risk

IV Piperacillin/Tazobactam 4.5g 6 hourly
If MRSA colonised/ line infection or sign of skin and soft tissue infection
ADD IV Vancomycin** Or, if true, penicillin/ beta-lactam allergy
IV Gentamicin**∆ (max 4 days) + IV Vancomycin**

NEWS ≥ 7 High Risk

IV Piperacillin/Tazobactam 4.5g 6 hourly + IV Gentamicin**∆ (max 4 days)
If MRSA colonised/ line infection or sign of skin and soft tissue infection
ADD IV Vancomycin**
Or if true penicillin/ beta-lactam allergy IV Gentamicin**∆ (max 4 days) + IV Vancomycin** + IV ▲■Ciprofloxacin 400mg 8 hourly

Patients with Stem Cell Transplants or receiving chemotherapy for Acute Leukaemia

NEWS ≤ 6 See High-Risk treatment above. NEWS ≥ 7 Critical Risk See Neutropenic Sepsis guidelines

Important Antibiotic Drug Interactions & Safety Information!!

▲Doxycycline/ Quinolone: reduced absorption with iron, calcium, magnesium & some nutritional supplements. See BNF (Appendix 1) or see the pharmacy for advice.
■ Clarithromycin/ Quinolone: risk of severe drug interactions. See BNF (Appendix 1) or see the pharmacy for advice. May also prolong the QTc interval and avoid (where possible) other QTc risk factors.
▲■ Quinolones:g., Ciprofloxacin, levofloxacin stop treatment at first signs of a serious adverse reaction (e.g., tendonitis), prescribe with caution for people over 60 years and avoid co-administration with a corticosteroid. See BNF for dosing advice in reduced renal function.

Gentamicin/ Vancomycin

Gentamicin/ Vancomycin adult dosing calculators are available via the ‘Clinical Info’ icon on the staff intranet / CCC App. Use Prescribing, Administration, and Monitoring charts
Vancomycin If creatinine is available, give Vancomycin loading dose as per actual body weight
Gentamicin Avoid Gentamicin in decompensated liver disease or myasthenia gravis

If creatinine is not available, give gentamicin as follows:
Actual Body Weight	Gentamicin Dose	Actual Body Weight	Gentamicin Dose
< 40 kg	5 mg/kg	60 – 69 kg	320 mg
40 – 49 kg	240 mg	70 – 79 kg	360 mg
50 – 59 kg	280 mg	>, = 80 kg	400 mg
NB if CKD5 give 2.5 mg/kg (max 180 mg)

FURTHER ADVICE:

Duty Microbiologist, Clinical/ Antimicrobial Pharmacist, Infectious Disease (ID) Unit at QEUH, local Respiratory Unit (for RTI) or from the Adult Therapeutic Handbook. The Duty Microbiologist may give Infection Control advice.

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