Drug Interactions between amiodarone and methoxsalen
This report displays the potential drug interactions for the following 2 drugs:
- amiodarone
- methoxsalen
Interactions between your drugs
amiodarone methoxsalen
Applies to: amiodarone and methoxsalen
MONITOR: Concomitant use of methoxsalen with other known photosensitizing agents may increase the risk of photosensitivity reactions. These agents include anthralin, coal tar or coal tar derivatives, griseofulvin, hypericin extracts (e.g., St John's Wort), fluoroquinolones, phenothiazines, retinoids, halogenated salicylanilides (bacteriostatic soaps), sulfonamides, sulfonylureas, tetracyclines, thiazides, and certain organic staining dyes such as methylene blue, toluidine blue, rose bengal, and methyl orange.
MANAGEMENT: Caution is advised and pharmacologic response to methoxsalen therapy should be carefully monitored if concomitant use of other photosensitizing agents cannot be avoided. Patients should be advised to avoid sun exposure, even through window glass or cloud cover, for at least 8 hours after methoxsalen ingestion and during the 24 hours following photochemotherapy or photopheresis treatment. Protective devices should be used if sun exposure cannot be avoided, such as a hat and gloves and/or sunscreens containing ingredients that filter out UVA radiation (e.g., benzophenone and/or PABA esters). Sunscreens must be applied to all areas that might be exposed to the sun, including the lips. For the treatment of psoriasis, sunscreens should not be applied to areas affected by psoriasis until after treatment in the UVA chamber. In addition, UVA-absorbing wrap-around sunglasses should be worn during daylight for 24 hours after methoxsalen ingestion and during the 24 hours following photochemotherapy or photopheresis treatment to prevent the irreversible binding of methoxsalen to proteins and DNA components of the lens, which can lead to formation of cataracts. The glasses should be worn any time patients are exposed to direct or indirect sunlight, whether they are outdoors or exposed through a window. Because erythema and/or burning due to photochemotherapy and sunburn due to sun exposure are additive, patients should not sunbathe for 48 hours after photochemotherapy.
References (8)
- "Multum Information Services, Inc. Expert Review Panel"
- (2001) "Product Information. Oxsoralen (methoxsalen)." ICN Pharmaceuticals Inc
- 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. Uvadex (methoxsalen)." Therakos (UK) Ltd
- (2019) "Product Information. Methoxsalen (methoxsalen)." Strides Pharma Inc.
- (2021) "Product Information. Uvadex (methoxsalen)." Therakos Inc
- Ikaria Australia Pty Ltd (2023) Australian product information - uvadex (methoxsalen) concentrated injection. https://www.ebs.tga.gov.au/ebs/picmi/picmirepository.nsf/pdf?OpenAgent=&id=CP-2022-PI-02125-1&d=20230530172310101
Drug and food interactions
amiodarone food
Applies to: amiodarone
GENERALLY AVOID: Grapefruit juice may significantly increase the plasma concentrations of orally administered amiodarone. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruits. In 11 nonsmoking, healthy volunteers, grapefruit juice (300 mL with drug administration, then 3 hours and 9 hours later) increased the mean peak plasma concentration (Cmax) and area under the concentration-time curve (AUC) of amiodarone (17 mg/kg single dose) by 84% and 50%, respectively, compared to water. Formation of the pharmacologically active metabolite, N-desethylamiodarone (N-DEA), was completely inhibited. Clinically, this interaction can lead to altered efficacy of amiodarone, since antiarrhythmic properties of amiodarone and N-DEA appear to differ. In the study, mean increases in PR and QTc intervals of 17.9% and 11.3%, respectively, were observed 6 hours postdose with water, while increases of 10.2% and 3.3%, respectively, were observed after administration with grapefruit juice.
ADJUST DOSING INTERVAL: Food increases the rate and extent of absorption of amiodarone. The mechanism appears to involve the effect of food-induced physiologic changes on drug release from its formulation. In 30 healthy volunteers, administration of a single 600 mg dose of amiodarone following a high-fat meal resulted in a Cmax and AUC that were 3.8 and 2.4 times the respective values under fasting conditions. The time to reach peak plasma concentration (Tmax) was decreased by 37%, indicating an increased rate of absorption. Mean Cmax and AUC for the active metabolite, N-DEA, also increased by 32% and 55%, respectively, but there was no change in the Tmax.
MANAGEMENT: Patients treated with oral amiodarone should avoid consumption of grapefruits and grapefruit juice. In addition, oral amiodarone should be administered consistently with regard to meals.
References (3)
- (2002) "Product Information. Cordarone (amiodarone)." Wyeth-Ayerst Laboratories
- Libersa CC, Brique SA, Motte KB, et al. (2000) "Dramatic inhibition of amiodarone metabolism induced by grapefruit juice." Br J Clin Pharmacol, 49, p. 373-8
- Meng X, Mojaverian P, Doedee M, Lin E, Weinryb I, Chiang ST, Kowey PR (2001) "Bioavailability of Amiodarone tablets administered with and without food in healthy subjects." Am J Cardiol, 87, p. 432-5
methoxsalen food
Applies to: methoxsalen
GENERALLY AVOID: The ingestion of foods containing photosensitizing components (e.g., limes, figs, parsley, parsnips, rue (Ruta graveolens), mustard, carrots and celery) may increase the risk of photosensitivity and severe burning during methoxsalen therapy. Two cases of photosensitivity involving rue and a soup containing celery, parsley, and parsnip have been reported in PUVA patients.
MANAGEMENT: Patients who are undergoing PUVA treatment and taking methoxsalen should be advised to avoid eating large quantities of these foods.
References (1)
- the Australasian Society of Clinical and Experimental Pharmacologists and Toxicologists (ASCEPT), Royal Australian College of General Practicioners (RACGP), the Pharmaceutical Society of Australia (PSA) (2007) Australian Medicines Handbook. https://www.amh.net.au/
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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