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Pupillary Response as Assessment of Effective Seizure Induction by Electroconvulsive Therapy
Published on: April 11, 2019
Pupillometry in healthy volunteers as a biomarker of tramadol efficacy
O Matouskova1, O Slanar, L Chytil
1Clinical Pharmacology Unit, Institute of Pharmacology, 1st Faculty of Medicine, Charles University, Prague, Czech Republic.
What Is Known And Objective:
The opioid effect of tramadol, which can be detected by pupillary response, is predominantly mediated by the O-demethylated metabolite, formed via CYP2D6. This study was designed to evaluate the effects of tramadol using different parameters of pupillometry as biomarkers.
Methods:
Sixty-nine healthy volunteers received tramadol hydrochloride drops orally at a dose of 0·7 mg/kg. Pre-dose and 2-h post-dose pupillometric measurements were performed. The polymorphism of CYP2D6 was analysed.
Results And Discussion:
Large interindividual variability was observed in the tramadol-induced pupillary reaction. Miosis was induced in 69·6% and mydriasis in 30·4% of the subjects. The pupillary response differed in relation to the CYP2D6 genotype. A maximal difference in initial pupil diameter of 0·81 mm was found in extensive metabolizers. There were significant effects observed on the pupillary light reflex parameters with tramadol administration (P < 0·05) except for the reflex amplitude and constriction velocity.
What Is New And Conclusion:
The pharmacodynamic effects of tramadol were easily detected using both static and dynamic pupil parameters. The pharmacodynamic profiles were markedly influenced by the CYP2D6 phenotype.
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