Dosis bajas de amitriptilina frente a dosis bajas de fluoxetina en el tratamiento de la depresiÓn de enfermos con Parkinson

Introduction. On average 40% of all patients suffering from Parkinson's disease (PD) undergo bouts of depression. It is thought that this is due to a dysfunction in the orbitofrontal and dorsolateral circuits, together with hypometabolism in the orbital, caudate nucleus and frontal dorsolateral tract regions. Aims. The aim of this study is to compare the effectiveness of low doses of fluoxetin with that oflow doses of amitriptyline in controlling depression in patients with PD. Patients and methods. The study examined a total of 77 patients (34 females and 43 males), with an average age of 68.2 years, who had been suffering from PD (according to the diagnostic criteria of Calne et al, in stage II of Hoehn and Yahr) for an average of 6.9 years. They were divided randomly into two groups which received fluoxetin (37 patients, dosage: 20-40 mg/day) or amitriptyline (40 patients, dosage: between 25 and 75 mg/day). A basal evaluation and four others (at 3, 6, 9 and 12 months of treatment) were performed, including the STMS (Short Test of Mental Status), the Hamilton scale, and extent of functional disability using the UPDRS. A statistical analysis was performed by comparing the variance of the above-mentioned parameters and the Χ 2 test with Yates correction or the Fisher exact two-tailed test, to evaluate the reasons for dropping out. In both cases a value ofp< 0.05 was accepted as significant. Results. 58 patients finished the study. Drop-out because of side effects only took place in the group that received amitriptyline (p< 0.02), which was better than fluoxetin at controlling the depression (p< 0.009, 0.001, 0.002 and 0.00006) at 3, 6, 9 and 12 months, respectively. Conclusions. At an average dosage of 35.2 mg/day, amitriptyline is effective in controlling the depression presented by patients with PD. However, despite the low dosage, the side effects it caused forced 15% ofthe patients abandon the treatment.