Drug Interactions between avapritinib and porfimer
This report displays the potential drug interactions for the following 2 drugs:
- avapritinib
- porfimer
Interactions between your drugs
porfimer avapritinib
Applies to: porfimer and avapritinib
GENERALLY AVOID: Patients exposed to photosensitizing agents at the same time as or in the 30 to 90 days following treatment with porfimer may be at an increased risk of a photosensitivity reaction (e.g., erythema, swelling, pruritus, burning sensations, feeling hot, and/or blisters). These agents have each been individually associated with photosensitivity reactions and may have additive effects if used together. Medicinal products with known phototoxic or photoallergic potential include, but are not limited to, hypericin-containing products (e.g., St. John's Wort), griseofulvin, thiazide diuretics, sulfonylureas, phenothiazines, sulfonamides, quinolones, and tetracyclines. Photosensitivity with porfimer is due to residual drug being present in the skin. Porfimer is cleared from a variety of tissues over 40 to 72 hours after treatment, but organs of the reticuloendothelial system (e.g., liver, spleen), skin and the tumor itself retain the drug for a longer period. Patients treated with porfimer will be photosensitive for at least 30 days and possibly up to 90 days or more for patients with hepatic or severe renal dysfunction. In clinical studies of porfimer, photosensitivity reactions occurred in approximately 20% of cancer patients and 69% of high-grade dysplasia in Barrett's esophagus patients.
MANAGEMENT: Use of photosensitizing agents should be avoided for at least 30 days and maybe up to 90 days or longer after porfimer treatment depending on the patient's hepatic function, renal function, and/or ability to tolerate exposure to sunlight. Following treatment with porfimer, patients should follow measures outlined in the product labeling for light and sun exposure. It is important to counsel patients to expose their skin to ambient indoor light as it is not only safe but will help eliminate porfimer through the skin by a process called "photobleaching." Before exposing skin or eyes to direct sunlight or bright indoor light (e.g., examination lamps, dental lamps, operating room lamps, floodlights, halogen lamps, unshaded light bulbs at close proximity, etc.), patients should test for residual photosensitivity as described in porfimer's product labeling.
References
- Hoffman GA, Gradl G, Schulz M, Haidinger G, Tanew A, Weber B (2020) "The frequency of photosensitizing drug dispensings in Austria and Germany: A correlation with their photosensitizing potential based on published literature." J Eur Acad Dermatol Venereol, 34, p. 589-600
- Blakely KM, Drucker AM, Rosen CF (2019) "Drug-induced photosensitivity—an update: Culprit drugs, prevention and management." Drug Saf, 42, p. 827-47
- (2023) "Product Information. Photofrin (porfimer)." Pinnacle Biologicals, Inc.
- Concordia Laboratories Inc. (2023) Photofrin sterile porfimer sodium for injection for intravenous use antineoplastic photosensitizing agent. https://pdf.hres.ca/dpd_pm/00028148.PDF
- Pinnacle Biologics B.V. (2023) Annex I summary of product characteristics https://www.ema.europa.eu/en/documents/product-information/photobarr-epar-product-information_en.pdf
Drug and food interactions
avapritinib food
Applies to: avapritinib
GENERALLY AVOID: Grapefruit juice may increase the plasma concentrations of avapritinib. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruit. Inhibition of hepatic CYP450 3A4 may also contribute. The interaction has not been studied with grapefruit juice, but has been reported for other CYP450 3A4 inhibitors. Based on pharmacokinetic modeling, administration of avapritinib (300 mg once daily) in combination with the potent CYP450 3A4 inhibitor itraconazole (200 mg once daily) is predicted to increase avapritinib systemic exposure (AUC) by 600% at steady state, while administration with the moderate CYP450 3A4 inhibitor fluconazole (200 mg once daily) is predicted to increase avapritinib systemic exposure (AUC) by 210% at steady state. In general, the effect of grapefruit juice is concentration-, dose- and preparation-dependent, and can vary widely among brands. Certain preparations of grapefruit juice (e.g., high dose, double strength) have sometimes demonstrated potent inhibition of CYP450 3A4, while other preparations (e.g., low dose, single strength) have typically demonstrated moderate inhibition. Increased exposure to avapritinib may increase the risk and/or severity of serious adverse effects such as intracranial hemorrhage, cognitive impairment, mood disorders, hallucinations, edema, and decreases in hemoglobin, leukocytes, neutrophils, and platelets.
ADJUST DOSING INTERVAL: Food may increase the oral absorption of avapritinib. When avapritinib was administered with a high-calorie, high-fat meal (approximately 909 calories; 58 g carbohydrate, 56 g fat, 43 g protein), avapritinib Cmax and AUC increased by 59% and 29%, respectively, compared to administration in the fasted state.
MANAGEMENT: Avapritinib should be administered on an empty stomach at least 1 hour before or 2 hours after a meal. Patients should avoid consumption of grapefruit and grapefruit juice during treatment with avapritinib.
References
- (2020) "Product Information. Ayvakit (avapritinib)." Blueprint Medicines Corporation
Therapeutic duplication warnings
No warnings were found for your selected drugs.
Therapeutic duplication warnings are only returned when drugs within the same group exceed the recommended therapeutic duplication maximum.
See also
Drug Interaction Classification
Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit. | |
Moderately clinically significant. Usually avoid combinations; use it only under special circumstances. | |
Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan. | |
No interaction information available. |
Further information
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