Search PubMed⌕ Search

Biomedical subjects

Patrick J Potter

Publications and source records attributed to Patrick J Potter.

8 recordsLinked to original sources

Disordered control of the urinary bladder after human spinal cord injury: what are the problems?

Spinal cord injury has a profound impact on the storage and voiding functions of the urinary bladder. Loss of autonomic and somatic control mechanisms leads to hypo- or hyperactivity of the bladder wall and sphincters causing problems that range from incontinence to complete loss of the capacity to empty the bladder. This chapter outlines the types of bladder dysfunction that occur after spinal cord injury, their relative prevalence and current practices used to manage the problems. With all the interventions that are available, management of bladder function often still remains a compromise, as the medications and physical interventions available may stimulate or block components of the voiding reflex, but are often not fully restorative in this effort.

Humans↗

Anticoagulation.

Explore the source record for details and available documents.

Ambulatory Care Facilities↗

Pharmacokinetics and safety of multiple oral doses of sustained-release 4-aminopyridine (Fampridine-SR) in subjects with chronic, incomplete spinal cord injury.

OBJECTIVE: To examine the pharmacokinetics and safety of sustained-release 4-aminopyridine (Fampridine-SR), a potassium channel blocker, in subjects with chronic, incomplete spinal cord injury (SCI). DESIGN: Open-label. SETTING: Clinical research unit in Ontario. PARTICIPANTS: Sixteen neurologically stable subjects with chronic, incomplete SCI (American Spinal Injury Association Impairment Scale grade B, C, or D). INTERVENTION: Oral administration of Fampridine-SR (25, 30, 35, 40, 50, 60 mg twice daily, each for 1 wk). MAIN OUTCOME MEASURES: Steady-state pharmacokinetic parameters: maximum observed plasma concentration (Cmax), minimum observed plasma concentration (Cmin), average observed plasma concentration (Cav), area under the plasma concentration-time curve from 0 to 12 hours (AUC(0-12)), time to Cmax (tmax), plasma half-life (t(1/2)), apparent volume of distribution (Vd/F), and apparent total clearance (Cl/F). Safety assessments: physical examinations, vital sign measurements, clinical laboratory tests, electrocardiogram recordings, and adverse events. RESULTS: Mean steady-state Cmax, Cmin, Cav, and AUC(0-12) increased over the entire Fampridine-SR dosage range and were dosage dependent up to 50 mg twice daily. Fampridine-SR had a mean tmax of 2.2 to 3.0 hours and a mean t(1/2) of 5.7 to 6.9 hours. Mean Vd/F (415.4-528.0 L) and Cl/F (51.4-57.7 L/h) were independent of dosage, as were mean tmax and t(1/2) across dosages. Adverse events were mild or moderate and were not dosage related. During the entire study period (17 wk), dizziness was the most frequently reported adverse event, followed by urinary tract infection, paresthesia, ataxia, and insomnia. CONCLUSION: In subjects with chronic, incomplete SCI, Fampridine-SR was slowly absorbed and eliminated, which will allow Fampridine-SR to be administered in a convenient twice-daily manner. Fampridine-SR was well tolerated at dosages from 25 to 60 mg twice daily.

4-Aminopyridine↗

Neck pain.

Explore the source record for details and available documents.

Decompression, Surgical↗

Clinical and electrophysiologic correlates of quantitative sensory testing in patients with incomplete spinal cord injury.

OBJECTIVE: To determine the degree of association among indices of preserved sensation derived from quantitative sensory testing (QST), somatosensory evoked potentials (SEPs), and the clinical characteristics of patients with spinal cord injury (SCI). DESIGN: A controlled correlational study of diverse measures of preserved sensory function. SETTING: Regional SCI rehabilitation center in Ontario, Canada. PARTICIPANTS: Thirty-three patients with incomplete SCI and 14 able-bodied controls. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: QST measures of perceptual threshold for temperature and vibration, American Spinal Injury Association sensory scores (light touch, pinprick), and tibial nerve SEPs. RESULTS: There was a low degree of association (kappa) between QST results and sensory scores (|kappa|=.05-.44). QST measures yielded greater numbers of patients with SCI being classified as impaired, suggesting a greater sensitivity of QST to detect more subtle sensory deficits. QST measures of vibration threshold generally corresponded to the patients' SEP recordings. QST measures of modalities conveyed within the same tract were significantly (P<.05) correlated (|r|=.46-.84) in patients with SCI, but not in controls, whereas those modalities mediated by different pathways had lower and generally nonsignificant correlations (|r|=.05-.44) in both patients and controls. CONCLUSIONS: The low degree of association between QST measures and sensory scores is likely attributable to measurement limitations of both assessments, as well as various neuroanatomic and neuropathologic factors. QST provides more sensitive detection of preserved sensory function than does standard clinical examination in patients with incomplete SCI.

Adult↗

Pharmacokinetic studies of single and multiple oral doses of fampridine-SR (sustained-release 4-aminopyridine) in patients with chronic spinal cord injury.

Fampridine (4-aminopyridine) is a potassium channel blocking agent that restores conduction in demyelinated axons and improves neurologic function in patients with chronic spinal cord injury (SCI). Based on the pharmacokinetic profile of orally administered fampridine, multiple daily doses (4 or more) would need to be taken to sustain its therapeutic effects. Two studies were conducted to determine the pharmacokinetics and safety profile of an oral, sustained-release (SR) formulation of fampridine (fampridine-SR, 10-25 mg) administered as a single dose (n = 14) and twice daily for 1 week (n = 16) in patients with chronic, incomplete SCI. Mean plasma concentrations and area under the plasma concentration-time curve were proportional to the dose administered, whereas other pharmacokinetic parameters were independent of dose. Fampridine-SR was absorbed slowly (peak plasma concentration shortly after dosing, 2.6-3.7 hours) and eliminated (plasma half-life, 5.6-7.6 hours), and reached steady state after 4 days of twice-daily administration. Fampridine-SR was well tolerated, with only mild to moderate adverse events reported, and no serious adverse events. The extended plasma half-life of fampridine-SR allows convenient twice-daily dosing. Clinical trials designed to assess neurologic and functional improvement using fampridine-SR in patients with chronic SCI are currently underway.

4-Aminopyridine↗