Kyvin asked
How long does Claratin (Loratadine) last?
Answer
Claritin is typically dosed once daily and the antihistamines effects generally last around 24 hours. Studies have shown that after dosing, it takes about 1-3 hours to notice the medication working and the peak effects of the drug are seen after 8-12 hours.
We commonly get asked which antihistamine lasts the longest. While you really can't go wrong with any over the counter second generation antihistamines (Allegra, Zyrtec, Claritin, Xyzal) since they generally last for a 24 hour period. Studies have shown however, that Zyrtec (cetirizine) and Xyzal tend to have better effects for longer periods of time. For example, one study showed that allergy symptoms in those with seasonal allergies had their symptoms reduced for a longer period of time with Zyrtec and Xyzal than with the other antihistamines.
One important note is that Claritin (Loratadine) tends to be the least expensive of the second generation antihistamines and since it lasts 24 hours and is non-drowsy, it is a good first choice if you haven't tried anything before.
Duration Of Action: ~ 24 hours per dose
Onset Of Action: 1-3 hours
Peak Effect: in 8—12 hours
Half-Life: 8 hours (metabolite ~28 hours)
Children: Half-life similar to adults
Elderly: Half-life prolonged ~ 50% when compared to adults
Typical Dose: 10mg once daily
