Synergic interaction between ritodrine and magnesium sulfate on the occurrence of critical neonatal hyperkalemia: A Japanese nationwide retrospective cohort study
Authors: Yada Yukari , Ohkuchi Akihide , Otsuki Katsufumi , Goishi Keiji , Takahashi Mari , Yonemoto Naohiro , Saito Shigeru , Kusuda Satoshi ,   The Survey Group Studying the Effects of Tocolytic Agents on Neonatal Adverse Events in Japan Society of Perinatal and Neonatal Medicine, Ota Hajime , Kosugiyama Kiyotaka , Okuyama Kazuhiko , Mizushima Masato , Negishi Hideaki , Koshida Shinichi , Kasai Mayumi , Okabe Motonari , Sato Akira , Adachi Hiroyuki , Banzai Michio , Akaba Kazuhiro , Suzuki Rika , Ishibashi Naohisa , Watanabe Takashi , Kasuga Yoshio , Kameda Takashi , Fujiu Toru , Takagi Takeshi , Maruyama Kenichi , Higashino Masahiko , Naito Tomomi , Kamei Yoshimasa , Kunikata Tetsuya , Iitsuka Yoshinori , Otsuka Harumi , Yamamoto Yuka , Yamada Mie , Daigo Masaki , Hyodo Hironobu , Sato Ayumi , Kataoka Noriko , Yamanaka Satoko , Okahashi Aya , Kojima Yuki , Kabashima Shigenori , Nakamura Yoshie , Okuno Rina , Hirose Seiko , Sugahara Koichi , Okamoto Satsuki , Hara Sumiko , Shima Wakako , Suzuki Takeshi , Kagawa Hideyuki , Fujioka Kenichiro , Kurasaki Akiko , Miura Ayako , Hokuto Isamu , Arase Toru , Taguchi Nobuhiko , Sekiguchi Kazuki , Matsuo Tomoyo , Ohnuma Emi , Fujiwara Kana , Ogawa Miyuki , Uozumi Azusa , Yokomichi Noriyuki , Hirose Akane , Okuda Mika , Fukuyama Ayako , Ishimoto Hitoshi , Mitsuzuka Kanako , Kondo Shinya , Kitazawa Miyuki , Kikuchi Norihiko , Miyashita Yumiko , Tsutsumi Chiharu , Terada Shuhei , Ohki Shigeru , Kawamura Takakazu , Yasuda Masako , Soeno Yoshiki , Kurabayashi Takumi , Nagayama Yoshihisa , Yoneda Satoshi , Shiga Tomomi , Hayashi Seiji , Tsuda Hiroyuki , Oshiro Makoto , Ushida Takafumi , Mizutani Teruyuki , Asada Hideyuki , Miura Ryousuke , Tanaka Ryo , Kato Noriko , Sasaki Yuko , Yokoyama Takehiko , Hirooka Takako , Yamada Takaharu , Maruwaka Kaori , Nagara Syunsuke , Fukaya Satoko , Koroki Mari , Tanaka Taihei , Morikawa Shigehiko , Honda Shigeru , Sassa Haruki , Sahashi Takeshi , Torii Hiroko , Yasuo Tadahiro , Kuriyama Nozomi , Okada Juzo , Kano Moe , Oki Noriyoshi , Inagaki Mieko , Mizuno Yousuke , Fujisaka Masayo , Takatera Akihiro , Mure Takeo , Yoshii Katsuhiko , Furuichi Yasuko , Kanto Akiko , Fukui On , Hayashi Shusaku , Ono Hitomi , Fujikawa Eri , Someya Masayuki , Ikeda Makiko , Nakanishi Kentaro , Yamashita Akiko , Kawaguchi Haruna , Yamamoto Ryo , Sasahara Jun , Kanagawa Takeshi , Yamamoto Satoshi , Imanishi Yosuke , Yoshida Misuzu , Yano Eri , Murayama Ayumi , Morikawa Kazue , Tabata Natsuko , Araki Ryosuke , Iwasaki Eriko , Mochizuki Narutaka , Kobayashi Akiko , Takeda Akiko , Kobayashi Akiko , Hirose Masaya , Taguchi Nao , Sato Hiroshi , Oida Kenji , Sakai Rie , Imai Saeko , Shiro Reona , Okudate Minami , Matsuda Yoko , Nishida Yoshinobu , Toyofuku Aya , Hara Shigeto , Kurioka Hiroko , Mizunoe Tomoya , Eto Syouhei , Nobuzane Takahiro , Higuchi Kousyou , Miwa Terumi , Hasegawa Keiko , Matsubara Yuko , Ohta Masaaki , Watanabe Takafumi , Ohmaru-Nakanishi Takako , Kashinoura Kana , Goto Maki , Kanda Hiroshi , Tsukimori Kiyomi , Takahata Yasushi , Nomiyama Makoto , Takayanagi Toshimitsu , Yoshimura Syuichiro , Kotera Kouhei , Fukuda Hisanobu , Hiraki Hiroko , Nagata Noriko , Nakashima Kazuhisa , Miyoshi Junya , Obara Takafumi , Kai Kentaro , Furukawa Yuichi , Eto Satoshi , Oishi Tomoko , Nakashima Misaki , Yamauchi Aya , Kodama Yuki , Ohata Takako , Arakaki Haruka , Miyakoshi Kei , Hida Mariko 
Published: May 2020

Our aim was to evaluate the association between ritodrine and magnesium sulfate (MgSO4) and the occurrence of neonatal hyperkalemia or hypoglycemia among late preterm infants in a retrospective cohort study. We used a nationwide obstetrical database from 2014. A total of 4,622 live preterm infants born at 32–36 gestational weeks participated. Fourteen risk factors based on both clinical relevance and univariate analysis were adjusted in multivariable logistic regression analyses. Neonatal hyperkalemia and hypoglycemia occurred in 7.6% (284/3,732) and 32.4% (1,458/4,501), respectively. Occurrence of hyperkalemia was associated with concomitant usage of ritodrine and MgSO4 compared with no usage (adjusted odds ratio [aOR] 1.53, 95% confidence interval [CI] 1.09–2.15). Occurrence of hypoglycemia was associated with ritodrine alone (aOR 2.58 [CI 2.21–3.01]) and with concomitant usage of ritodrine and MgSO4 (aOR 2.59 [CI 2.13–3.15]), compared with no usage, and was associated with long-term usage (≥ 48 hours) of ritodrine and cessation directly before delivery. In conclusion, in late preterm infants, usage of ritodrine together with MgSO4 was associated with occurrence of critical neonatal hyperkalemia, and long-term usage of ritodrine and cessation directly before delivery were associated with neonatal hypoglycemia.