Pseudoephedrine / terfenadine and Alcohol / Food Interactions
There is 1 alcohol/food/lifestyle interaction with pseudoephedrine / terfenadine:
terfenadine ↔ food
Major Food Interaction
Consumer information for this interaction is not currently available.
CONTRAINDICATED: The consumption of grapefruit juice has been associated with significantly increased plasma concentrations of terfenadine. The mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall induced by certain compounds present in grapefruits. Terfenadine in high serum levels has been associated with prolongation of the QT interval and development of torsade de pointes, a potentially fatal ventricular arrhythmia.
MANAGEMENT: Due to the risk of cardiotoxicity, patients receiving the drug should be advised to avoid consumption of grapefruit products. Loratadine, cetirizine, and fexofenadine may be safer alternatives in patients who may have trouble adhering to the dietary restriction.
- Honig PK, Wortham DC, Zamani K, et al "Terfenadine-ketoconazole interaction: pharmacokinetic and electrocardiographic consequences." JAMA 269 (1993): 1513-8
- Pohjola-Sintonen S, Viitasalo M, Toivonene L, Neuvonen P "Torsades de pointes after terfenadine-itraconazole interaction." BMJ 306 (1993): 186
- Zimmermann M, Duruz H, Guinand O, et al "Torsades de Pointes after treatment with terfenadine and ketoconazole." Eur Heart J 13 (1992): 1002-3
pseudoephedrine / terfenadine drug Interactions
There are 537 drug interactions with pseudoephedrine / terfenadine
pseudoephedrine / terfenadine disease Interactions
There are 6 disease interactions with pseudoephedrine / terfenadine which include:
Drug Interaction Classification
The classifications below are a general guideline only. It is difficult to determine the relevance of a particular drug interaction to any individual given the large number of variables.
|Major||Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit.|
|Moderate||Moderately clinically significant. Usually avoid combinations; use it only under special circumstances.|
|Minor||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.|
Do not stop taking any medications without consulting your healthcare provider.
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