Background: Contradictory results from clinical trials that examined the role of vitamin E in chronic disease could be a consequence of interindividu

Remifentanil has been suggested for its short duration of action to replace standard opioids for induction of general anaesthesia in caesarean section. While the stabilizing effect of remifentanil on maternal circulation has been confirmed, its effect on postnatal adaptation remains unclear, as currently published studies are not powered sufficiently to detect any clinical effect of remifentanil on the newborn. Using a double-blinded randomized design, a total of 151 parturients undergoing caesarean delivery under general anaesthesia were randomized into two groups – 76 patients received a bolus of remifentanil prior to induction, while 75 patients were assigned to the control group. Remifentanil 1 μg/kg was administered 30 seconds before the standard induction of general anaesthesia. The primary outcome measure was an assessment of neonatal adaptation using the Apgar score, while secondary outcomes included the need for respiratory support after delivery and differences in umbilical blood gas analysis (Astrup). The incidence of lower Apgar scores between 0 and 7 was significantly higher in the remifentanil group at one minute (25% vs. 9.3% of newborns, p = 0.017); whilst at five minutes and later no Apgar score differences were observed. There was no difference in the need for moderate (nasal CPAP) or intensive (intubation) respiratory support, but significantly more neonates in the remifentanil group required tactile stimulation for breathing support (21% vs. 7% of newborns, p = 0.017). There was no difference in the parameters from umbilical cord blood gas analysis between the groups. At a dose of 1 μg/kg, remifentanil prior to induction of general anaesthesia increases the risk of neonatal respiratory depression during first minutes after caesarean delivery but duration of clinical symptoms is short. ClinicalTrials.gov: NCT01550640 .

There exists a marked inter-individual variability of P-glycoprotein expression and activity, which can be of clinical importance due to the large number of drugs that are substrates for the transporter. Previously identified polymorphisms in the MDR1 gene belong to important factors causing this phenomenon. Our aim was to investigate the frequency of major functional SNPs of the MDR1 gene coding for P-glycoprotein in the Czech population. DNA was isolated from whole blood of 189 healthy, young and unrelated subjects (99 females and 90 males, aged from 23 to 28 years). The genotypes of polymorphic positions C3435T, G2677T/A, C1236T and T-76A were determined by PCR-RFLP. Observed allelic frequencies were 56.5%, 46.0%, 0.53%, 44.5% and 37.6% for the alleles 3435T, 2677T, 2677A, 1236T and -76A, respectively. We have found 64 subjects homozygous for 3435T, 42 for 2677T, 40 for 1236T and 31 for -76A alleles. The allelic distribution complies well with Hardy-Weinberg equilibrium. Allelic frequencies of functionally important MDR1 variants are in the Czech population similar to that of other Caucasian populations.

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. 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. 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. 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.