The chemical structures of morphine and its metabolites are closely related to the clinical effects of drugs (analgesia and side-effects) and to their capability to cross the Blood Brain Barrier (BBB). Morphine-6-glucuronide (M6G) and Morphine-3-glucuronide (M3G) are both highly hydrophilic, but only M6G can penetrate the BBB; accordingly, M6G is considered a more attractive analgesic than the parent drug and the M3G. Several hypotheses have been made to explain these differences. In this review we will discuss recent advances in the field, considering brain disposition of M6G, UDP-glucoronosyltransferases (UGT) involved in morphine metabolism, UGT interindividual variability and transport proteins.
19 May 2013 in European Journal of Clinical Pharmacology
We analyzed the use of isavuconazole (ISA) as treatment or prophylaxis for invasive fungal disease (IFD) in children with hemato-oncologic diseases. A multicentric retrospective analysis was performed among centers belonging to the Italian Association for Pediatric Hematology and Oncology (AIEOP). Pharmacokinetic (PK) monitoring was applied by a high-performance liquid chromatography-tandem mass spectrometry (HLPC-MS/MS) assay.
Cytochromes P450 are members of a superfamily of hemoproteins that catalyze a variety of oxidative reactions in the metabolism of endogenous and exogenous hydrophobic substrates. Fifty-eight cytochrome P450 (CYP) isoenzymes belonging to 18 families have been identified in human cells; the corresponding genes are highly polymorphic, and genetic variability underlies interindividual differences in drug response. The polymorphisms of CYP2D6 significantly affect the pharmacokinetics of about 50% of the drugs in clinical use, which are CYP2D6 substrates. The number of functional CYP2D6 alleles per genome determines the existence of four different phenotypes, i.e. poor, intermediate, extensive, and ultrarapid metabolizers. CYP2D6 genetic variants include copy number variations, single nucleotide substitutions, frameshift and insertion/deletion mutations. This review reports some of the different methodological approaches used to screen for CYP2D6 variants and focuses on methods that have improved variation detection, from conventional techniques to more recent microarray technology and high throughput DNA sequencing. In addition, this review reports some results on clinical relevance of CYP2D6 polymorphisms and provides examples of variability in drug response associated with interindividual phenotypic differences.
Systemic inflammation participates to the complex healing process occurring after major surgery, thus directly affecting the surgical outcome and patient recovery. Total plasma N-glycome might be an indicator of inflammation after major surgery, as well as an anti-inflammatory therapy response marker, since protein glycosylation plays an essential role in the inflammatory cascade. Therefore, we assessed the effects of surgery on the total plasma N-glycome and the association with self-administration of postoperative morphine in two cohorts of patients that underwent major abdominal surgery. We found that plasma N-glycome undergoes significant changes one day after surgery and intensifies one day later, thus indicating a systemic physiological response. In particular, we observed the increase of bisialylated biantennary glycan, A2G2S[3,6]2, 12 hours after surgery, which progressively increased until 48 postoperative hours. Most changes occurred 24 hours after surgery with the decrease of most core-fucosylated biantennary structures, as well as the increase in sialylated tetraantennary and FA3G3S[3,3,3]3 structures. Moreover, we observed a progressive increase of sialylated triantennary and tetraantennary structures two days after surgery, with a concomitant decrease of the structures containing bisectingN-acetylglucosamine along with bi- and trisialylated triantennary glycans. We did not find any statistically significant association between morphine consumption and plasma N-glycome.