Lansoprazole and Voriconazole: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Voriconazole
Lansoprazole
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
Increased lansoprazole exposure
Interaction Deep Dive
Lansoprazole is metabolized by CYP2C19 and CYP3A4. Concomitant administration with voriconazole, a strong inhibitor of CYP2C19 and CYP3A4, may cause increased lansoprazole plasma levels1. Reduced doses of lansoprazole may be needed when coadministered with voriconazole. Monitor for increased adverse effects associated with lansoprazole 2. Case reports describe the occurrences of cholestatic hepatitis 3 and torsades de pointes with concomitant therapy 4.
Why it happens (mechanism)
Inhibition of CYP2C19-mediated metabolism of lansoprazole; inhibition of CYP3A4-mediated metabolism of lansoprazole
Literature reports
3 reports — tap to read
a) A 44-year-old man taking long-term voriconazole 200 mg twice daily for pulmonary aspergillosis developed cholestatic hepatitis after beginning treatment with lansoprazole. He was also taking predniSONE, trimethoprim/sulfamethoxazole, and insulin. He presented with painless jaundice and fatigue after 10 days of lansoprazole therapy. Liver function tests were as follows: AST 264 milliunits/mL, ALT 362 milliunits/mL, alkaline phosphatase 406 milliunits/mL, total bilirubin 14 mg/dL (240 micromol/L), and direct bilirubin 10 mg/dL (170 micromol/L). These were all normal 1 month prior; hepatitis A, B, and C virus tests were negative. Liver function returned to normal after 4 weeks of stoppage of both voriconazole and lansoprazole, and voriconazole was reintroduced without recurrence of symptoms. The Naranjo score for this interaction was calculated at 7, indicating that cholestatic hepatitis was probably precipitated by lansoprazole 3.
b) A 70-year-old man regularly receiving lansoprazole 30 mg daily experienced recurrent Torsades de Pointes (TdP) 27 days after initiating treatment with voriconazole. The patient was a heterozygous extensive CYP2C19 metabolizer. He was being treated with cytarabine and aclarubicin for acute myeloblastic leukemia; EKG during this phase was normal. On day 14, oral voriconazole 200 mg daily was initiated for invasive aspergillosis. His condition was unremarkable until day 40, when premature ventricular contractions and bigeminy were noted, progressing to TdP with QTc interval of 0.69 seconds. Voriconazole was stopped on day 40, and the patient was rechallenged with voriconazole on day 42 when he became febrile again. The patient had another run of self-limiting TdP on day 44. Despite discontinuation of voriconazole, on day 45 the patient experienced pulseless polymorphic ventricular tachycardia requiring 7 minutes of cardiopulmonary resuscitation. No further attempts were made to treat with voriconazole; his QTc interval normalized within 1 week 4.
c) Voriconazole has been demonstrated to increase systemic exposure to omeprazole (also a proton pump inhibitor (PPI)), via inhibition of CYP2C19 and CYP3A4. Although not specifically evaluated, voriconazole may inhibit the metabolism of other PPIs that are CYP2C19 or CYP3A4 substrates (eg, lansoprazole) and may increase plasma concentrations and adverse events associated with PPIs 2.
Common questions
Can I take Lansoprazole and Voriconazole together?
Increased lansoprazole exposure Always confirm with your pharmacist or prescriber before making any change.
How serious is the Lansoprazole and Voriconazole interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "delayed". Effects tend to build up gradually over days to weeks.
How strong is the evidence for this interaction?
The evidence is graded "probable". Good supporting evidence, though not definitively proven.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Lansoprazole or Voriconazole need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (4)
- Product Information: PREVACID(R) SoluTab(TM) oral delayed-release disintegrating tablets, lansoprazole oral delayed-release disintegrating tablets. Takeda Pharmaceuticals America, Inc (per FDA), Deerfield, IL, 2011. DailyMed
- Product Information: VFEND(R) oral tablets, oral suspension, intravenous injection, voriconazole oral tablets, oral suspension, intravenous injection. Roerig (per FDA), New York, NY, 2025. DailyMed
- Lopez JL & Tayek JA: Voriconazole-induced hepatitis via simvastatin-and lansoprazole-mediated drug interactions: a case report and review of the literature. Drug Metab Dispos 2016; 44(1):124-126. PubMed
- Tsubokura M, Miura Y, Itokawa T, et al: Fatal dysrhythmia following initiation of lansoprazole during a long-term course of voriconazole. J Clin Pharmacol 2011; 51(10):1488-1490. DOI
Keep reading about Voriconazole
Keep reading about Lansoprazole
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Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
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