Trends in opioid utilization in Hungary, 2006-2020: A nationwide retrospective study with multiple metrics.

Background: Opioid use is well documented in several countries: some countries struggle with overuse, whereas others have almost no access to opioids. For Europe, limited data are available. This study analysed Hungarian opioid utilization in ambulatory care between 2006 and 2020.

Dose-independent antinociceptive interaction of endogenous ligands at the spinal level.

Adenosine, agmatine and kynurenic acid are endogenous ligands acting on different (e.g. adenosine, NMDA, alpha(2)-adrenergic and imidazoline) receptors with a potential role in nociception at the spinal level.

The significance of intrathecal catheter location in rats.

Although chronic intrathecal catheterization is a widely used method in rats, few calibration experiments have been performed. In this study, we investigated the correlation between the side position of the catheter tip and the side differences observed in the motor and sensory disturbances after intrathecal administration of lidocaine to a large number of rats. The existence of a sensory block was determined by the paw withdrawal test.

The antinociceptive effect of intrathecal kynurenic acid and its interaction with endomorphin-1 in rats.

Kynurenic acid as an endogenous ligand antagonizes all types of ionotropic glutamate receptors, with preferential affinity for the glycine-binding site of the N-methyl-D-aspartate (NMDA) receptor. The purpose of the present study was to investigate the antinociceptive potency of continuously administered kynurenic acid on carrageenan-induced thermal hyperalgesia by means of a paw withdrawal test in awake rats. The possible interaction between kynurenic acid and the endogenous mu-opioid receptor agonist peptide, endomorphin-1, was examined in the same set-up.

Antinociceptive effect of continuous intrathecal administration of endomorphin-1.

Endomorphin-1 is a novel endogenous opioid peptide with high affinity and selectivity for the mu-opioid receptor. Earlier results have shown that it causes antinociception in different pain tests, but its effect is short-lasting. The purpose of the present study was to investigate the antinociceptive potency of continuously administered endomorphin-1 on carrageenan-induced thermal hyperalgesia by means of a paw withdrawal test in awake rats.