Taking fexofenadine with fruit juice may significantly reduce its effect
The US’s Food and Drug Administration (FDA) has issued a warning that taking certain medications with fruit juices such as grapefruit juice, may interfere with the action of some drugs. One of these is an antihistamine called Allegra. Allegra is a trade name for fexofenadine and whilst Allergra is not available in the UK, fexofenadine is available as a non-drowsy antihistamine under the brand name Telfast. Research has suggested that drinking the fruit juice before, with or after the medication can significantly reduce its effect. The FDA stated that Fexofenadine may also be less effective if taken with orange or apple juice, so the advice is to avoid taking it with fruit juices:
