Question: what is the difference between zyrtec and claritin d?
Answer: by Drugs.com The difference is Zyrtec is more likely to cause sedation than Claritin. Zyrtec also has a quicker onset of action (one hour vs up to three hours for Claritin) but both last for 24 hours. Zyrtec is a brand name for the drug cetirizine and Claritin is a brand name for the drug loratadine.