Drug Interactions between omeprazole and pemigatinib

Pemigatinib may be taken with or without food. Do not consume grapefruit, grapefruit juice, or any supplements that contain grapefruit extract during treatment with pemigatinib unless directed otherwise by your doctor. Grapefruit juice can increase the blood levels of pemigatinib. This may increase the frequency and severity of serious side effects such as elevated phosphate levels in the blood (which can eventually lead to low blood calcium levels; calcium deposits in the skin, muscles, and other tissues; anemia; muscle cramps; seizures; and irregular heart rhythm), eye and vision problems, joint pain, mouth sores and inflammation, hair loss, diarrhea, nausea, vomiting, and constipation. Talk to your doctor if you have any questions or concerns. 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.

Published observational studies suggest that proton pump inhibitor (PPI) use may be associated with an increased risk of Clostridium difficile-associated diarrhea (CDAD), especially in hospitalized patients. This diagnosis should be considered for diarrhea that does not improve. It is recommended that patients should use the lowest dose and shortest duration of PPI therapy appropriate to the condition being treated. Close monitoring is recommended in patients with diarrhea and in those taking antibacterial agents as CDAD has been reported with the use of nearly all these agents. Treatment with antibacterial agents alters the normal flora of the colon, leading to overgrowth of C. difficile. C. difficile produces toxins A and B, which contribute to the development of CDAD. Appropriate fluid and electrolyte management, protein supplementation, antibiotic treatment of C. difficile, and surgical evaluation should be instituted as clinically indicated.

Published observational studies suggest that proton pump inhibitor (PPI) use may be associated with an increased risk of Clostridium difficile-associated diarrhea (CDAD), especially in hospitalized patients. This diagnosis should be considered for diarrhea that does not improve. It is recommended that patients should use the lowest dose and shortest duration of PPI therapy appropriate to the condition being treated. Close monitoring is recommended in patients with diarrhea and in those taking antibacterial agents as CDAD has been reported with the use of nearly all these agents. Treatment with antibacterial agents alters the normal flora of the colon, leading to overgrowth of C. difficile. C. difficile produces toxins A and B, which contribute to the development of CDAD. Appropriate fluid and electrolyte management, protein supplementation, antibiotic treatment of C. difficile, and surgical evaluation should be instituted as clinically indicated.

The recommended dosage of pemigatinib should be reduced in patients with severe hepatic dysfunction. No dose adjustment is recommended for patients with mild or moderate hepatic impairment.

Symptomatic and asymptomatic hypomagnesemia has been reported rarely in patients treated with PPIs for at least 3 months, in most cases after a year of therapy. Serious adverse events can include tetany, seizures, and arrhythmias. Caution should be used in patients prone to magnesium imbalances such as patients taking other medications that can cause hypomagnesemia (e.g., diuretics). Regular monitoring is recommended.

Various published observational studies have reported that PPI therapy may be associated with an increased risk for osteoporosis related fractures of the hip, wrist or spine. The risk was increased in patients who received high doses (multiple daily doses), and long term treatment (a year or longer). Patients should use the lowest dose and shortest duration of PPI therapy appropriate to the condition being treated. Caution should be used in patients at risk for osteoporosis related fractures and should be managed according to established treatment guidelines.

The recommended dosage of pemigatinib should be reduced in patients with severe renal disease. No dose adjustment is recommended for patients with mild or moderate renal impairment, or those patients with end-stage renal disease receiving intermittent hemodialysis.

Pemigatinib can cause retinal pigment epithelial detachment (RPED), which may cause symptoms such as blurred vision, visual floaters, or photopsia. A comprehensive ophthalmological examination including an optical coherence tomography should be performed prior to treatment initiation. Patients with visual disturbances should be closely monitored.