From the Guidelines
Allegra (fexofenadine) should be discontinued at least 3 days before an oral food challenge (OFC) to avoid interference with interpretation of the results, as suggested by the guidelines for discontinuation of medications that might interfere with OFC interpretation 1. When considering discontinuing Allegra, it's essential to note that the medication can be stopped abruptly without tapering, as it does not cause withdrawal symptoms. However, allergy symptoms may return within 1-3 days after stopping the medication.
- Key points to consider when discontinuing Allegra include:
- The medication's effects typically last for 24 hours, after which the blocking effect on histamine receptors ends, and symptoms may return if the underlying allergic trigger is still present.
- If Allegra is being taken for a chronic condition under a doctor's supervision, it's best to consult with the healthcare provider before discontinuing, especially if it's part of a comprehensive allergy management plan.
- The guidelines for discontinuation of medications before an OFC suggest stopping oral antihistamines, including fexofenadine, 3-10 days before the challenge 1.
- It's crucial to weigh the risks of drug withdrawal and consider alternative treatments, as well as avoid certain medications like aspirin and nonsteroidal anti-inflammatory agents that may enhance or induce allergic reactions 1.
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Discontinuing Allegra
- Discontinuing Allegra, also known as fexofenadine, may be considered when sedation is a concern, as newer antihistamines like fexofenadine provide similar efficacy to first-generation antihistamines but with less sedation 2.
- A study comparing fexofenadine to loratadine found that fexofenadine was more effective in suppressing histamine-induced flares and wheals, with a faster onset of action 3.
- When discontinuing chronic medication like Allegra, it is essential to consider the feasibility and safety of discontinuation, as well as the potential for relapse of symptoms 4.
- Fexofenadine has been shown to have no effect on muscarinic receptor activation, unlike some other antihistamines like desloratadine and diphenhydramine 5.
- A comparative review of desloratadine, fexofenadine, and levocetirizine found that these second-generation antihistamines have a high affinity for the H1 receptor and a limited effect on the CNS, with minimal drug-drug interactions and no major cytochrome P450 inhibition 6.
Potential Effects of Discontinuation
- The proportion of patients who successfully stop their medication varies from 20% to 100%, and the range of reported relapse varies from 1.9% to 80% 4.
- Fexofenadine does not impair psychomotor or cognitive skills and shows no dose-related increase in sedation 2.
- Desloratadine, fexofenadine, and levocetirizine are all efficacious treatments for allergic rhinitis and chronic idiopathic urticaria, with differences in their pharmacological characteristics and clinical endpoints 6.