DOSE IN RENAL IMPAIRMENT

GFR (mL/MIN)

DOSE IN PATIENTS UNDERGOING RENAL REPLACEMENT THERAPIES

IMPORTANT DRUG INTERACTIONS

Potentially hazardous interactions with other drugsCiclosporin and tacrolimus: interferon reported to reduce the activity of hepatic cytochrome P450 enzymes

ADMINISTRATION

Reconstition

With diluent provided

Route

IM (Avonex), SC (Rebif, Betaferon)

Rate of Administration

–

Comments

Stable for 6 hours at 2–8 oC once reconstituted

OTHER INFORMATION

Pre-treatment with paracetamol is recommended to reduce incidence of flu-like symptomsVary the site of injection each week Rare cases of lupus erythematosus syndrome have occurredTransient increases in creatinine, potassium, urea, nitrogen and urinary calcium may occurInterferon up-regulates the cell surface presentation of class II histocompatibility antigens, which raises the possibility of drug-induced allograft rejection. There are numerous clinical reports of allograft rejection, acute renal failure and graft loss after interferon therapy. Hence extreme care should be exercised in the use of interferon after renal transplantationInterferon is metabolised primarily in the kidney. It is excreted in the urine, but is reabsorbed by the tubules where it undergoes lysosomal degradation. In patients undergoing haemodialysis, the interferon molecule may accumulate as it is too large to be dialysed and will not undergo renal degradation. Hence, the dose may need to be adjusted.