Basic & clinical pharmacology & toxicology
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Basic Clin. Pharmacol. Toxicol. · Nov 2011
Randomized Controlled TrialIs electrical brain activity a reliable biomarker for opioid analgesia in the gut?
The effects of morphine on brain potentials after experimental gut pain have never been investigated. This study explored whether multi-channel-evoked brain potentials (EP) and corresponding dipole sources in the brain would reflect the effects of morphine on experimental oesophageal pain. In a crossover study, the effects of oral morphine (30 mg) or corresponding placebo on pain from electrical oesophageal stimulation were tested in 12 healthy male volunteers. ⋯ The length of the vector describing this shift correlated inversely with the magnitude of the subjective pain relief (r = -0.7; p = 0.02). With the potential of becoming a useful biomarker in analgesic trials, the localization of the dipole sources reflected the analgesic action of morphine after pain stimuli of the gut. Even though further evaluation of the method is necessary, it has the potential to be a valid objective biomarker for opioid analgesia.
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Basic Clin. Pharmacol. Toxicol. · Nov 2011
Randomized Controlled TrialA randomized, controlled trial validates a peripheral supra-additive antihyperalgesic effect of a paracetamol-ketorolac combination.
The combination of paracetamol with non-steroidal anti-inflammatory drugs (NSAIDs) is widely used; however, the nature and mechanism of their interaction are still debated. A double-blind, pharmacokinetic/pharmacodynamic, randomized, cross-over, placebo-controlled study was carried out in human healthy volunteers. The aim was to explore the existence of a positive interaction between paracetamol 1 g and ketorolac 20 mg administered intravenously on experimental pain models in human beings. ⋯ No pharmacokinetic interactions were observed. These results suggest a supra-additive pharmacodynamic interaction between paracetamol and ketorolac in an inflammatory pain model. The mechanism of this interaction could mainly rely on a peripheral contribution of paracetamol to the effect of NSAIDs.
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Basic Clin. Pharmacol. Toxicol. · Apr 2011
Randomized Controlled TrialPharmacokinetic/pharmacodynamic relationships of transdermal buprenorphine and fentanyl in experimental human pain models.
Pharmacokinetic/pharmacodynamic (PK/PD) modelling can be used to characterize the relationship between dose regimen of opioids, plasma concentration and effect of opioids, which in turn can lead to more rational treatment regimens of pain. The aim of this study was to investigate the concentration-effect relationship for transdermal buprenorphine and fentanyl in experimentally induced pain. Twenty-two healthy volunteers were randomized to receive transdermal patches with fentanyl (25 μg/hr, 72 hr), buprenorphine (20 μg/hr, 144 hr) or placebo. ⋯ Buprenorphine significantly attenuated bone-associated pain, heat pain, nerve growth factor-induced soreness and cold pressor pain. Fentanyl significantly attenuated cold pressor pain for the administered dose regimens. Although the PK/PD relationship for both drugs could be described with similar models, tissue-differentiated analgesic effects between buprenorphine and fentanyl was shown.
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Basic Clin. Pharmacol. Toxicol. · Nov 2010
Comparative StudyDoes Pregabalin (Lyrica(®) ) help patients reduce their use of benzodiazepines? A comparison with gabapentin using the Norwegian Prescription Database.
Pregabalin (Lyrica(®) ) may have an anxiolytic effect. It has also been reported that the use of this drug helps prevent excessive use of benzodiazepines. The aim of the present study was to examine if pregabalin reduced the intake of benzodiazepines. ⋯ Between 15% and 29% of the patients were able to stop using benzodiazepines after starting pregabalin or gabapentin treatment. Psychiatric patients who started pregabalin were able to reduce the amount of benzodiazepines used by 48%, compared to only 14% among starters of gabapentin. This study shows that some patients reduced their use of benzodiazepines substantially after starting pregabalin.
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Basic Clin. Pharmacol. Toxicol. · Sep 2010
Relationship between serum acetaminophen concentration and N-acetylcysteine-induced adverse drug reactions.
Intravenous N-acetylcysteine is usually regarded as a safe antidote. However, during the infusion of the loading dose, different types of adverse drug reactions (ADR) may occur. The objective of this study was to investigate the relation between the incidence of different types of ADR and serum acetaminophen concentration in patients presenting to the hospital with acetaminophen overdose. ⋯ However, there were no significant differences in serum acetaminophen concentrations between patients with and without the following ADR: gastrointestinal reactions (p = 0.77), respiratory reactions (p = 0.96), central nervous reactions (p = 0.82) and cardiovascular reactions (p = 0.37). In conclusion, low serum acetaminophen concentrations were associated with higher cutaneous anaphylactoid reactions. Such high serum acetaminophen concentrations may be protective against N-acetylcysteine-induced cutaneous ADR.