In this review, optimization of individualized
analgesic therapy in
cancer-pain patients (1), pharmacoepidemiological studies using a hospital database (DB) (2), and other clinical and practical research studies (3) were summarized. (1) The aim of the
analgesic study was to evaluate individual factors in the effects of
pain-relief, and ADR of
analgesics from the viewpoints of clinical pharmacokinetics and pharmacodynamics.
Oxycodone,
fentanyl, and
gabapentin were used. For the dose escalation and ADR of
oxycodone, the plasma disposition of
noroxycodone regulated by
CYP3A5 polymorphisms and
cancer cachexia were found to be individual factors. The ADR and clinical response of
fentanyl were affected by polymorphisms of
CYP3A5 and ABCB1. In the pharmacokinetics of
gabapentin, concomitant
magnesium oxide reduced the intestinal absorption of
gabapentin. (2) The aim of the DB study was to demonstrate a pharmacoepidemiological advantage using a hospital DB of a million-scale for post-marketing safety management. We tried to detect
fluoroquinolone (FQ)-induced tendon disorders, because its risk ratio in Japan has not been clarified. The risk of a tendon disorder in FQ-prescribed patients was 0.082% (95%CI: 0.049-0.137%), and significantly higher than that in
cephalosporin-prescribed patients. The risk ratio in FQ-prescribed patients in relation to
cephalosporin-prescribed patients was 6.29 (95%CI: 2.27-17.46). (3) Individual variation of plasma exposure of free
linezolid and its ratio to minimum inhibitory concentration in
critically ill patients, as well as three other studies, were described. In conclusion, our achievement in accurately assessing these would contribute to medication safety and the appropriate use of medicines in clinical settings.