Canterbury DHB

Diarrhoea – Infection Associated

• See investigation and treatment guidelines for Acute Diarrhoea in Hospital HealthPathways.

Pathogens

• Common: Campylobacter jejuni, Salmonella species (non Typhi), Aeromonas species, Shigella species, and norovirus. C. difficile is particularly common in the elderly (see Diarrhoea – Clostridioides difficile).
• Other: Yersinia enterocolitica, Vibrio parahaemolyticus, Plesiomonas shigelloides, enterohaemorrhagic E. coli (0157:H7), amoebic dysentery

Drug Treatment

• Most do not require antimicrobial therapy.
• If elderly, immunocompromised, very severe illness, or bacteraemia, treat as below.
• If enterohaemorrhagic E. coli (0157:H7) infection (bloody stool and little or no fever) or haemolytic uraemic syndrome suspected, avoid antimicrobials and give supportive therapy.
• If pregnant, consult with Infectious Diseases/Clinical Microbiology.

Empiric

• Not recommended unless patient is immunocompromised or has severe symptoms.
• Recent travel (e.g. to South-east Asia) may increase likelihood of ciprofloxacin resistance (consider an alternative agent e.g. azithromycin).

If able to take oral therapy

ciprofloxacin HMLSchedNZFPMLnoids Ciprofloxacin F: 0.7 Half life: 4 hours Elimination: renal fe: 0.5 Additional points: Inhibits CYP1A2 and 3A. Antacids, milk, and enteral feeds ↓ absorption.

PO 500 mg twice a day for 5 days

• fe = 0.5, consider adjusting dose if CrCl reduced.
• Inhibits CYP1A2 (strong) and 3A.
• Subject to OAT and OATP (transporter) inhibition.
• Avoid in pregnancy and breastfeeding.

If unable to take oral therapy

ceftriaxone HMLSchedNZFPMLnoids Ceftriaxone F: n/a Half life: 8 hours Elimination: 50% renal and 50% biliary excretion fe: 0.5

IV 2 g every 24 hours then ciprofloxacin PO as above (5-day total course duration)

• fe = 0.5, consider adjusting dose if CrCl reduced.

Severe penicillin allergy and unable to take oral therapy

• fe = 0.5, consider adjusting dose if CrCl reduced.
• Inhibits CYP1A2 (strong) and 3A.
• Subject to OAT and OATP (transporter) inhibition.
• Avoid in pregnancy and breastfeeding.

Pathogens Known

Campylobacter jejuni

• Most patients do not require antimicrobial therapy.
• Antimicrobial therapy may be considered if illness is severe, or the patient is elderly or immunocompromised.

azithromycin HMLSchedNZFPML Azithromycin F: 0.4 Half life: 60 hours Elimination: substantial biliary excretion fe: 0.1 Additional points: ↑ warfarin effect.

500 mg once a day for 3 days

Salmonella species

• Consult Infectious Diseases/Clinical Microbiology.
• Only treat if patient is severely ill, septicaemic or immunocompromised.
• There is increasing Salmonella species resistance to both of the following antimicrobials, particularly if acquired overseas:

trimethoprim+sulfamethoxazole HMLSchedNZFPMLnoids Trimethoprim+Sulfamethoxazole F: 0.8 Half life: 9 hours / 12 hours Elimination: CYP2C8/9 acetylated fe: 0.3 / 0.7 (co-trimoxazole)

PO 160 mg/800 mg twice a day for 5 days

• fe (trimethoprim) = 0.7, fe (sulfamethoxazole) = 0.3, consider adjusting dose if CrCl reduced.
• Sulfamethoxazole is metabolised by CYP2C8/9 and conjugation.

OR

• fe = 0.5, consider adjusting dose if CrCl reduced.
• Inhibits CYP1A2 (strong) and 3A.
• Subject to OAT and OATP (transporter) inhibition.
• Avoid in pregnancy and breastfeeding.

If unable to tolerate oral treatment

Consult Infectious Diseases / Clinical Microbiology.

Shigella species

Treatment recommended for public health reasons.

• fe (trimethoprim) = 0.7, fe (sulfamethoxazole) = 0.3, consider adjusting dose if CrCl reduced.
• Sulfamethoxazole is metabolised by CYP2C8/9 and conjugation.

OR

• fe = 0.5, consider adjusting dose if CrCl reduced.
• Inhibits CYP1A2 (strong) and 3A.
• Subject to OAT and OATP (transporter) inhibition.
• Avoid in pregnancy and breastfeeding.

Other pathogens - Consult Infectious Diseases / Clinical Microbiology.

must be prescribed or recommended by a consultant.

Topic Code: 99235