[Clinical use of sustained release of alprazolam: A naturalistic study]

Alprazolam extended release formulation (Alprazolam XR) is a new formulation with useful features in the treatment of pathological anxiety, when compared both to the original formulation of alprazolam or to other benzodiazepines, as it adds to the well known properties of alprazolam a sustained clinical effect. The available investigational clinical trials show good efficacy for this new formulation. There is the need, however, of observational studies in the clinical setting that confirm its usefulness.

We present an observational prospective naturalistic study of all the pathological anxiety cases that followed treatment with Alprazolam XR in two psychiatry outpatient centres. Sixty-eight (68) patients were included in the study. The treatment period was 21 weeks. In each of the 4 control visits, efficacy (HAMA, GCI, GCI improvement) and tolerability (adverse events) were assessed, as well as the dose, dosage pattern and need of change of the medication.

Global anxiety (HAMA, GCI and CGI improvement) showed a significant reduction throughout the study. There was a reduction in the number of panic attacks and in the severity of agoraphobia. Global clinical impression (efficacy and tolerability) was good or very good in 75% of the patients, both assessed by the investigator and by the patient. Fifty percent (50%) of the patients had an adverse event (mainly sedation), most cases being mild and transient. Fifty-eight percent (58%) of the patients needed a change in the dosage regimen (dose, number of daily doses), mostly due to clinical dose adjustment. Some patients needed a change in the dosage due to adverse events. Sixteen patients that had been treated with the conventional formulation of alprazolam and started treatment with Alprazolam XR needed a slightly higher dose of the extended release formulation. In these cases the change of medication was easy.

The clinical use of Alprazolam XR in the treatment of pathological anxiety was useful in most of the patients (75%). The dose regime was usually 2-3 mg in two daily doses, with a trend to lower the dose (1-2 mg in a single dose) in the third or fourth control. The change from the conventional formulation to the extended release was not difficult in most of the patients.