IN THIS SECTION: ALSO IN THIS SECTION:
View the Clinical Brochure

Drug Interactions with SYMDEKO®
(tezacaftor/ivacaftor and ivacaftor)

IN THIS SECTION: ALSO IN THIS SECTION:

Drug-Drug Interactions Tool

The Drug-Drug Interactions (DDI) tool provides the established or predicted effect of SYMDEKO on other medicinal products or effect of other medicinal products on SYMDEKO1-3

  • Clinical considerations are based on drug interaction studies, modeling, other clinical factors, and/or predicted interactions due to elimination pathways
  • Drugs shown within a therapeutic class do not represent all possible drugs within the class. Drugs within a class may have different metabolic profiles, and therefore, clinical recommendations apply only to the named drugs and not the class. The table does not represent all possible drugs or drug classes that a patient could be receiving. For further information, contact your clinical pharmacist

Choose or begin typing the brand or generic drug name or drug class to learn more about potential DDIs

Drug Class:

Drug Name Potential Effect Clinical Comment

Alprazolam
(Xanax®)2
  • No effect predicted
  • No dosage adjustments required

Warfarin
(Jantoven®)1
  • Warfarin exposure may be altered
  • Monitoring of the INR is recommended

INR, International Normalized Ratio

Aripiprazole
(Abilify®)2
  • No effect predicted
  • No dosage adjustments required

Atorvastatin
(Lipitor®)2
  • No effect predicted
  • No dosage adjustments required

Azithromycin
(Zithromax®)2
  • No effect predicted
  • No dosage adjustments required

Carbamazepine
(Carbatrol®, Epitol®, Equetro®, Tegretol®)1
  • Decreased SYMDEKO exposure
  • May reduce effectiveness of SYMDEKO, concomitant use not recommended

Ciprofloxacin*
(Cipro®)1
  • No effect predicted
  • No dosage adjustments required
    • Interaction with tezacaftor / ivacaftor has been studied. Exposure of ivacaftor increased with concomitant use, but effect was not clinically significant.

Citalopram
(Celexa®)2
  • No effect predicted
  • No dosage adjustments required

Clarithromycin
(Biaxin®)1
  • Increased SYMDEKO exposure

Clozapine
(Clozaril®, Versacloz®)2
  • No effect predicted
  • No dosage adjustments required

Cyclosporine
(Gengraf®, Neoral®, Sandimmune®)1
  • Cyclosporine
    exposure may increase
  • Drugs with a narrow therapeutic index should be used with caution and appropriate monitoring

Desipramine*
(Norpramin®)1
  • No effect predicted
  • No dosage adjustments required
    • Interaction with ivacaftor has been studied.

Dexamethasone2
  • No effect predicted
  • No dosage adjustments required

Diazepam
(Valium®)2
  • No effect predicted
  • No dosage adjustments required

Digoxin*
(Lanoxin®)1
  • Increased digoxin exposure
  • Drugs with a narrow therapeutic index should be used with caution and appropriate monitoring
    • Interaction with tezacaftor / ivacaftor has been studied. Co‑administration increased digoxin exposure by 1.3-fold.

Duloxetine
(Cymbalta®)2
  • No effect predicted
  • No dosage adjustments required

Erythromycin
(Ery-Tab®, Erythrocin®)1
  • Increased SYMDEKO exposure

Escitalopram
(Lexapro®)2
  • No effect predicted
  • No dosage adjustments required

Esomeprazole
(Nexium®)2
  • No effect predicted
  • No dosage adjustments required

Ethinyl estradiol/Norethindrone, other oral contraceptives
(Afirmelle®,
Altavera®,
Aviane®,
Ayuna®,
Enpresse®,
Falmina®,
Kurvelo®,
Lessina®,
Levora®,
Loestrin®,
Marlissa®,
Myzilra®,
Nordette®,
Portia-28®,
Trivora-28®,
Vienva®)1,2
  • No effect predicted
  • SYMDEKO not expected to modify efficacy
    of hormonal contraceptives

Everolimus
(Afinitor®, Zortress®)1
  • Everolimus exposure may increase
  • Drugs with a narrow therapeutic index should be used with caution and appropriate monitoring

Fluconazole*
(Diflucan®)1
  • Increased SYMDEKO exposure
  • SYMDEKO dosing regimen should be adjusted. For full dosing table, click here
    • Interaction with ivacaftor has been studied. Co‑administration with fluconazole increased ivacaftor exposure by 3.0-fold; simulation suggests tezacaftor exposure may increase by approximately 2.0-fold.

