Cost-effectiveness of tamsulosin, doxazosin, and terazosin in the treatment of benign prostatic hyperplasia.
OBJECTIVE
To evaluate the cost-effectiveness of tamsulosin, doxazosin, or terazosin as initial treatments for moderate benign prostatic hyperplasia (BPH) over a 3-year time horizon from a health-system-payer perspective.


METHODS
A decision-analytic model is used to project the course of treatment at 6-month intervals over 3 years following initiation of therapy with tamsulosin, doxazosin, or terazosin. Treatment failure is defined as failure to attain and maintain a 25% improvement in the American Urological Association (AUA) symptom score from baseline. In the model, finasteride is added for patients who fail on their initial therapy and, in the event of finasteride treatment failure, patients progress to transurethral resection of the prostate (TURP) and, if needed, a second TURP. The ranges of values for treatment failure rates and clinical event cost parameters used in the decision model are derived from the literature. Only direct medical costs related to BPH and its treatment are included. Since 2 comparators are available generically (doxazosin and terazosin) drug acquisition costs are defined by the list prices at Drugstore.com. All costs are discounted by 3% per year. Effectiveness is measured as successful medical treatment without surgery over 3 years.


RESULTS
For base-case model parameters, discounted BPH-related total direct medical costs over 3 years are 4084 dollars, 4323 dollars, and 4695 dollars for generic terazosin, generic doxazosin, and tamsulosin, respectively. The model estimates a medical treatment success rate (no TURP) at 3 years of 72.3% for tamsulosin, compared with 68.2% for both terazosin and doxazosin. The incremental cost for tamsulosin versus terazosin is 610 dollars over 3 years, which yields an incremental cost-effectiveness ratio of 14,609 dollars per success. Generic doxazosin is dominated (higher cost but equal effectiveness compared with terazosin). Higher rates of twice-daily (or 2 units per day) dosing are associated with higher incremental cost-effectiveness ratios. The decision-model results also are sensitive to the estimated costs of TURP and hypotensive adverse events.


CONCLUSIONS
As an initial medical therapy for moderate BPH, tamsulosin is more effective than generic terazosin or doxazosin, with an incremental cost of about 203 dollars per year (or about 17 dollars per month) over 3 years.
Ohsfeldt
Robert L
RL
Department of Health Management and Policy, College of Public Health, University of Iowa, Iowa City, Iowa 52242, USA. robert-ohsfeldt@uiowa.edu
Kreder
Karl J
KJ
Klein
Robert W
RW
Chrischilles
Elizabeth A
EA
D000317:Adrenergic alpha-Antagonists / Q000191:economics / Q000627:therapeutic use*; D003362:Cost-Benefit Analysis; D003661:Decision Support Techniques; D017292:Doxazosin / Q000191:economics / Q000627:therapeutic use*; D017850:Economics, Pharmaceutical; D004791:Enzyme Inhibitors / Q000627:therapeutic use; D018120:Finasteride / Q000627:therapeutic use*; D017048:Health Care Costs; D006801:Humans; D008297:Male; D011224:Prazosin / Q000031:analogs & derivatives* / Q000191:economics / Q000627:therapeutic use*; D011470:Prostatic Hyperplasia / Q000188:drug therapy* / Q000191:economics / Q000601:surgery; D013449:Sulfonamides / Q000191:economics / Q000627:therapeutic use*; D000077409:Tamsulosin; D020728:Transurethral Resection of Prostate; D016896:Treatment Outcome
D000317:Adrenergic alpha-Antagonists; D004791:Enzyme Inhibitors; D013449:Sulfonamides; D018120:Finasteride; C041226:Terazosin; D000077409:Tamsulosin; D017292:Doxazosin; D011224:Prazosin