What is the half-life of loratadine (Loratadine)?

From the Guidelines

The half-life of loratadine is approximately 8 hours. According to the study published in the Journal of Allergy and Clinical Immunology 1, loratadine has a half-life of 8 hours, with its active metabolite, descarboethoxyloratadine, having a half-life of 7.8 to 4.2 hours.

Key Points

• The half-life of loratadine is approximately 8 hours, as indicated in the study 1.
• The active metabolite of loratadine, descarboethoxyloratadine, has a half-life of 7.8 to 4.2 hours.
• Loratadine is typically dosed at 10 mg per day for adults, allowing for once-daily dosing due to its pharmacokinetic profile.
• The long half-life of loratadine and its active metabolite contributes to the drug's extended duration of action, providing 24-hour relief from allergy symptoms with a single daily dose.

Clinical Implications

• The half-life of loratadine is an important consideration in its clinical use, as it allows for convenient once-daily dosing.
• The active metabolite of loratadine also plays a role in the drug's extended duration of action, making it an effective long-acting antihistamine for the treatment of allergies.

From the Research

Half-Life of Loratadine

• The half-life of loratadine is approximately 10 hours, as reported in a study published in 1989 2.
• Another study published in 2010 found that the half-life of loratadine in healthy white Jordanian male volunteers was 3.65 hours, which is shorter than previously reported 3.
• The half-life of the metabolite descarbethoxyloratadine is around 20 hours, as mentioned in the 1989 study 2.
• A 2010 study also reported that the half-life of loratadine in normal adult subjects ranged from 3-20 hours, with a mean of 8.4 hours 3.

Variability in Half-Life

• The half-life of loratadine may vary depending on the population being studied, as seen in the difference between the 1989 study and the 2010 study 2, 3.
• The study published in 2010 found that the population pharmacokinetics of loratadine in healthy white Jordanian male volunteers resulted in a shorter half-life compared to previous research 3.

Comparison with Other Studies

• Other studies, such as those published in 1994 and 1989, do not provide specific information on the half-life of loratadine, but rather focus on its efficacy and pharmacological properties 4, 5, 6.