Fluoxetine
(Prozac®)2
  • No effect predicted
  • No dosage adjustments required

Fluvastatin
(Lescol®)2
  • No effect predicted
  • No dosage adjustments required

Glimepiride
(Amaryl®)1
  • Increased exposure of glimepiride may occur
  • Use caution and appropriate monitoring

Glipizide
(Glucotrol®)1
  • Increased exposure of glipizide may occur
  • Use caution and appropriate monitoring

Ibuprofen
(Advil®, Motrin IB®)2
  • No effect predicted
  • No dosage adjustments required

Itraconazole*
(Sporanox®)1
  • Increased SYMDEKO exposure
  • SYMDEKO dosing regimen should be adjusted. For full dosing table, click here
    • Interaction with tezacaftor / ivacaftor has been studied. Co‑administration with itraconazole increased tezacaftor exposure by 4.0-fold and ivacaftor exposure by 15.6-fold.

Ketoconazole
(Nizoral®)1
  • Increased SYMDEKO exposure

Lansoprazole
(Prevacid®)2
  • No effect predicted
  • No dosage adjustments required

Lovastatin2
  • No effect predicted
  • No dosage adjustments required

Metformin
(Glumetza®, Riomet®)2
  • No effect predicted
  • No dosage adjustments required

Methylprednisolone
(Medrol®)2
  • No effect predicted
  • No dosage adjustments required

Midazolam (oral)1*
  • No effect predicted
  • No dosage adjustments required
    • Interaction with tezacaftor / ivacaftor has been studied.

Mirtazapine
(Remeron®)2
  • No effect predicted
  • No dosage adjustments required

Montelukast
(Singulair®)2
  • No effect predicted
  • No dosage adjustments required

Nateglinide2
  • No effect predicted
  • No dosage adjustments required

Omeprazole
(Prilosec®)2
  • No effect predicted
  • No dosage adjustments required

Paroxetine
(Brisdelle®, Paxil®, Pexeva®)2
  • No effect predicted
  • No dosage adjustments required

Phenobarbital1
  • Decreased SYMDEKO exposure
  • May reduce effectiveness of SYMDEKO, concomitant use not recommended

Phenytoin
(Dilantin®, Phenytek®)1
  • Decreased SYMDEKO exposure
  • May reduce effectiveness of SYMDEKO, concomitant use not recommended

Pitavastatin
(Livalo®, Zypitamag®)1
  • Effect is not clinically significant
  • No dosage adjustments required

Posaconazole
(Noxafil®)1
  • Increased SYMDEKO exposure

Pravastatin2
  • No effect predicted
  • No dosage adjustments required

Prednisolone2
  • No effect predicted
  • No dosage adjustments required

Prednisone2
  • No effect predicted
  • No dosage adjustments required

Quetiapine
(Seroquel®)2
  • No effect predicted
  • No dosage adjustments required

Ranitidine
(Zantac®)2
  • No effect predicted
  • No dosage adjustments required

Repaglinide2
  • No effect predicted
  • No dosage adjustments required

Rifabutin
(Mycobutin®)1
  • Decreased SYMDEKO exposure
  • May reduce effectiveness of SYMDEKO, concomitant use not recommended

Rifampin*
(Rifadin®)1
  • Decreased SYMDEKO exposure
  • May reduce effectiveness of SYMDEKO, concomitant use not recommended
    • Interaction with ivacaftor has been studied. Co‑administration of ivacaftor with rifampin significantly decreased ivacaftor exposure by 89%.

Risperidone
(Perseris®, Risperdal®)2
  • No effect predicted
  • No dosage adjustments required

Rosiglitazone*
(Avandia®)1
  • No effect predicted
  • No dosage adjustments required
    • Interaction with ivacaftor has been studied.

Rosuvastatin
(Crestor®, Ezallor®)2
  • No effect predicted
  • No dosage adjustments required

Sertraline
(Zoloft®)2
  • No effect predicted
  • No dosage adjustments required

Simvastatin
(Zocor®, Flolipid®)2
  • No effect predicted
  • No dosage adjustments required

Sirolimus
(Rapamune®)1
  • Sirolimus exposure may increase
  • Drugs with a narrow therapeutic index should be used with caution and appropriate monitoring

St. John’s wort
(Hypericum perforatum)1
  • Decreased SYMDEKO exposure
  • May reduce effectiveness of SYMDEKO, concomitant use not recommended

Tacrolimus
(Prograf®)1
  • Tacrolimus exposure may increase
  • Drugs with a narrow therapeutic index should be used with caution and appropriate monitoring

Telithromycin1
  • Increased SYMDEKO exposure

Trazodone2
  • No effect predicted
  • No dosage adjustments required

Triazolam
(Halcion®)2
  • No effect predicted
  • No dosage adjustments required

Voriconazole
(Vfend®)1
  • Increased SYMDEKO exposure

Warfarin
(Jantoven®)1
  • Warfarin exposure may be altered
  • Monitoring of the INR is recommended

INR, International Normalized Ratio

Drug names in the table that are bold are listed in the full Prescribing Information for SYMDEKO.

