| Medicinal product [Mechanism of Interaction] | Interaction Geometric mean changes (%) | Recommendations concerning co-administration |
| Astemizole, cisapride, pimozide, quinidine and terfenadine
[CYP3A4 substrates] | Although not studied, increased plasma concentrations of these medicinal products can lead to QTc prolongation and rare occurrences of torsades de pointes.
| Contraindicated (see section 4.3)
|
| Carbamazepine and long-acting barbiturates (e.g., phenobarbital, mephobarbital) [potent CYP450 inducers] | Although not studied, carbamazepine and long-acting barbiturates are likely to significantly decrease plasma voriconazole concentrations.
| Contraindicated (see section 4.3)
|
Efavirenz (a non-nucleoside reverse transcriptase inhibitor) [CYP450 inducer; CYP3A4 inhibitor and substrate]High dose (400 mg QD)*
Low dose (300 mg QD, co-administered with voriconazole 400 mg BID)* |
Efavirenz Cmax ↑ 38% Efavirenz AUC ↑ 44%
Voriconazole Cmax 61% Voriconazole AUC 77%
Compared to efavirenz 600 mg QD,
Efavirenz Cmax ↔ Efavirenz AUC ↑ 17%
Compared to voriconazole 200 mg BID,
Voriconazole Cmax ↑ 23% Voriconazole AUC 7%
|
Standard doses of voriconazole and standard doses of efavirenz (400 mg QD or above) is contraindicated (see section 4.3).
Voriconazole may be co-administered with efavirenz if the voriconazole maintenance dose is increased to 400 mg BID and the efavirenz dose is decreased to 300 mg QD. When voriconazole treatment is stopped, the initial dose of efavirenz should be restored (see section 4.2).
|
| Ergot alkaloids (e.g., ergotamine and dihydroergotamine)[CYP3A4 substrates] | Although not studied, voriconazole is likely to increase the plasma concentrations of ergot alkaloids and lead to ergotism.
| Contraindicated (see section 4.3)
|
Rifabutin
[potent CYP450 inducer]300 mg QD
300 mg QD (co-administered with voriconazole 350 mg BID)*
300 mg QD (co-administered with voriconazole 400 mg BID)* | Voriconazole Cmax 69% Voriconazole AUC 78%
Compared to voriconazole 200 mg BID,
Voriconazole Cmax 4% Voriconazole AUC 32%
Rifabutin Cmax ↑ 195% Rifabutin AUC ↑ 331%
Compared to voriconazole 200 mg BID,
Voriconazole Cmax ↑ 104% Voriconazole AUC ↑ 87%
| Concomitant use of voriconazole and rifabutin should be avoided unless the benefit outweighs the risk.
The maintenance dose of voriconazole may be increased to 5 mg/kg intravenously BID or from 200 mg to 350 mg orally BID (100 mg to 200 mg orally BID in patients less than 40 kg) (see section 4.2).
Careful monitoring of full blood counts and adverse reactions to rifabutin (e.g., uveitis) is recommended when rifabutin is coadministered with voriconazole.
|
| Rifampicin (600 mg QD)[potent CYP450 inducer] | Voriconazole Cmax 93% Voriconazole AUC 96%
| Contraindicated (see section 4.3)
|
Ritonavir (protease inhibitor) [potent CYP450 inducer; CYP3A4 inhibitor and substrate]High dose (400 mg BID)
Low dose (100 mg BID)* |
Ritonavir Cmax and AUC ↔ Voriconazole Cmax 66% Voriconazole AUC 82% Ritonavir Cmax 25% Ritonavir AUC 13% Voriconazole Cmax 24% Voriconazole AUC 39%
|
Co-administration of voriconazole and high doses of ritonavir (400 mg and above BID) is contraindicated (see section 4.3).
Co-administration of voriconazole and low dose ritonavir (100 mg BID) should be avoided, unless an assessment of the benefit/risk to the patient justifies the use of voriconazole.
|
| St John's Wort
[CYP450 inducer; P-gp inducer]300 mg TID (co-administered with voriconazole 400 mg single dose)
| In an independent published study,
Voriconazole AUC0- 59%
| Contraindicated (see section 4.3)
|
| Everolimus
[CYP3A4 substrate, P-gP substrate] | Although not studied, voriconazole is likely to significantly increase the plasma concentrations of everolimus.
| Co-administration of voriconazole with everolimus is not recommended because voriconazole is expected to significantly increase everolimus concentrations (see section 4.4).
|
| Fluconazole (200 mg QD)[CYP2C9, CYP2C19 and CYP3A4 inhibitor] | Voriconazole Cmax ↑ 57% Voriconazole AUC ↑ 79%
Fluconazole Cmax ND Fluconazole AUC ND
| The reduced dose and/or frequency of voriconazole and fluconazole that would eliminate this effect have not been established. Monitoring for voriconazole-associated adverse reactions is recommended if voriconazole is used sequentially after fluconazole.
