Written by Mita Majumdar, M.Sc. | 
Medically Reviewed by dr. simi paknikar, MD on Nov 18, 2019

Over-the-Counter (OTC) Antihistamines Drugs for Allergy

Second generation over-the-counter antihistamines cause less side effects like drowsiness.

Over-the-counter antihistamines are available in the form of first generation and second generation antihistamines.(3)

First generation OTC anti-histamines for allergies (active ingredients and brand names):

Second generation OTC anti-histamines for allergies (active ingredients and brand names):

  • Loratadine Claritin
  • Cetirizine Zyrtec

Indications sneezing, itching, watery eyes and runny nose and hives.

Contraindications discontinue use and seek medical attention if serious allergic reaction occurs.


Cetirizine (Zyrtec): Tablet - 5-10 mg orally once a day depending upon symptom severity. Syrup 5 mg/ 5 mL

Loratadine (Claritin, Tavist), Brompheniramine (Dimetane): Tablet 10mg once daily for adults, 5 mg once daily for children 2 to 5 years.

Chlorpheniramine (Chlor-Trimeton) 4 mg orally every 4 - 6 hrs; sustained-release: 8 or 12 mg orally every 8 - 12 hours. Maximum dose: 24 mg/day.

Diphenhydramine (Benadryl): 25 mg to 50 mg (1-2 capsules) per day for adults and children above 12 years; for children 6 -12 years of age 25 mg (1 capsule)

Side effects drowsiness especially in case of first-generation antihistamines, restlessness, nervousness, upset stomach, dry mouth, irritability, difficulty urinating and sometimes blurred vision.

Precautions and Warnings:

  • Second-generation antihistamines are less likely to interact with other drugs like sedatives
  • Do not use antihistamines in large amounts or for longer than recommended.
  • Use alcohol cautiously if you are on antihistamines
  • While taking antihistamines, do not drive or use machinery that could harm you if you are not alert
Precautions with Over-the-Counter Drugs


  1. Choosing an Over-The-Counter Allergy Medication - (https://www.health.harvard.edu/diseases-and-conditions/choosing-an-over-the-counter-allergy-medication)
  2. The Best Over-the-Counter Allergy Medications - (https://www.verywellhealth.com/choosing-over-the-counter-allergy-treatment-3859664)
  3. Popular Over-the-Counter Oral Antihistamine Brands - (https://www.healthline.com/health/allergies/antihistamine-brands#second-and-thirdgeneration-brands)
  4. Decongestants: OTC Relief for Congestion - (https://familydoctor.org/decongestants-otc-relief-for-congestion/)
  5. What Is Pseudoephedrine? - (https://www.verywellhealth.com/what-is-pseudoephedrine-1192197)
  6. What is Hydrocortisone? - (https://www.everydayhealth.com/drugs/hydrocortisone)

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