Pneumocytis jirovecii pneumonia (PCP) treatment

Solid organ transplant guidance
Royal Infirmary of Edinburgh

Initiating treatment:

  • Oral: if Pa02 > 10 kPa on room air
  • IV Otherwise:
  • Consider:
    • Steroids: if Sa02 <92% or PaO2 <9.3 kPa
    • Check G6PD status early on as second line therapy is often required

First line treatment: co-trimoxazole

  • Dose: 120mg/kg in 2-4 divided doses (round to nearest 480mg), reduce by 25% after 3 days
    • Duration: 3 weeks
    • IVOS: After a minimum 4 days of IV therapy, but beware of nausea
  • Renal dosing: Only if CrCl <30ml/min:
Creatinine Clearance First 72h Subsequently
15-30 ml/min 60mg/kg twice daily 30mg/kg twice daily
<15 ml/min 30mg/kg twice daily ~23mg/kg twice daily

NB: can be given centrally in concentrated form if fluid overload is a concern.

  • Monitoring: FBC, U&E – daily
  • Adverse Effects:
    • Common: nephrotoxicity, electrolyte abnormalities (esp. Renal SOT)
    • Less common: haematological abnormalities, neurological symptoms, headache, GI upset, skin reactions
    • If there are concerns about side effects, then consider switching to second line treatment
  • Monitoring co-trimoxazole levels is impractical due to turnaround times and has been found to be non contributory.

NB: It is important that the patient receives ~ 2 litres of 0.9% NaCl over 24 hrs, but with careful attention to fluid balance and potential overload.

Adjunctive Steroid Therapy

Steroids improve survival and shorten duration of illness in HIV patients with PCP, but clear evidence for this benefit is not available in non-HIV patients.

  • Indication: PaO2 <9.3 kPa (or SaO2 <92%) on room air, and still within 72h of antimicrobials being started
  • Dose: oral prednisolone
    • 40mg twice daily for 5 days, then
    • 40mg daily for 5 days, then
    • 20mg daily for 11 days then stop
  • Alternative: IV methylprednisolone (use 0.75x Prednisolone dose at all time points)

Second line treatment: clindamycin & primaquine

  • Doses:
    • IV clindamycin (600mg 3 times daily)
    • Oral primaquine (30mg once daily)
  • Monitoring: check G6PD status prior to starting
  • Adverse Effects: Nausea & vomiting, diarrhoea (inc. C difficile infection), abdominal pain, rash, methaemaglobinaemia and haemolytic anaemia (with primaquine in G6PD deficient patients)
    • Methaemoglobinaemia may present as increased SOB or an apparent worsening of the PCP. If this occurs check levels with haematology
    • If diarrhoea occurs test for C. difficile; start oral vancomycin empirically if high suspicion of infection (250mg 4 times daily)

Alternative second line treatment:

  • Discuss with microbiology/infectious diseases if alternative regimen is required.
  • Mild-moderate disease: oral atovaquone (750mg twice daily)
  • Severe disease: IV pentamidine (4mg/kg once daily)

Infection Control

  • There is evidence of spread amongst immunocompromised patients
  • Patients with PCP should be isolated in a single ensuite room (negative pressure if possible) in high risk patient areas
  • There is no need for health care worker RPE (i.e. masks)


Treatment recommendations are adapted for solid organ transplant unit from: Microguide, National IPCM, discussions with Infection specialists and local Transplant unit experience, and British HIV Association Opportunistic Infections Guidance


Version 1.0 2013; I Laurenson, K Helgason, S Watson and K Davidson.

V1.2 2014; Updated without Dr Helgason.

V1.3 August 2019; I Laurenson, L Henderson, D Dockrell, D O’Shea, P Phelan, C Hannah, P Lalonde, D Shaw, A Munro, C Hannah, J McCrae

Review date by August 2021