Less sedating than
Zyrtec is 3.5 times more likely than Claritin to cause sedation, particularly when used at dosages higher than 10mg/day.
However, Zyrtec is still much less sedating than older antihistamines such as promethazine.
Cetirizine was significantly more likely than loratadine to cause drowsiness and have a negative effect on motivation in one study of 60 patients with allergic rhinitis. Trials have shown both Zyrtec and Claritin are significantly more effective than placebo (a pretend pill) for reducing symptoms associated with allergic rhinitis, hay fever, and other allergies.
Trials have not consistently shown that one antihistamine is more effective than another, although one trial did report cetirizine reducing symptoms to a greater extent.
Intranasal or ophthalmic (into the eye) antihistamines have a quicker onset of action than oral antihistamines (within about 15 minutes); however, need to be administered several times daily.
In people with allergic rhinoconjunctivitis and predominantly eye symptoms, ophthalmic antihistamines work much quicker (within 3 to 15 minutes) and are much more effective than any other form of treatment.
Zyrtec Vs Claritin: Administration The antihistamine effects of Zyrtec and Claritin last for at least 24 hours, therefore, they are both given once daily.
Zyrtec is a brand name for the drug cetirizine and Claritin is a brand name for the drug loratadine.
Both cetirizine and loratadine are popular antihistamines with many similarities but there are some important differences. Zyrtec or Claritin Zyrtec (cetirizine) and Claritin (loratadine) are second-generation antihistamines.
Thin postnasal drip secretions caused by allergies may be treated with antihistamines.
Second-generation antihistamines such as Zyrtec and Claritin may offer better relief than older-type antihistamines such as promethazine (older antihistamines tend to thicken post-nasal secretions).