Why should Circadin® be taken for 21 days? Why up to 3 months? Why not less than 21 days? How many 13-weeks Circadin® treatment courses could a person have in a year?

Circadin^® increases the level of melatonin, facilitating both sleep onset and good quality sleep^{31 30}. However, contrary to CNS-suppressant drugs (BZDs and ‘z’-drugs), and similar to treatment in other disease areas (e.g., depression), the effect on Quality of Sleep is expected to be higher after some days ⁶³ . Therefore, Circadin^® efficacy was measured at baseline, and again after 21 days. It is therefore recommended to take the 21 Circadin^® tablets as a course, and not on an ‘as needed’ basis¹. Treatment may continue with added benefits up to 13 weeks without interruption. The prescribing information and the clinical data do not, at present, support treatment for longer use due to the fact the placebo-controlled phases of the Circadin^® clinical studies have all been of 3 weeks up to 6 months duration^{31 30 1}. Similarly, BZD and ‘z’-drugs are indicated for 2–4 weeks. Long term, open-label studies with Circadin^® have shown that there are no particular safety concerns associated with 6 and even 12 months of treatment^{12 49 11 20}. After the 21-day course, the patient must be evaluated with regard to benefit of treatment and a continued need for medication. Treatment for more than 13 weeks – either continued or as repeated 13-week courses – is ultimately a decision to be made by the treating physician in consultation with the patient, taking into account the benefit of treatment and potential risk.