Are There Any Problems with Second-Generation Antihistamines?
Some second-genereration antihistamines have been reported to cause rare, but serious, irregular heartbeats if they are used in high doses or in combination with certain other medications. These are no longer available in Canada. Although irregular heartbeats have not occurred with Claritin® (loratadine) or Reactine® (cetirizine), always inform your doctor and pharmacist of any over-the-counter antihistamine you are using, and never exceed the recommended dosage. Reactine®, although less sedating than the first-generation antihistamines, is not considered to be a non-sedating antihistamine and you should use caution when driving or operating dangerous machinery if you are taking this medication.