|
Phenytoin [CYP2C9 substrate and potent CYP450 inducer]300 mg QD
300 mg QD (co-administered with voriconazole 400 mg BID)* |
Voriconazole Cmax 49% Voriconazole AUC 69%
Phenytoin Cmax ↑ 67% Phenytoin AUC ↑ 81%
Compared to voriconazole 200 mg BID,
Voriconazole Cmax ↑ 34% Voriconazole AUC ↑ 39%
| Concomitant use of voriconazole and phenytoin should be avoided unless the benefit outweighs the risk. Careful monitoring of phenytoin plasma levels is recommended.
Phenytoin may be co-administered with voriconazole if the maintenance dose of voriconazole is increased to 5 mg/kg IV BID or from 200 mg to 400 mg oral BID, (100 mg to 200 mg oral BID in patients less than 40 kg) (see section 4.2).
|
| Anticoagulants
Warfarin (30 mg single dose, co- administered with 300 mg BID voriconazole)
[CYP2C9 substrate]Other oral coumarins (e.g., phenprocoumon, acenocoumarol)
[CYP2C9 and CYP3A4 substrates] | Maximum increase in prothrombin time was approximately 2-fold
Although not studied, voriconazole may increase the plasma concentrations of coumarins that may cause an increase in prothrombin time.
| Close monitoring of prothrombin time or other suitable anticoagulation tests is recommended, and the dose of anticoagulants should be adjusted accordingly.
|
| Benzodiazepines (e.g., midazolam, triazolam, alprazolam)
[CYP3A4 substrates] | Although not studied clinically, voriconazole is likely to increase the plasma concentrations of benzodiazepines that are metabolised by CYP3A4 and lead to a prolonged sedative effect.
| Dose reduction of benzodiazepines should be considered.
|
Immunosuppressants[CYP3A4 substrates] Sirolimus (2 mg single dose)
Ciclosporin (In stable renal transplant recipients receiving chronic ciclosporin therapy)
Tacrolimus (0.1 mg/kg single dose) | In an independent published study, Sirolimus Cmax ↑ 6.6-fold Sirolimus AUC0- ↑ 11-fold
Ciclosporin Cmax ↑ 13% Ciclosporin AUC ↑ 70%
Tacrolimus Cmax ↑ 117% Tacrolimus AUCt ↑ 221%
| Co-administration of voriconazole and sirolimus is contraindicated (see section 4.3).
When initiating voriconazole in patients already on ciclosporin it is recommended that the ciclosporin dose be halved and ciclosporin level carefully monitored. Increased ciclosporin levels have been associated with nephrotoxicity. When voriconazole is discontinued, ciclosporin levels must be carefully monitored and the dose increased as necessary.
When initiating voriconazole in patients already on tacrolimus, it is recommended that the tacrolimus dose be reduced to a third of the original dose and tacrolimus level carefully monitored. Increased tacrolimus levels have been associated with nephrotoxicity. When voriconazole is discontinued, tacrolimus levels must be carefully monitored and the dose increased as necessary.
|
| Long Acting Opiates
[CYP3A4 substrates]Oxycodone (10 mg single dose)
| In an independent published study,
Oxycodone Cmax↑ 1.7-fold Oxycodone AUC0- ↑ 3.6-fold
| Dose reduction in oxycodone and other long-acting opiates metabolized by CYP3A4 (e.g., hydrocodone) should be considered. Frequent monitoring for opiate-associated adverse reactions may be necessary.
|
| Methadone (32-100 mg QD)
[CYP3A4 substrate] | R-methadone (active) Cmax ↑ 31% R-methadone (active) AUC ↑ 47% S-methadone Cmax ↑ 65% S-methadone AUC ↑ 103%
| Frequent monitoring for adverse reactions and toxicity related to methadone, including QT prolongation, is recommended. Dose reduction of methadone may be needed.
|
Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) [CYP2C9 substrates]Ibuprofen (400 mg single dose)
Diclofenac (50 mg single dose)
|
S-Ibuprofen Cmax ↑ 20% S-Ibuprofen AUC0- ↑ 100%
Diclofenac Cmax ↑ 114% Diclofenac AUC0- ↑ 78%
|
Frequent monitoring for adverse reactions and toxicity related to NSAIDs is recommended. Dose reduction of NSAIDs may be needed.
|
| Omeprazole (40 mg QD)*[CYP2C19 inhibitor; CYP2C19 and CYP3A4 substrate] | Omeprazole Cmax↑ 116% Omeprazole AUC ↑ 280%
Voriconazole Cmax ↑ 15% Voriconazole AUC ↑ 41%
Other proton pump inhibitors that are CYP2C19 substrates may also be inhibited by voriconazole and may result in increased plasma concentrations of these medicinal products.
| No dose adjustment of voriconazole is recommended.