Potential drug interactions with SYMDEKO

STRONG CYP3A Inducers1

Examples

Effect

Clinical Recommendation

  • Rifampinᵃ
  • Rifabutin
  • Phenobarbital
  • Carbamazepine
  • Phenytoin
  • St. John’s wort (Hypericum perforatum)
  • Reduced blood levels of SYMDEKO are expected, potentially resulting in reduced efficacy
  • Concomitant use is not recommended

STRONG CYP3A Inhibitors1

Examples

Effect

Clinical Recommendation

  • Ketoconazole
  • Itraconazoleᵇ
  • Posaconazole
  • Voriconazole
  • Telithromycin
  • Clarithromycin
  • Increased blood levels of SYMDEKO are expected
  • SYMDEKO dosing adjustment is recommended


For full dosing table, click here.

MODERATE CYP3A Inhibitors1

Examples

Effect

Clinical Recommendation

  • Fluconazolec
  • Erythromycin
  • Increased blood levels of SYMDEKO are expected
  • SYMDEKO dosing adjustment is recommended


For full dosing table, click here.

Food/Drink1

  • Grapefruit
  • Increased blood levels of SYMDEKO are expected
  • Avoid during treatment with SYMDEKO

For full dosing table, click here.

CYP2C9 Substrate1,2

Examples

Effect

Clinical Recommendation

  • Warfarin
  • Ivacaftor may inhibit CYP2C9 and increase exposures of these drugs
  • Monitor international normalized ratio
  • Glimepiride
  • Glipizide
     
  • Ivacaftor may inhibit CYP2C9 and increase exposures of these drugs
     
  • Use with caution

P-gp Substrates1,2

Examples

Effect

Clinical Recommendation

  • Digoxin
  • Cyclosporine
  • Everolimus
  • Sirolimus
  • Tacrolimus
  • SYMDEKO increased digoxin exposure and may increase exposure of other sensitive P-gp substrates
  • Caution and appropriate monitoring of these drugs should be used

STRONG CYP3A Inducers1

Examples

  • Rifampinᵃ
  • Rifabutin
  • Phenobarbital
  • Carbamazepine
  • Phenytoin
  • St. John’s wort (Hypericum perforatum)

Effect

  • Reduced blood levels of SYMDEKO are expected, potentially resulting in reduced efficacy

Clinical Recommendation

  • Concomitant use is not recommended

STRONG CYP3A Inhibitors1

Examples

  • Ketoconazole
  • Itraconazoleᵇ
  • Posaconazole
  • Voriconazole
  • Telithromycin
  • Clarithromycin

Effect

  • Increased blood levels of SYMDEKO are expected

Clinical Recommendation

  • SYMDEKO dosing adjustment is recommended


For full dosing table, click here.

MODERATE CYP3A Inhibitors1

Examples

  • Fluconazolec
  • Erythromycin

Effect

  • Increased blood levels of SYMDEKO are expected

Clinical Recommendation

  • SYMDEKO dosing adjustment is recommended


For full dosing table, click here.

Examples

Food/Drink1

  • Grapefruit

Effect

  • Increased blood levels of SYMDEKO are expected

Clinical Recommendation

  • Avoid during treatment with SYMDEKO

For full dosing table, click here.

CYP2C9 Substrate1,2

Examples

  • Warfarin

Effect

  • Ivacaftor may inhibit CYP2C9 and increase exposures of these drugs

Clinical Recommendation

  • Monitor international normalized ratio

Examples

  • Glimepiride
  • Glipizide
     

Effect

  • Ivacaftor may inhibit CYP2C9 and increase exposures of these drugs
     

Clinical Recommendation

  • Use with caution

P-gp Substrates1,2

Examples

  • Digoxin
  • Cyclosporine
  • Everolimus
  • Sirolimus
  • Tacrolimus

Effect

  • SYMDEKO increased digoxin exposure and may increase exposure of other sensitive P-gp substrates

