How effective is claritin (loratadine) d to help with allergy asthma?

Antihistamines help: Claritin (loratadine) +/- d, zyrtec +/- d, or Allegra +/- d can help with allergy and asthma symptoms caused by allergies to respiratory pollens or other airborne allergens. One should work with his doctor to see which combination of over-the-counter allergy meds and prescription asthma inhalers/pills work the best. A patient will learn over time, what medicines to adjust, depending on how "bad" the air is.

Some: Post nasal drip is a great irritant to asthmatics with allergies. Getting your allergies treated and clearing the mucus from the upper airway works quite well - nasal rinses + nasal steroids. If these don't work for you completely adding Claritin usually helps somewhat.