ABSTRACT
BACKGROUND/OBJECTIVES: Clinical responses to naldemedine vary between individuals with advanced cancer. This is a prospective, single-center, observational study aimed to evaluate the influence of genetic polymorphisms and cachexia status on plasma naldemedine and clinical responses. METHODS: Forty-eight patients being treated with naldemedine for opioid-induced constipation under treatment of cancer pain were enrolled. Plasma naldemedine concentrations were determined on the fourth day or later after administration of naldemedine, and the associations with genotypes, cachexia status, and clinical responses were assessed. RESULTS: Cancer patients exhibited a large variation in the plasma naldemedine concentrations, and it was correlated with serum total protein level. Patients who were homozygous CYP3A5*3 had a higher plasma concentration of naldemedine than those with the *1 allele. ABCB1 genotypes tested in this study were not associated with plasma naldemedine. A negative correlation was observed between the plasma naldemedine concentration and 4ß-hydroxycholesterol level. The plasma naldemedine concentration was lower in patients with refractory cachexia than in those with precachexia and cachexia. While serum levels of interleukin-6 (IL-6) and acute-phase proteins were higher in patients with refractory cachexia, they were not associated with plasma naldemedine. A higher plasma concentration of naldemedine, CYP3A5*3/*3, and an earlier naldemedine administration after starting opioid analgesics were related to improvement of bowel movements. CONCLUSION: Plasma naldemedine increased under deficient activity of CYP3A5 in cancer patients. Cachectic patients with a higher serum IL-6 had a lower plasma naldemedine. Plasma naldemedine, related to CYP3A5 genotype, and the initiation timing of naldemedine were associated with improved bowel movements.
Subject(s)
Analgesics, Opioid , Cachexia , Cancer Pain , Cytochrome P-450 CYP3A , Naltrexone , Polymorphism, Genetic , Humans , Male , Female , Cachexia/genetics , Cachexia/drug therapy , Cachexia/etiology , Middle Aged , Analgesics, Opioid/pharmacokinetics , Analgesics, Opioid/adverse effects , Analgesics, Opioid/administration & dosage , Naltrexone/analogs & derivatives , Naltrexone/pharmacokinetics , Naltrexone/therapeutic use , Naltrexone/adverse effects , Prospective Studies , Aged , Cytochrome P-450 CYP3A/genetics , Cancer Pain/drug therapy , Cancer Pain/genetics , Neoplasms/drug therapy , Neoplasms/genetics , Neoplasms/complications , Genotype , ATP Binding Cassette Transporter, Subfamily B/genetics , Adult , Opioid-Induced Constipation/genetics , Opioid-Induced Constipation/drug therapy , Defecation/drug effectsABSTRACT
BACKGROUND: Long-term use of itraconazole (ITZ) is associated with a risk of inducing hepatotoxicity. This study aimed to evaluate the associations of plasma concentrations of ITZ and its hydroxylated metabolite (OH-ITZ) with endogenous markers of hepatic function. METHODS: Thirty six patients treated with oral ITZ solution for prophylaxis of deep mycosis were enrolled. Plasma concentrations of ITZ and OH-ITZ were determined on the 14th day or later after administration of ITZ. Their associations with endogenous marker levels of hepatic function including plasma coproporphyrin (CP)-I and OATP1B1 genotypes were assessed. RESULTS: The serum level of total bilirubin (T-Bil) was moderately correlated with the plasma concentration of total ITZ (tITZ) and OH-ITZ (tOH-ITZ). T-Bil elevation above 0.3 mg/dL was observed in 19% of patients, although statistically significant difference was not identified. The plasma concentration of tITZ had no correlation with other endogenous markers levels including AST, ALT, albumin, and plasma CP-I. The serum AST and plasma CP-I levels were correlated with the plasma concentration of free OH-ITZ (fOH-ITZ). T-Bil and plasma CP-I, a marker of OATP1B1 activity, were not correlated with each other, and neither was associated with the OATP1B1 genotypes. CONCLUSIONS: Plasma ITZ and OH-ITZ had a positive association with T-Bil. The patients with a higher fOH-ITZ level had lower OATP1B1 activity on the basis of plasma CP-I level. ITZ and OH-ITZ have the potential to slightly increase endogenous marker levels of hepatic function, although most likely by different mechanisms.
