Allegra vs Plan B: side-by-side comparison
Allegra (Allergies et antihistaminiques) and Plan B (Hormones et contraception) belong to different therapeutic classes and are rarely interchangeable. This page compares the medications' purposes, mechanisms and the situations where each is used.
| Property | Allegra | Plan B |
|---|---|---|
| Active ingredient | Fexofenadine | Levonorgestrel |
| Manufacturer | Sanofi | Foundation Consumer Healthcare |
| Class | Allergies et antihistaminiques | Hormones et contraception |
| Strengths | 30mg, 60mg, 120mg, 180mg | 1.5mg |
| Forms | tablet, oral suspension, orodispersible tablet | tablet |
What's the same
Allegra and Plan B are used in very different patients, and the points in common are limited. The main shared element is that both meet regulatory standards for efficacy and safety and benefit from pharmacist oversight.
Key differences
Allegra belongs to Allergies et antihistaminiques while Plan B belongs to Hormones et contraception. Indications, mechanisms and target populations differ. The comparison is most useful when a clinician has mentioned both medications and the patient wants to understand where each fits.
Mechanism and action
Allegra: La fexofénadine bloque sélectivement les récepteurs H1 périphériques de l'histamine, antagonisant ses effets sur la vasodilatation, la perméabilité capillaire, les terminaisons nerveuses sensitives et le muscle lisse. Plan B: Le mécanisme principal de Plan B est le retard ou le blocage de l'ovulation lorsqu'il est pris avant le pic de LH.
When Allegra is preferred
Allegra est autorisé chez l'adulte et l'enfant dans le traitement de la rhinite allergique saisonnière et de l'urticaire chronique idiopathique.
When Plan B is preferred
Plan B est indiqué en contraception d'urgence après un rapport non protégé ou un échec de contraception avéré ou suspecté, chez la femme en âge de procréer.
Questions fréquentes
Is Allegra or Plan B better? ▾
Allegra and Plan B are not interchangeable — they treat different conditions. Asking which is "better" is meaningful only when a clinician has weighed both for the same specific clinical scenario.
Can I switch from Allegra to Plan B? ▾
Switching between Allegra and Plan B is rarely an appropriate decision since they belong to different classes and treat different conditions. The real question is usually whether the diagnosis calls for one medication or the other — which the prescriber resolves.
Do Allegra and Plan B have the same side effects? ▾
No — they belong to different classes and have distinct side-effect profiles. Each medication has its own prescribing information.
More Allegra comparisons
Les informations publiées sur ce site sont fournies à titre documentaire et pédagogique. Elles ne remplacent pas l'avis d'un professionnel de santé qualifié.