Choose metabolic type:
Common brand name(s)
on drug exposure
Tegretol®, Equetro®, Carbatrol®
E-Mycin®, Eryc®, Ery-Tab®, PCE®, Ilosone®
Nizoral®, Extina®, Xolegel®, KuricTM
Numerous brand names available
This is a representative list of drugs and common brand names and is not intended to be exhaustive.
Dose=one tablet or one packet of oral granules.
aThese interactions have been studied.
bCo-administration with digoxin increased digoxin exposure by 1.3-fold.
cCo-administration with fluconazole increased KALYDECO exposure (AUC) by 3-fold.
dCo-administration with ketoconazole significantly increased KALYDECO exposure (AUC) by 8.5-fold.
eKALYDECO increased midazolam exposure by 1.5-fold.
fCo-administration with rifampin significantly decreased KALYDECO exposure (AUC) by approximately 9-fold.
AUC, area under the curve; INR, international normalized ratio.
Potential for other drugs to affect KALYDECO
Inhibitors of CYP3A
- Ivacaftor is a sensitive CYP3A substrate. Co-administration with ketoconazole, a strong CYP3A inhibitor, significantly increased ivacaftor exposure [measured as area under the curve (AUC)] by 8.5-fold. Based on simulations of these results, a reduction of the KALYDECO dose is recommended when co-administered with strong CYP3A inhibitors, such as ketoconazole, itraconazole, posaconazole, voriconazole, telithromycin, and clarithromycin, as follows: in patients 6 years and older reduce dose to one 150 mg tablet twice a week; in patients 2 to less than 6 years with body weight less than 14 kg, reduce dose to one 50 mg packet of granules twice a week; and in patients 2 to less than 6 years with body weight 14 kg or greater, reduce dose to one 75 mg packet of granules twice a week1
- Co-administration with fluconazole, a moderate inhibitor of CYP3A, increased ivacaftor exposure by 3-fold. Therefore, a reduction of the KALYDECO dose is recommended for patients taking concomitant moderate CYP3A inhibitors, such as fluconazole and erythromycin, as follows: in patients 6 years and older reduce dose to one 150 mg tablet once daily; in patients 2 to less than 6 years with body weight less than 14 kg, reduce dose to one 50 mg packet of granules once daily; and in patients 2 to less than 6 years with body weight 14 kg or greater, reduce dose to one 75 mg packet of granules once daily1
- Co-administration of KALYDECO with grapefruit juice, which contains one or more components that moderately inhibit CYP3A, may increase exposure of ivacaftor. Therefore, food containing grapefruit or Seville oranges should be avoided during treatment with KALYDECO1
Inducers of CYP3A
Co-administration with rifampin, a strong CYP3A inducer, significantly decreased ivacaftor exposure (AUC) by approximately 9-fold. Therefore, co-administration with strong CYP3A inducers, such as rifampin, rifabutin, phenobarbital, carbamazepine, phenytoin, and St. John’s wort is not recommended.1
Co-administration of KALYDECO with ciprofloxacin had no effect on the exposure of ivacaftor. Therefore, no dose adjustment is necessary during concomitant administration of KALYDECO with ciprofloxacin.1
Potential for KALYDECO to affect other drugs
CYP3A and/or P-gp substrates
Ivacaftor and its M1 metabolite have the potential to inhibit CYP3A and P-gp. Co-administration with midazolam, a sensitive CYP3A substrate, increased midazolam exposure 1.5-fold, consistent with weak inhibition of CYP3A by ivacaftor. Co-administration with digoxin, a sensitive P-gp substrate, increased digoxin exposure by 1.3-fold, consistent with weak inhibition of P-gp by ivacaftor. Administration of KALYDECO may increase systemic exposure of drugs that are substrates of CYP3A and/or P-gp, which may increase or prolong their therapeutic effect and adverse events. Therefore, caution and appropriate monitoring are recommended when co-administering KALYDECO with sensitive CYP3A and/or P-gp substrates, such as digoxin, cyclosporine, and tacrolimus.1