Dose-related effect of moxisylyte on maximal urethral closing pressure in patients with spinal cord injuries

Dysfunction of lower urinary tract in patients with spinal cord injury

Over the past 50 years, the mortality for urorenal cause in patients with spinal cord injuries (SCI) has decreased from over 75% to 2.3%, as a result of dramatic improvements in the diagnosis and management of lower urinary tract dysfunction (LUTD). The aims of this chapter are to assess the physiopathology of upper and lower motor neuron lesion on bladder and sphincter function after SCI, to give an overview of required clinical and instrumental examination and to discuss treatment modalities. Videourodynamic examination plays a key role in the assessment and follow-up of LUTD in SCI patients, in conjunction with neurophysiological and radiological examinations. The cornerstone of bladder management in SCI is clean intermittent self-catheterization, but often other treatments are needed to achieve full continence, to reduce infections and stone formation, to protect the upper urinary tract from excessive bladder pressure, and to prevent chronic renal failure. Treatments may be pharmacologic (i.e., anticholinergic drugs and botulinum toxin) or surgical (by enterocystoplasty or urinary diversion). In selected cases, neuromodulation and sacral root stimulation can be used to reduce detrusor overactivity and empty the bladder. Management of LUTD in SCI patients requires a deep knowledge of spinal cord medicine and functioning of patients with neurologic disability.

Moxisylyte: a review of its pharmacodynamic and pharmacokinetic properties, and its therapeutic use in impotence

Moxisylyte is a competitive noradrenaline antagonist, acting preferentially on post-synaptic alpha-1 adrenoceptors. It was introduced more than thirty years ago for the treatment of cerebro-vascular disorders and shown more recently effective in the urological field due to its ability to modulate the urethral pressure. Renewal of interest in this drug has been observed in recent years since the demonstration of the possibilities of vasoactive drugs in evaluation and treatment of erectile dysfunctions. Moxisylyte is a prodrug, rapidly transformed into an active metabolite in plasma (Deacetylmoxisylyte or DAM). Elimination of the active metabolite occurs by N-demethylation, sulpho- and glucuroconjugation. The N-demethylated metabolite is sulphoconjugated only. Urine is the main route of excretion. The metabolites of moxisylyte can be determined in biological fluids by various methods using high-performance liquid chromatography. Their pharmacokinetics is dependent on the route of administration. By the oral route, the concentrations of the active metabolite are low, and the glucuroconide of DAM predominates over the sulphates. After intravenous and intracavernous injection, the active metabolite is proportionally higher, the two sulphates are equivalent and in larger amounts than the glucuronide. In the treatment of impotence, intracavernous injection of moxisylyte at 10, 20 or 30 mg can induce an erection adequate for intercourse in most of the patients. Compared to inducing agents such as papaverine and prostaglandin E1, moxisylyte must be considered as a facilitator of male erection, its interest lying in the low rate of adverse effects, either general or local.

Effect of intravenous alfuzosin on urethral pressure in patients with neurogenic bladder dysfunction. DORALI Study Group

In order to assess the ability of a single intravenous (i.v.) injection of alfuzosin, a selective alpha-1 blocker, in reducing high urethral tone in patients with symptomatic neurogenic bladder dysfunction (NBD), 163 patients (mean maximal urethral pressure [MUP] 108 +/- 46 cm H2O) were enrolled in a double-blind, placebo-controlled, parallel-group trial and were randomly allocated to receive 0.5 mg (n = 45), 1 mg (n = 41), 2 mg (n = 39) alfuzosin or placebo (n = 38). The decrease in MUP was dose-dependent and statistically significant (P < or = 0.05) for 1 and 2 mg alfuzosin (respectively, 43 +/- 28 cm H2O and 46 +/- 27 cm H2O decreases vs. baseline) in comparison with placebo (23 +/- 30 cm H2O). The 2 mg dose level was the most effective leading to a > or = 30 or 50% decrease in MUP in, respectively, 69 and 44% of patients. The safety of all three alfuzosin dose levels was satisfactory and comparable to placebo. I.v. alfuzosin induces, in a dose-related manner, a clinically significant decrease in urethral pressure in patients with NBD and high urethral tone, and may be safely used as a pharmacological test as part of an urodynamic investigation.