patients on Allegra who say it doesn't work
If you have patients on Allegra who say it doesn't work, maybe it's because they take it with fruit juice.
Preliminary evidence suggests the bioavailability of Allegra is almost 70% less when taken with apple, orange, or grapefruit juice.
This is completely different from the usual grapefruit juice interactions. Grapefruit inhibits cytochrome P450 enzymes and INCREASES absorption of certain drugs...lovastatin, nifedipine, etc.