IS CARDIOVASCULAR DISEASE A RISK FACTOR IN THE DEVELOPMENT OF AXONAL POLYNEUROPATHY?

Objectives: To determine if cardiovascular disease may be a risk factor in the development of chronic idiopathic axonal polyneuropathy (CIAP). Methods: In this incidence case-control study, the prevalence of cardiovascular disease and risk factors in 97 patients with CIAP (mean age 67.5 (SD 7.9) years) and the prevalence of neuropathic features in 97 patients with peripheral arterial disease (PAD) (mean age 67.1 (SD 7.3) years) were investigated. The results were compared with those for 96 age and sex matched controls without diagnosed PAD or polyneuropathy (mean age 67.5 (SD 9.1) years). In a randomly chosen subgroup of 23. patients with CIAP, 42 patients with PAD, and 48 controls, an electrodiagnostic investigation was performed. Results: Patients with CIAP more often had manifest cardiovascular disease and cardiovascular risk factors than controls (stroke 18% v 6% of patients, odds ratio (OR) 3.2 (95% confidence interval (0) 1.8 to 5.9); heart disease 29% v 15%, OR 2.4 (95% Cl 1.2 to 4.9); family history of cardiovascular disease 42% v 21%, OR 2.8 (95% Cl (1.5 to 5.2); hypertension 56% v 39%, OR 2.0 (95% Cl 1.1 to I I 3.6); hypercholesterolaemia 46% v 21%, OR 3.3 (95% Cl 1.5 to 7.3); current smoking 38% v 23%, OR 2.1 (95% Cl I. I to 3.9)). The prevalence of cardiovascular disease and cardiovascular risk factors was lower than in patients with PAD. Patients with PAD more often had polyneuropathy than controls (15% v 5%, OR 3.3 (95% Cl 1.1 to 10.0)). There was a trend towards lower nerve conduction velocities and lower amplitudes on electrodiagnostic investigation compared with controls. Conclusion: This study shows that cardiovascular disease and CIAP often coexist, and therefore cardiovascular disease may be a cofactor in the development of CIAP.     

Peak Plasma Concentrations After Oral Morphine: A Systematic Review

We performed a systematic review of 69 studies with information on 2146 subjects (454 patients and 1692 healthy volunteers) to examine the maximum plasma concentration (C_max) and the time taken to reach maximum concentration (T_max) for different oral morphine formulations, and to clarify factors contributing to variability. Data from healthy volunteers reflected that seen for patients but was less variable. There was minimal difference between single and multiple doses, suggesting no accumulation of morphine. For immediate-release morphine there was no difference in either dose-corrected C_max or T_max between solution and tablets, or between different salts. For controlled-release formulations, little difference was observed between brands. Only for once-daily formulations was there any difference in absorption between fed and fasted, with a T_max for fed subjects considerably longer than for fasted. There was no evidence for any difference between values obtained by radioimmunoassay (RIA) or high-performance liquid chromatography (HPLC).