Clinical Recommendation

  • Caution and appropriate monitoring of these drugs should be used

aCo-administration of ivacaftor with rifampin, a strong CYP3A inducer, significantly decreased ivacaftor exposure (AUC) by 89%; tezacaftor exposures can also be expected to decrease significantly.1
bCo-administration with itraconazole, a strong CYP3A inhibitor, increased tezacaftor exposure (AUC) by 4.0-fold and ivacaftor by 15.6-fold.1
cCo-administration with fluconazole, a moderate CYP3A inhibitor, increased ivacaftor exposure (AUC) by approximately 3.0-fold, and may increase tezacaftor exposure by approximately 2.0-fold.1

Drugs not expected to have a clinically significant effect on SYMDEKO or vice versa

Drugs not requiring dose adjustments1,2

Examples (The list below is not intended to be exhaustive)

  • Oral contraceptives (ethinyl estradiol/norethindrone)
  • Specific antidepressants (desipramine, citalopram, escitalopram, sertraline, mirtazapine, paroxetine, trazodone)
  • Azithromycin
  • CYP3A substrates (e.g., midazolam [oral])
  • Ciprofloxacin
  • Pitavastatin (an OATP1B1 substrate)

AUC, area under the curve.

Explore Downloadable
Resources

INDICATIONS AND USAGE

SYMDEKO is indicated for the treatment of cystic fibrosis (CF) in patients age 6 years and older who are homozygous for the F508del mutation or who have at least one mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene that is responsive to tezacaftor/ivacaftor based on in vitro data and/or clinical evidence.

If the patient’s genotype is unknown, an FDA-cleared CF mutation test should be used to detect the presence of a CFTR mutation followed by verification with bi-directional sequencing when recommended by the mutation test instructions for use.

INDICATIONS AND USAGE

SYMDEKO is indicated for the treatment of cystic fibrosis (CF) in patients age 6 years and older who are homozygous for the F508del mutation or who have at least one mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene that is responsive to tezacaftor/ivacaftor based on in vitro data and/or clinical evidence.

If the patient’s genotype is unknown, an FDA-cleared CF mutation test should be used to detect the presence of a CFTR mutation followed by verification with bi-directional sequencing when recommended by the mutation test instructions for use.

IMPORTANT SAFETY INFORMATION

WARNINGS AND PRECAUTIONS

Transaminase (ALT or AST) Elevations

  • Elevated transaminases have been observed in patients with CF receiving SYMDEKO, as well as with ivacaftor monotherapy. Assessments of transaminases (ALT and AST) are recommended prior to initiating SYMDEKO, every 3 months during the first year of treatment, and annually thereafter. For patients with a history of transaminase elevations, more frequent monitoring should be considered
  • Dosing should be interrupted in patients with significant elevations of transaminases (e.g., ALT or AST >5x upper limit of normal [ULN], or ALT or AST >3x ULN with bilirubin >2x ULN) and laboratory tests should be closely followed until abnormalities resolve. Following resolution of transaminase elevations, consider the benefits and risks of resuming treatment

Hypersensitivity Reactions, Including Anaphylaxis

  • Hypersensitivity reactions, including cases of anaphylaxis, have been reported in the postmarketing setting. If signs or symptoms of serious hypersensitivity reactions develop during treatment, discontinue SYMDEKO and institute appropriate therapy. Consider the benefits and risks for the individual patient to determine whether to resume treatment with SYMDEKO

Concomitant Use With CYP3A Inducers

  • Exposure to ivacaftor is significantly decreased and exposure to tezacaftor may be reduced by concomitant use of CYP3A inducers, which may reduce the therapeutic effectiveness of SYMDEKO. Co-administration of SYMDEKO with strong CYP3A inducers, such as rifampin, rifabutin, phenobarbital, carbamazepine, phenytoin, and St. John’s wort, is not recommended

Cataracts

  • Cases of non-congenital lens opacities have been reported in pediatric patients treated with SYMDEKO, as well as with ivacaftor monotherapy. Baseline and follow-up ophthalmological examinations are recommended in pediatric patients initiating treatment with SYMDEKO

ADVERSE REACTIONS

Serious Adverse Reactions

  • Serious adverse reactions, whether considered drug-related or not by the investigators, that occurred more frequently in patients treated with SYMDEKO compared to placebo included distal intestinal obstruction syndrome, 3 (0.6%) patients treated with SYMDEKO vs. 0 placebo patients

Most Common Adverse Reactions

  • The most common adverse reactions in Trials 1 and 3 occurring in ≥3% of patients treated with SYMDEKO (N=334) and at a higher rate than for placebo (N=343) were headache, nausea, sinus congestion, and dizziness
  • The safety profile in patients age 6 to less than 12 years from an open-label Phase 3 trial (N=70) was similar to that observed in Trials 1 and 3

USE IN SPECIFIC POPULATION

Pediatric Use

  • The safety and effectiveness of SYMDEKO in patients with CF younger than 6 years of age have not been studied

Click here to access full Prescribing Information.

