Adult

Cidofovir

General Information

Only to be prescribed following the recommendation of Micro/ID.

Restricted for use in the following indications. All other indications required MMTC Chair’s approval.

  1. Cytomegalovirus retinits in adults living with HIV
  2. Cytomegalovirus where ganciclovir is unsuitable due to resistance or contraindication
  3. Severe adenovirus infection
  4. Drug resistant herpes simplex infection
  5. Refractory varicella zoster infection
  6. Second-line treatment for BK hemorrhagic cystitis and BK nephropathy
  7. Mpox treatment

Cidofovir is manufactured by Baxter. Orders cannot be placed out of hours or over the weekend.

Dosage

Induction Treatment

Depending on the indication, Micro/ID may advise maintenance treatment. Dosing advice for maintenance treatment is not included in this monograph. Speak to Micro/ID for advice.

  IV
Standard Dose 

5mg/kg ONCE weekly

or

1mg/kg THREE times a week*

*1mg/kg three times a week is preferred in patients with renal impairment or those co-prescribed nephrotoxic drugs. Cost is significantly increased with use of this dose. Micro/ID may recommend on a case-by-case basis. Three times a week administration may not be possible in the event of a cidofovir stock shortage.

Obesity

Patients with a BMI greater than or equal to 30 kg/m2 should be dosed using adjusted body weight.

Adjusted Body Weight  = Ideal Body Weight + 0.4 x (Actual Body Weight– Ideal Body Weight)

 

Co-medications

Cidofovir must be co-prescribed with probenecid and fluids as per SPC. Prescribe using the Cidofovir Powerplan.

Fluid pre-load with 1L sodium chloride is recommended as per SPC, however, fluid administration can be tailored depending on individual patient factors e.g. heart failure, fluid overload.

See below for probenecid dosing information with cidofovir. Interactions, cautions and contraindications for probenecid may be found HERE.

Time Drug
Minus 3 hours
probenecid 2g po STAT
Minus 1 hour
1L 0.9% sodium chloride infused over 1 hour
Time 0
cidofovir intavenous infusion over 1 hour
Time 0 or + 1 hour (optional)
1L 0.9% sodium chloride over 1 - 3 hours 
+ 2 hours (after completion of cidofovir infusion)
probenecid 1g PO STAT 
+ 8 hours (after completion of cidofovir infusion) 
probenecid 1g PO STAT 

 

Renal and hepatic impairment

Renal Impairment 

Cidofovir is nephrotoxic in a dose-dependent manner and may cause renal impairment even after one dose. The renal dysfunction is not always reversible on withdrawal of the drug.

Cidofovir is contraindicated where creatinine clearance is less than or equal to 55ml/min, or proteinuria is greater than or equal to 100mg/dl.

Test urine for protein:

  • if negative, give normal dose.
  • if positive – proteinuria 2+ (1g/litre), reduce dose to 3mg/kg.
  • proteinuria 3+ or more (3g/litre), do not administer cidofovir

Consider using urine total protein:creatinine ratio to monitor renal function.

Cidofovir therapy should be discontinued and intravenous hydration is advised if serum creatinine increases by greater than or equal to 44 μmol/l, or if persistent proteinuria greater than or equal to 2+ develops. 

Cidofovir is contraindicated where creatinine clearance is less than or equal to 55ml/min but the following dose reductions may be considered following a risk assessment and discussion between the treating team and Micro/ID.

Creatinine clearance (ml/min) IV 
41 - 55 3mg/kg ONCE weekly*
30 - 40  2mg/kg ONCE weekly* 
Less than 30  Speak to Micro/ID and Pharmacy

Note: dose ranges use creatinine clearance, rather than eGFR.

*Consider renal sparing regimen (split doses e.g. 3 x week or 2 x week)

 

Hepatic Impairment 

Use with caution. 

Pregnancy and breastfeeding

Pregnancy

Do not use. Toxic in animal studies.

Breastfeeding

No information available. Discontinue breastfeeding if no alternative drug available. 

Additional information

Duration of treatment will depend on clinical course, viral titres, and degree of immunosuppression. Speak to Micro/ID.

Cidofovir is toxic and personnel should be adequately protected during handling and administration, if solution makes contact with skin or mucosa, wash off immediately with soap and water.

References

Editorial Information

Next review date: 02 Feb 2027