Background Both indolent systemic mastocytosis and mast cell activation syndrome are considered rare diseases, and in Spain there are no commercial medicines available of sodium cromoglycate without excipients.

Purpose To describe all patients treated with a magistral formula of sodium cromoglycate 200 mg without excipients: indications, concomitant therapy and response to therapy are reported.

Material and methods We ran a descriptive study in which we included all patients treated with a magistral formula of sodium cromoglycate 200 mg without excipients. The data were obtained through the magistral formulas programme, outpatient dispensation programme and review of medical records. From each patient we extracted data on sex, age, diagnosis, duration of treatment with the formula, dose received, response to therapy, concomitant antihistamine treatment and adverse effects.

Results 8 patients were treated with a magistral formula of sodium cromoglycate 200 mg without excipients: 2 women and 6 men with a mean age of 45.3 years (range 38–59 years). Regarding the indication for the prescription, 3 patients were diagnosed with indolent systemic mastocytosis and the remaining 5 were diagnosed with mast cell activation syndrome. In all cases, the diagnosis was established by examination of the bone marrow in the Mastocytosis Studies Institute of Castilla La Mancha (Spain). On average, patients were treated for 12.75 months (range 3 months to 24 months). The dose received was 200 mg every 8 hours in 7 patients, and was increased to 400 mg three times daily in 1 patient due to a poor response to the therapy. In the remaining patients, the treatment response was optimal. In relation to concomitant antiallergic treatment, 6 patients were receiving fexofenadine daily during the study. No adverse effects related to the therapy were reported.

Conclusion Treatment with this magistral formula of sodium cromoglycate 200 mg without excipients was effective and well tolerated in all patients, improving their symptoms as well as their quality of life, and could be a solution for the lack of marketing of the drug currently in Spain.

No conflict of interest