References:
1. SYMDEKO [prescribing information]. Boston, MA: Vertex Pharmaceuticals Incorporated; August 2023. 2. Data on file. Vertex Pharmaceuticals Incorporated. Boston, MA. REF-10745 (v2.0); 2021. 3. FDA U.S. Food & Drug Administration. Drugs@FDA: FDA-Approved Drugs. https://www.accessdata.fda.gov/scripts/cder/daf/. Accessed March 1, 2023. 

 

 

INDICATIONS AND USAGE

SYMDEKO is indicated for the treatment of cystic fibrosis (CF) in patients age 6 years and older who are homozygous for the F508del mutation or who have at least one mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene that is responsive to tezacaftor/ivacaftor based on in vitro data and/or clinical evidence.

If the patient’s genotype is unknown, an FDA-cleared CF mutation test should be used to detect the presence of a CFTR mutation followed by verification with bi-directional sequencing when recommended by the mutation test instructions for use.

IMPORTANT SAFETY INFORMATION

WARNINGS AND PRECAUTIONS

Transaminase (ALT or AST) Elevations

  • Elevated transaminases have been observed in patients with CF receiving SYMDEKO, as well as with ivacaftor monotherapy. Assessments of transaminases (ALT and AST) are recommended prior to initiating SYMDEKO, every 3 months during the first year of treatment, and annually thereafter. For patients with a history of transaminase elevations, more frequent monitoring should be considered
  • Dosing should be interrupted in patients with significant elevations of transaminases (e.g., ALT or AST >5x upper limit of normal [ULN], or ALT or AST >3x ULN with bilirubin >2x ULN) and laboratory tests should be closely followed until abnormalities resolve. Following resolution of transaminase elevations, consider the benefits and risks of resuming treatment

Hypersensitivity Reactions, Including Anaphylaxis

  • Hypersensitivity reactions, including cases of anaphylaxis, have been reported in the postmarketing setting. If signs or symptoms of serious hypersensitivity reactions develop during treatment, discontinue SYMDEKO and institute appropriate therapy. Consider the benefits and risks for the individual patient to determine whether to resume treatment with SYMDEKO

Concomitant Use With CYP3A Inducers

  • Exposure to ivacaftor is significantly decreased and exposure to tezacaftor may be reduced by concomitant use of CYP3A inducers, which may reduce the therapeutic effectiveness of SYMDEKO. Co-administration of SYMDEKO with strong CYP3A inducers, such as rifampin, rifabutin, phenobarbital, carbamazepine, phenytoin, and St. John’s wort, is not recommended

Cataracts

  • Cases of non-congenital lens opacities have been reported in pediatric patients treated with SYMDEKO, as well as with ivacaftor monotherapy. Baseline and follow-up ophthalmological examinations are recommended in pediatric patients initiating treatment with SYMDEKO

ADVERSE REACTIONS

Serious Adverse Reactions

  • Serious adverse reactions, whether considered drug-related or not by the investigators, that occurred more frequently in patients treated with SYMDEKO compared to placebo included distal intestinal obstruction syndrome, 3 (0.6%) patients treated with SYMDEKO vs. 0 placebo patients

Most Common Adverse Reactions

  • The most common adverse reactions in Trials 1 and 3 occurring in ≥3% of patients treated with SYMDEKO (N=334) and at a higher rate than for placebo (N=343) were headache, nausea, sinus congestion, and dizziness
  • The safety profile in patients age 6 to less than 12 years from an open-label Phase 3 trial (N=70) was similar to that observed in Trials 1 and 3

USE IN SPECIFIC POPULATIONS

Pediatric Use

  • The safety and effectiveness of SYMDEKO in patients with CF younger than 6 years of age have not been studied

Click here to access full Prescribing Information.

References:
1. SYMDEKO [prescribing information]. Boston, MA: Vertex Pharmaceuticals Incorporated; August 2023. 2. Data on file. Vertex Pharmaceuticals Incorporated. Boston, MA. REF-10745 (v2.0); 2021. 3. FDA U.S. Food & Drug Administration. Drugs@FDA: FDA-Approved Drugs. https://www.accessdata.fda.gov/scripts/cder/daf/. Accessed March 1, 2023.