What's the best allergy medicine? allegra, claritin (loratadine) or zyrtec?

All of them: Some patients have a preference related to efficacy, but most patients find they are each helpful and often make decisions based on price. Zyrtec and Allegra are a bit stronger whereas Claritin (loratadine) seems to be active longer. Zyrtec might be slightly more potent with faster onset of effect and it is usually my first suggestion

Allergies: Allegra (fexofenadine) or Zyrtec are best with less side effects

Depends, somewhat: Pollen chamber study done yrs ago typical: when pollen blown directly into the faces of allergic patients, both measured symptoms and patient complaints show Zyrtec better, faster; Claritin (loratadine) slower, worse. Allegra, a close 2nd. But: FDA felt only Zyrtec was effective enough to advertise for animal allergies (remember the barking dog in the ad?). Note: I'm not affiliated with any of these products.

Pretty much the same: They are all long acting antihistamine and are pretty much the same. The onset of acting is a little different with 1-3 hours for Claritin (loratadine) and faster for others. In some individuals, Zyrtec may cause drowsiness while this side effect does not see with the other two.

All 3 are good: Claritin 10 mg is only as good as Chlorfeniramine 4 mg the most effective dose is 20 mg for adults but that causes 12-14% of people to become drowsy. Zyrtec 10mg causes same level of drowsiness but controls skin , eye and nasal itching. Allegra at 180mg does not cause significant drowsiness but is as effective as Zyrtec. Allegra is very safe it has been tested at twice/day for hives.

Patient dependent: Allegra (fexofenadine), Claritin (loratadine), and Zyrtec (cetirizine) are all wonderful non-sedating second generation antihistamines that selectively antagonize peripheral histamine H1receptors. They are good for relieving allergic rhinitis (sneezing, itchy/watery eyes, and itchy nose/throat). I believe patients should choose the best medicine to take by trial-and-error.

Allergy medicines: It is often a personal choice based on risks/benefits and indication. Allegra and Claritin (loratadine) are marketed as non-sedating. The package label for Zyrtec suggests about 10% of people can have sedation with Zyrtec, but in some settings, Zyrtec may have more effect. Price is also a factor. It is not uncommon for antihistamines to lose benefit with time due to a phenomenon called allergy priming.

Same effects: These three medications do the same thing and are not supposed to make you drowsy, however, Zyrtec seems to work somewhat better than Allegra and Claritin. I would say Claritin is the least effective out of these three medications.