Urinary outflow obstruction

It is indicated in mild to moderate, hypertension, treatment of both urinary outflow obstruction, obstructive and irritative symptoms associated with BPH. 

Drug therapy may also cause renal insufficiency due to lower urinary tract obstruction. Ureteral obstruction can be caused by calculi or retroperitoneal fibrosis. Bladder dysfunction with urinary outflow obstruction can result, particularly in males with prostatic hypertrophy, from anticholinergic drugs including tricyclic antidepressants and disopyramide. Bladder outlet and ureteral obstruction may result from bladder fibrosis following hemorrhagic cystitis with cyclophosphamide or ifosfamide therapy. Concurrent treatment with mesna can prevent cystitis and this complication. 

The more severe cases of proximal hypospadias often show a narrowing of the urethra with signs of urinary outflow obstruction and are commonly associated with cloacal anomalies and female pseudohermaphroditism (Knight et al.l995). 

Postrenal ARF is due to obstruction of urinary outflow. Causes include benign prostatic hypertrophy, pelvic tumors, and precipitation of renal calculi.7 Rapid resolution of postrenal ARF without structural damage to the kidney can occur if the underlying obstruction is corrected. Postrenal ARF accounts for less than 10% of cases of ARF.6... 

Urinary retention Administer ER tablets with caution to patients with clinically significant bladder outflow obstruction because of the risk of urinary retention. Renal/Hepatic function impairment Use ER tablets with caution in patients with hepatic or renal impairment. 

Placebo-controlled urodynamic studies in men with BPH have unequivocally demonstrated that finasteride produces objective improvement in bladder oudet obstruction (Tammela and Kontturi, 1993 Kirby et al., 1992 Abrams et al., 1999 Schaffer et al., 1999). Singlecenter studies using detrusor pressure to measure outflow obstruction demonstrated that the majority of finasteride-treated patients were shifted out of the obstructed range as compared with placebo patients over a 3- to 6-month study period (Tammela and Kontturi, 1993 Kirby et al., 1992). Similar results were reported in a 1-year multicenter study in men with BPH (Abrams et al., 1999). Moreover, this study demonstrated that the magnitude of the improvement in bladder oudet obstruction and maximal urinary flow rate with finasteride over placebo increases with increasing prostate volume. Long-term (1-year), open-label follow-up evaluation for this study demonstrated further reductions in bladder oudet obstruction with chronic finasteride therapy (Schaffer etal, 1999). 

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