Omeprazole Delayed-Release Capsules and Tablets (OTC) and Vfend

In the database of official manuals used in the service creation an interaction registered by statistical results of studies was found, which can either lead to negative consequences for the patient health or strengthen a mutual positive effect. A doctor should be consulted to address the issue of joint drug administration.

Voriconazole can increase the blood levels of omeprazole. This may increase side effects such as diarrhea, abdominal pain, nausea, vomiting, and flatulence. During long-term treatment, you may also have an increased risk of developing osteoporosis, bone fractures, and a condition called hypomagnesemia (low blood magnesium), which in severe cases can lead to muscle spasm, irregular heart rhythm, and seizures. Talk to your doctor if you have any questions or concerns. Your doctor may be able to prescribe alternatives that do not interact, or you may need a dose adjustment or more frequent monitoring by your doctor to safely use both medications. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

ADJUST DOSE: Coadministration with voriconazole may significantly increase the plasma concentrations of omeprazole and other proton pump inhibitors (PPIs). The proposed mechanism is voriconazole inhibition of PPI metabolism via CYP450 2C19 and 3A4. In healthy volunteers, administration of omeprazole 40 mg once daily with voriconazole 200 mg twice daily for 7 days increased steady-state omeprazole peak plasma concentration (Cmax) and systemic exposure (AUC) by an average of 2- and 4-fold, respectively, compared to omeprazole administered alone. Since all PPIs are metabolized by CYP450 2C19 and 3A4, a similar interaction with voriconazole should be expected.

MONITOR: Omeprazole and possibly other PPIs may also increase the plasma concentrations of voriconazole. The proposed mechanism is PPI inhibition of voriconazole metabolism via CYP450 2C19 and 3A4. In 18 healthy volunteers, administration of voriconazole 200 mg twice daily with omeprazole 40 mg once daily for 10 days increased the steady-state Cmax and AUC of voriconazole by an average of 15% and 41%, respectively, compared to administration with placebo. These changes are not generally considered clinically significant. However, an observational study of 52 voriconazole patients who received therapeutic drug monitoring reported that 5 out of 16 patients with voriconazole trough levels above 5.5 mg/L after one week of therapy experienced serious neurological adverse events (compared to none of the patients with lower trough levels), and 7 of the 16 were on concomitant omeprazole. Additionally, a suspected interaction between omeprazole and voriconazole was cited as a possible cause, or at least a contributing factor, in the development of torsade de pointes and cardiac arrest in the case of a young girl with congenital long QT syndrome.

MANAGEMENT: According to the manufacturers, dosage adjustment of omeprazole is not normally required when used with dual inhibitors of CYP450 2C19 and 3A4 such as voriconazole. However, it may be necessary in patients receiving higher dosages, such as those with Zollinger-Ellison syndrome. Voriconazole product labeling suggests reducing the omeprazole dosage by one-half upon initiation of voriconazole therapy in patients who are receiving omeprazole dosages of 40 mg/day or higher. Dosage adjustment recommendations for other PPIs are not available. Patients receiving PPIs with voriconazole should be monitored for potentially increased adverse reactions to both the PPI and voriconazole.

Omeprazole Delayed-Release Capsules and Tablets (OTC)

Generic Name: omeprazole

Brand name: FIRST Omeprazole, Omeprazole + SyrSpend SF Alka, Prilosec, Prilosec OTC, Zegerid>, Prilosec, Prilosec OTC

Synonyms: Omeprazole

What is Omeprazole Delayed-Release Capsules and Tablets (OTC)?

Vfend

Generic Name: voriconazole

Brand name: Vfend, Vfend

Synonyms: Vfend Injection

What is Vfend?