Cause:Bladder outlet obstruction, eg, BPH, uterine prolapse, constipation, -stimulant drugs, neuropathy (impaired sensory input to sacral micturation center); or diminished detrusor strength (flaccid due to lower motor neuron disease or meds such as anticholinergics, calcium channel blockers, smooth muscle relaxants)

Sx:Obstructive w diminished urinary stream, frequency; if neuropathic, will have no sensation of bladder fullness

Lab:Postvoid residuum >100 cc; cystometrics show no contractions w 400+ cc when due to diminished sensation

Rx:

Self-catheterization (Jags 1990;38:364)

Stool softeners for constipation

Rx prolapse or BPH

Increase detrusor strength w parasympathomimetics, bethanechol (Urecholine) 10+ mg po tid, or phenoxybenzamine (Dibenzyline) 10 mg po qd

Block sphincter constriction ( blockade) w doxazosin (Cardura) 2-8 mg po qd, prazosin (Minipress) 1-2 mg po tid, tamsulosin (Flomax) 0.4-0.8 mg po qd, or terazosin (Hytrin) 1 mg incr to 5-10 mg po qd-bid; all $30-50/d