- 著者
- Takeo Yasu Kenji Momo Shunsuke Kobayashi Seiichirou Kuroda Arinobu Tojo
- 出版者
- The Pharmaceutical Society of Japan
- 雑誌
- Biological and Pharmaceutical Bulletin (ISSN:09186158)
- 巻号頁・発行日
- pp.b17-00806, (Released:2017-12-06)
- 参考文献数
- 16
- 被引用文献数
- 16
Ponatinib, a novel tyrosine kinase inhibitor marketed in 2016, is a key drug used for treating chronic myeloid leukemia and Philadelphia chromosome-positive acute lymphoblastic leukemia. This study aimed to develop a simple method for determining plasma ponatinib concentration. The analysis required extraction of a 400-μL sample of plasma and precipitation of proteins using an Oasis HLB cartridge. Ponatinib and bosutinib, which is used as an internal standard, were separated by HPLC using a mobile phase of acetonitrile: 0.037 mol/L KH2PO4 (pH 4.5) (39:61, v/v) on a Capcell Pack C18 MG II (250 mm × 4.6 mm) monitored at 250 nm, with a flow rate of 1.0 mL/min. This assay method was then used for determining plasma ponatinib concentration in a 42-year-old man treated with ponatinib at 15 mg/day. The calibration curve was found to be linear for the plasma concentration range of 5–250 ng/mL with a regression coefficient (r2) of 0.9999. The coefficients of intra-day and inter-day validation under these concentrations were 2.1–6.0% and 4.5–8.0%, respectively. The assay accuracy was -1.5–9.0%, and the recovery was greater than 86%. The plasma concentration of the patient at 2.5 and 3 h after 15 mg ponatinib administration was 43.6 ng/mL and 49.3 ng/mL, respectively. This method of HPLC equipped with UV detection for determining plasma ponatinib concentration has several advantages, such as simplicity and applicability to routine therapeutic drug monitoring at hospital laboratories.
- 著者
- Takamichi Kanbayashi Shunsuke Kobayashi Yuki Hatanaka Jun Shimizu Masahiro Sonoo
- 出版者
- The Japanese Society of Internal Medicine
- 雑誌
- Internal Medicine (ISSN:09182918)
- 巻号頁・発行日
- vol.62, no.22, pp.3397-3400, 2023-11-15 (Released:2023-11-15)
- 参考文献数
- 14
Grip myotonia can be a clue for the diagnosis of myotonic disorders. However, several clinical conditions cause delayed finger opening mimicking grip myotonia. We herein report a 44-year-old man with idiopathic inflammatory myopathy who presented with delayed finger opening resembling grip myotonia. The delayed finger opening differed from grip myotonia given the absence of the warm-up phenomenon and percussion myotonia, relative sparing of the thumb extension, and pronounced weakness of the extensor digitorum. Focusing on the extension of the thumb and other fingers may aid in the differentiation between delayed finger opening and true grip myotonia.