Can You Take Two Claritin A Day?

In our latest question and answer, the pharmacist discusses the safety of taking two tablets of Claritin daily instead of the recommended dose of one.

Question

Hi, my son aged 25 has taken 2 tablets of Claritin today 6 hours apart. He is fine and not showing any allergic symptoms. Is this okay?

Asked by Ali On Jun 12, 2022

Answered by
Medical Content Reviewed By HelloPharmacist Staff

Published Jun 12, 2022
Last updated Mar 28, 2024

Key points

  • The maximum dose of Claritin (loratadine) recommended for adults is 10mg per day.
  • Claritin can be dosed once daily with a 10mg tablet or twice a day, every 12 hours, with a 5mg tablet.
  • Several studies have reported that loratadine doses up to 40mg per day are generally effective and well-tolerated. However, long-term safety studies and associated data are lacking.
  • If the maximum daily dosage of Claritin (10mg for adults) is ineffective, you may find more relief of allergy symptoms by combining it with a nasal steroid, like Flonase.

Hi Ali and thanks for reaching out!

I am assuming based on your submission you are looking for information on taking 2 tablets of adult Claritin per day, for a total of 20mg.

I'll start off by saying that 10mg of Claritin (loratadine) per day is the maximum dose approved by the FDA (Food and Drug Administration).

However, a number of studies do show that doses above 10mg can be effective, with minimal risk of side effects.

Nevertheless, you likely won't see recommendations or guidance for adults to take over 10mg per day, since, as mentioned, that is the FDA-approved maximum daily dose.

Claritin Recommended Dosing

There are several different dosage forms and strengths of Claritin available. These include:

  • 24-Hour Tablets (10mg)
  • 12-Hour Reditabs (5mg)
  • 24-Hour Reditabs (10mg)
  • 24-Hour Liquigels (10mg)
  • 24-Hour Chewtabs (10mg)

There are also several children's products, which include a 5mg/5mL syrup.

As stated in the section above, the maximum daily dose for Claritin (loratadine) approved by the FDA is 10mg for adults.

This can either be taken as a single dose (10mg every 24 hours) or twice a day (5mg every 12 hours).

The maximum daily dose for children 2 years to 6 years old is 5 mg once daily.

Can You Take Over 10mg Per Day?

To answer the question of whether or not you can take two Claritin per day, we have to clarify what is actually being asked.

For adults, you can take Claritin 5mg twice a day, since the 5mg dose is intended to work for 12 hours at a time. This is within the recommended dosing guidance.

However, most people that ask about taking two Claritin a day are referring to taking two 10mg doses (which, again, is over the maximum recommended dose).

So, in regard to this, taking over 10mg per day, there have been quite a few studies testing the safety and effectiveness of doses up to 40mg per day.

One such study reported the following:

loratadine 40 mg once daily was effective and safe in the relief of symptoms of allergic rhinitis.
J Int Med Res . Mar-Apr 1987;15(2):63-70

This study particularly noted there were no significant side effects experienced in those taking loratadine at that high dose (40mg).

Another study tested doses up to 80mg per day and noted increasing effectiveness as the dose increased, with minimal side effects. It reported the following results:

The mean suppression [of an allergic reaction] over 48 hours was 16% in placebo-treated subjects and 35%, 45%, 51%, and 67% in the 10, 20, 40, and 80 mg loratadine-treated subjects, respectively. The onset of action occurred within the first hour. Duration of suppression was dose related, ranging from 12 hours with the lowest dose (10 mg) to 48 hours with the higher doses (40 and 80 mg).
Ann Allergy . 1988 Jun;60(6):505-7.

It is important to note that not every study reports loratadine being well-tolerated at doses over what is recommended. 

Many have reported that 40mg per day seems to be the dose where side effects start becoming particularly noticeable. These side effects include:

  • Sedation
  • Increased heart rate
  • Headache
  • Nausea
  • Vomiting
  • Increased blood pressure

For most people, 10mg per day of Claritin is plenty to be effective. If you are still struggling with symptoms, it may be a better idea to try something else, or in addition to Claritin, instead of taking over the dosage recommended.

Final Words

Overall, loratadine is generally regarded as a safe antihistamine, with toxic doses being well above the recommended daily doses.

The side effects of the drug appear to be dose-dependent, meaning they occur more frequently, and are more severe, as you increase your dose.

Most of the evidence points to 20mg of Claritin (two tablets per day of the adult 10mg dose) being relatively safe and effective.

The issue is that this is above the maximum recommended dose approved by the FDA, and even though there are some studies showing doses above 10mg are, for the most part, safe, there is a lack of long-term safety data.

Most individuals respond very well to 10mg per day, and if you find yourself needing additional relief, you should talk to your doctor about your options.

Many times, adding on a nasal steroid, like Flonase Nasacort or Nasonex, to an antihistamine, can be more effective than taking either alone.

References

  • Loratadine (SCH29851) 40 mg once daily versus terfenadine 60 mg twice daily in the treatment of seasonal allergic rhinitis, PubMed
  • Effects of loratadine (SCH 29851) in suppression of histamine-induced skin wheals, PubMed
  • Loratadine Monograph, PubChem
  • Treatment of allergic rhinitis: H1-antihistamines and intranasal steroids, PubMed

About the Pharmacist

Dr. Brian Staiger, PharmD

Dr. Brian has been practicing pharmacy for over 13 years and has wide-ranging experiences in many different areas of the profession. From retail, clinical, program development, and administrative responsibilities, he's your knowledgeable and go-to source for all your pharmacy and medication-related questions! Dr. Brian Staiger also has herbalist training and educational certificates in the field of medical ethnobotany. Feel free to send him an email at [email protected]! You can also connect with Dr. Brian Staiger on LinkedIn.

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