The comparative study of associations of monte lukast-loratadine versus montelukast-desloratadi ne for the treatment of persistent allergic rhinitis published in this issue showed the non-inferiority of the second option in relation to the comparator.

It should be noted that the prevalence of persis tent allergic rhinitis in Mexico is high, reaching up to 48% in some regions, so the sample size in this study is not significant, a fact to take into account for the conclusions.

But, considering that the advantages of deslo ratadine over loratadine are not relevant, and that they also have a similar profile of adverse and un wanted effects, the combination of either of them with montelukast allows for a similar outcome, just as it happened.

Although desloratadine is a more recently devel oped molecule, with greater dose-related potency of action (5 mg is equivalent to 10 mg of loratadine) and differences in its half-life, its effects on persis tent allergic rhinitis are not significantly different, as most of those who treat this condition have been able to confirm from their clinical experience.

Furthermore, within the arsenal of second-gen eration antihistamines, both in monotherapy and in combination, the choice of drugs for a specific patient should be guided primarily by evaluating their previous experience with such drugs and their response to them, which can be highly vari able. This suggests that regardless of the chosen molecule, there is great individual variation in response.

Therefore, when choosing an antihistamine for the treatment of persistent allergic rhinitis, wheth er it is a first or second-line drug, or combined with montelukast, as in this case, or associated with corticosteroids or decongestants, the same principle applies. The patient’s previous response to the medication is the first factor to consider. In the absence of such information, the choice of the antihistamine should be based on the clinical experience or preference of the treating physician.

A second factor to take into account when choosing an antihistamine is its cost, since there can be considerable differences between drugs, with more recently developed molecules typically being more expensive.

Therefore, it is reasonable to expect this cost difference to be present in the combination with montelukast, resulting in a more expensive prod uct overall.

The economic factor will have greater or lesser importance in each country depending on the local prices of the products and the percentage of the price borne by patients, according to the health coverage they have to access the drugs.

Clearly, the economic factor will be more rel evant in cases where the patient does not have health coverage for his/her medication, so it would be a good practice to consider the cost of the an tihistamine when making the choice.

While it is not common to consider the factors mentioned in research studies, it would be advis able when making a therapeutic decision to con sider statistically significant data and conclusions, as well as the individual history of the patient, and the cost of different treatment alternatives in relation to their potential benefit.