Relationship of opioid prescription sales and overdoses, North Carolina

BACKGROUND

In the United States, fatal drug overdoses have tripled since 1991. This escalation in deaths is believed to be driven primarily by prescription opioid medications. This investigation compared trends and patterns in sales of opioids, opioid drug overdoses treated in emergency departments (EDs), and unintentional overdose deaths in North Carolina (NC).

METHODS

Our ecological study compared rates of opioid sales, opioid related ED overdoses, and unintentional drug overdose deaths in NC. Annual sales data, provided by the Drug Enforcement Administration, for select opioids were converted into morphine equivalents and aggregated by zip code. These opioid drug sales rates were trended from 1997 to 2010. In addition, opioid sales were correlated and compared to opioid related ED visits, which came from a Centers for Disease Control and Prevention syndromic surveillance system, and unintentional overdose deaths, which came from NC Vital Statistics, from 2008 to 2010. Finally, spatial cluster analysis was performed and rates were mapped by zip code in 2010.

RESULTS

Opioid sales increased substantially from 1997 to 2010. From 2008 to 2010, the quarterly rates of opioid drug overdoses treated in EDs and opioid sales correlated (r=0.68, p=0.02). Specific regions of the state, particularly in the southern and western corners, had both high rates of prescription opioid sales and overdoses.

CONCLUSIONS

Temporal trends in sales of prescription opioids correlate with trends in opioid related ED visits. The spatial correlation of opioid sales with ED visit rates shows that opioid sales data may be a timely way to identify high-risk communities in the absence of timely ED data.

Magnetic motor-evoked potentials in epilepsy: effects of the disease and of anticonvulsant medication

Magnetic motor-evoked potentials were recorded in 53 patients with medically intractable, mainly temporal lobe epilepsy and compared with potentials of 110 healthy volunteers. The motor-evoked potentials were reevaluated in 16 of the 53 patients after substantial reduction of antiepileptic drug doses. The objective was to assess the effect of epilepsy and of anticonvulsant medication on the central motor system. In subjects receiving antiepileptic treatment, cortical threshold intensities were markedly elevated and peripheral latencies were prolonged. Cortical threshold intensities and peripheral latencies decreased to approach control values after anticonvulsant medication was reduced but were increased in patients treated with 2 or 3 anticonvulsant agents instead of 1. Additionally, high levels of interictal epileptiform activity and a high frequency of seizures significantly decreased the central motor conduction time and, in part, threshold intensities. The central motor conduction time was further diminished after reduction of anticonvulsant treatment and increased when several drugs were administered. The duration of epilepsy, the location of the epileptic focus, and the type of the epileptic seizure did not affect motor-evoked potentials. Conclusively, central motor pathways are endogenously facilitated by epileptiform activity even if clinical signs of their involvement are absent. Anticonvulsant medication exerts major reversible effects on magnetic motor-evoked potentials.

[On the mechanism of valve plane (author's transl)]

A detailed description of the functional sequence and mechanism of the valve plane movements is given as an extension of the studies on the functional morphology of cardiac movements. The valve plane mechanism is driven in the small, rapidly beating heart by the contraction of the external and internal spiral fibres of the myocardium which decreases the width of the chamber. The atrium is enlarged during systole by the descent of the valvular ring towards the apex. The auricular apendices must act as a compensation reservoir giving the atrial wall the necessary freedom of movement within the pericardial dome. Under these working conditions (hypovolaemia, decreased venous return pathophysiological consequences are discernible as subendocardial bleeding secondary to increased sliding movement of the inner layer of the myocardium against the middle layer. Chamber dilation as a consequence of endocardial fibrosis is explained as a result of progressive rigidity of endo-epicardial fixation. These structural changes progressively impair the systolic-diastolic changes in wall thickness.