Pharmacoeconomics of antidepressants in moderate-to-severe depressive disorder in Colombia.
OBJECTIVE
To compare three antidepressant drugs from different classes used in treating moderate-to-severe major depressive disorder (MDD) in Colombian adults.


METHODS
Based on expert input, a decision-tree model was adapted for Colombia to analyze data over 6 months from the government-payer perspective. The cost-effectiveness of amitriptyline, fluoxetine, and venlafaxine was determined. The clinical outcome was remission of depression (a score <or=7 on the Hamilton Depression [HAM-D] scale or <or=12 on the Montgomery-Asberg Depression Rating Scale [MADRS]) after 8 weeks of treatment. Clinical data were obtained from the literature and costs from standard Colombian price lists. One-way and multivariate sensitivity analyses tested model robustness.


RESULTS
Costs per patient (in 2007 US$) for treatment were: venlafaxine, $1,618; fluoxetine, $1,207; and amitriptyline, $1,068. Overall remission rates were 73.1%, 64.1%, and 71.3%, respectively. Amitriptyline dominated fluoxetine (i.e., it had lower costs and higher outcomes). The incremental cost-effectiveness ratio (ICER) of venlafaxine over amitriptyline was US$ 31,595. The acquisition price of venlafaxine was the model's cost driver, comprising 53.4% of the total cost/patient treated, compared with 18.5% and 24.8% for fluoxetine and amitriptyline, respectively. For the others, hospitalization comprised the major cost (72.1% and 65.2%, respectively). Probabilistic (Monte Carlo) sensitivity analysis confirmed the original findings of the pharmacoeconomic model.


CONCLUSIONS
Amitriptyline is cost-effective in comparison to fluoxetine and venlafaxine in Colombia. However, the cost of venlafaxine was estimated for the brand-name product, as generics were not currently available. These cost-effectiveness results can be substantially affected by the presence of generics or drug cost regulations.
Machado
Márcio
M
Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada. m.machado@utoronto.ca
Lopera
Monica Maria
MM
Diaz-Rojas
Jorge
J
Jaramillo
Luis Eduardo
LE
Einarson
Thomas Ray
TR
D000639:Amitriptyline / Q000191:economics* / Q000627:therapeutic use; D000928:Antidepressive Agents / Q000191:economics* / Q000627:therapeutic use; D003105:Colombia / Q000453:epidemiology; D003295:Convulsive Therapy / Q000191:economics; D003362:Cost-Benefit Analysis; D003511:Cyclohexanols / Q000191:economics* / Q000627:therapeutic use; D003663:Decision Trees; D003866:Depressive Disorder / Q000188:drug therapy* / Q000191:economics / Q000453:epidemiology / Q000628:therapy; D003906:Developing Countries; D016527:Drug Costs; D005260:Female; D005473:Fluoxetine / Q000191:economics* / Q000627:therapeutic use; D005102:Health Expenditures / Q000706:statistics & numerical data; D006760:Hospitalization / Q000191:economics / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008962:Models, Theoretical; D009010:Monte Carlo Method; D009313:National Health Programs / Q000191:economics; D009819:Office Visits / Q000191:economics; D011613:Psychotherapy / Q000191:economics; D000069470:Venlafaxine Hydrochloride
D000928:Antidepressive Agents; D003511:Cyclohexanols; D005473:Fluoxetine; D000639:Amitriptyline; D000069470:Venlafaxine Hydrochloride