When initiating voriconazole in patients already receiving omeprazole doses of 40 mg or above, it is recommended that the omeprazole dose be halved.
|
| Oral Contraceptives*[CYP3A4 substrate; CYP2C19 inhibitor]Norethisterone/ethinylestradiol (1 mg/0.035 mg QD)
| Ethinylestradiol Cmax ↑ 36% Ethinylestradiol AUC ↑ 61%
Norethisterone Cmax ↑ 15% Norethisterone AUC ↑ 53%
Voriconazole Cmax ↑ 14% Voriconazole AUC ↑ 46%
| Monitoring for adverse reactions related to oral contraceptives, in addition to those for voriconazole, is recommended.
|
Short Acting Opiates
[CYP3A4 substrates] Alfentanil (20 μg/kg single dose, with concomitant naloxone)
Fentanyl (5 μg/kg single dose)
| In an independent published study,
Alfentanil AUC0- ↑ 6-fold
In an independent published study,
Fentanyl AUC0- ↑ 1.34-fold
| Dose reduction of alfentanil, fentanyl and other short acting opiates similar in structure to alfentanil and metabolised by CYP3A4 (e.g., sufentanil) should be considered. Extended and frequent monitoring for respiratory depression and other opiate-associated adverse reactions is recommended.
|
| Statins (e.g., lovastatin)[CYP3A4 substrates] | Although not studied clinically, voriconazole is likely to increase the plasma concentrations of statins that are metabolised by CYP3A4 and could lead to rhabdomyolysis.
| Dose reduction of statins should be considered.
|
| Sulphonylureas (e.g., tolbutamide, glipizide, glyburide)
[CYP2C9 substrates] | Although not studied, voriconazole is likely to increase the plasma concentrations of sulphonylureas and cause hypoglycaemia.
| Careful monitoring of blood glucose is recommended. Dose reduction of sulfonylureas should be considered.
|
| Vinca Alkaloids (e.g., vincristine and vinblastine)[CYP3A4 substrates] | Although not studied, voriconazole is likely to increase the plasma concentrations of vinca alkaloids and lead to neurotoxicity.
| Dose reduction of vinca alkaloids should be considered.
|
| Other HIV Protease Inhibitors (e.g., saquinavir, amprenavir and nelfinavir)*[CYP3A4 substrates and inhibitors] | Not studied clinically. In vitro
studies show that voriconazole may inhibit the metabolism of HIV protease inhibitors and the metabolism of voriconazole may also be inhibited by HIV protease inhibitors.
| Careful monitoring for any occurrence of drug toxicity and/or lack of efficacy, and dose adjustment may be needed.
|
| Other Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTIs) (e.g., delavirdine, nevirapine)*[CYP3A4 substrates, inhibitors or CYP450 inducers] | Not studied clinically. In vitro
studies show that the metabolism of voriconazole may be inhibited by NNRTIs and voriconazole may inhibit the metabolism of NNRTIs.
The findings of the effect of efavirenz on voriconazole suggest that the metabolism of voriconazole may be induced by a NNRTI.
| Careful monitoring for any occurrence of drug toxicity and/or lack of efficacy, and dose adjustment may be needed.
|
| Cimetidine (400 mg BID)[non-specific CYP450 inhibitor and increases gastric pH] | Voriconazole Cmax ↑ 18% Voriconazole AUC ↑ 23%
| No dose adjustment
|
| Digoxin (0.25 mg QD)[P-gp substrate] | Digoxin Cmax ↔ Digoxin AUC ↔ | No dose adjustment
|
| Indinavir (800 mg TID)[CYP3A4 inhibitor and substrate] | Indinavir Cmax ↔ Indinavir AUC ↔Voriconazole Cmax ↔ Voriconazole AUC ↔ | No dose adjustment
|
| Macrolide antibiotics
Erythromycin (1 g BID)[CYP3A4 inhibitor] Azithromycin (500 mg QD)
| Voriconazole Cmax and AUC ↔
Voriconazole Cmax and AUC ↔The effect of voriconazole on either erythromycin or azithromycin is unknown.
| No dose adjustment
|
| Mycophenolic acid (1 g single dose)
[UDP-glucuronyl transferase substrate] | Mycophenolic acid Cmax ↔ Mycophenolic acid AUCt ↔ | No dose adjustment
|
| Prednisolone (60 mg single dose) [CYP3A4 substrate] | Prednisolone Cmax ↑ 11% Prednisolone AUC0- ↑ 34%
| No dose adjustment
|
| Ranitidine (150 mg BID)[increases gastric pH] | Voriconazole Cmax and AUC ↔ | No dose adjustment
|