Taking Claritin With Zyrtec

In our latest question and answer, the pharmacist discusses whether or not Claritin (loratadine) can be taken with Zyrtec (cetirizine).

Feb 16, 2018

Beatrice asked

Can you take Claritin and Zyrtec together? I have bad allergies! Is using both safe?


Claritin (loratadine) and Zyrtec (cetirizine) are both second generation antihistamines used in the treatment of allergy symptoms such as sneezing, runny nose and watery and itchy eyes. They should not be taken together as it would be a duplication in therapy and it would be unlikely that you would get any additional benefit by taking more than one. Also, there may be an increased risk of side effects when using both together, including:

  • Sedation
  • Dry mouth
  • Dry eyes
  • Constipation
Claritin Vs. Zyrtec

Claritin (loratadine) typically works within 1-3 hours and lasts for 24 hours.  Zyrtec (cetirizine) typically has a slightly faster onset of action of about an hour and also lasts for 24 hours.  While both antihistamines are second generation antihistamines that typically cause less sedation or drowsiness than older, first generation antihistamines, Zyrtec (cetirizine) has a higher incidence of patients reporting problems with drowsiness.  

Other Options For Allergy Relief

If allergy symptoms are still a problem after taking either Claritin (loratadine) or Zyrtec (cetirizine) for 1 week, it may be helpful to add an over the counter (OTC) nasal steroid spray such as Nasacort Allergy 24HR (triamcinolone nasal) or Flonase Allergy Relief (fluticasone nasal).  These medications are used nasally in the treatment of allergy symptoms like runny, itchy nose, congestion and sneezing.  Relief of symptoms may not fully be seen for 1 week from the start of using these nasal sprays.  They are generally well tolerated medications with the side effects of nasal irritation, bleeding or sneezing being the most reported.  Both Nasacort Allergy 24HR (triamcinolone nasal) and Flonase Allergy Relief (fluticasone nasal) can be used together with either Claritin (loratadine) or Zyrtec (cetirizine).  Should relief not be felt after adding one of these medications to either Claritin (loratadine) or Zyrtec (cetirizine), then it is time to talk to your doctor or primary health care provider.


Claritin (loratadine) and Zyrtec (cetirizine) should not be taken together as they are both in the same class of medication. Using both Claritin and Zyrtec may increase the risk of side effects and likely won't help relieve your allergies any more than either one alone. If you need additional relief after taking Claritin or Zyrtec, adding an OTC nasal steroid spray like Nasacort Allergy 24HR (triamcinolone nasal) or Flonase Allergy Relief (fluticasone nasal) may help with the relief of allergy symptoms. 

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