Hiroko Kotajima-Murakami1,2, Ayumi Takano1,3, Yasukazu Ogai4, Shotaro Tsukamoto2, Maki Murakami5, Daisuke Funada5, Yuko Tanibuchi6, Hisateru Tachimori7, Kazushi Maruo8, Tsuyoshi Sasaki9, Toshihiko Matsumoto1, Kazutaka Ikeda1,2. 1. Department of Drug Dependence Research, National Institute of Mental Health, National Center of Neurology and Psychiatry, Tokyo, Japan. 2. Addictive Substance Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan. 3. Unit of Public Health and Preventive Medicine, School of Medicine, Yokohama City University, Yokohama-shi, Japan. 4. Social Psychiatry and Mental Health, Faculty of Medicine, University of Tsukuba, Tsukuba-shi, Ibaraki, Japan. 5. Department of Psychiatry, National Center Hospital, National Center of Neurology and Psychiatry, Kodaira-shi, Tokyo, Japan. 6. Department of Psychiatry, Chiba Hospital, Funabashi-shi, Chiba, Japan. 7. Department of Clinical Research Promotion, Translational Medical Center, National Center of Neurology and Psychiatry, Kodaira-shi, Tokyo, Japan. 8. Department of Biostatistics, Faculty of Medicine, University of Tsukuba, Tsukuba-shi, Ibaraki, Japan. 9. Department of Child Psychiatry, Chiba-University Hospital, Chuo-ku, Chiba, Japan.
Abstract
AIMS: Pharmacotherapy for methamphetamine dependence has not yet been developed in Japan or elsewhere in the world. Ifenprodil is a blocker of G protein-activated inwardly rectifying potassium channels that play a key role in the mechanism of action of addictive substances. Our aim is to examine the safety, efficacy, and outcomes of ifenprodil for the treatment of methamphetamine dependence in a randomized, double-blind, placebo-controlled trial. METHODS: The recruitment of outpatients with methamphetamine dependence began in January 2018. The patients will be randomized into three arms: placebo, 60 mg/d ifenprodil, or 120 mg/d ifenprodil. Placebo or ifenprodil will be taken for 84 days. We will use Cerocral fine granule 4%® (ifenprodil tartrate). Follow-up assessments will be conducted for 84 d after the drug administration period. All of the patients will be assessed by self-administered questionnaires and urine tests. The primary outcome will be the presence or absence of methamphetamine use during the 84-day administration period in the 120 mg/d ifenprodil and placebo groups. Secondary outcomes will include the number of days and percentage of days of abstinence from methamphetamine use, positive urine for methamphetamine, relapse risk, and drug craving. DISCUSSION: This study is the first clinical trial of ifenprodil treatment for methamphetamine dependence and is designed as an intervention test with off-label drug use. The present study is expected to provide evidence of the effects of ifenprodil treatment on methamphetamine dependence. TRIAL REGISTRY: This trial was registered in the UMIN clinical trial registry (UMIN000030849; date of registration: January 17, 2018).
RCT Entities:
AIMS: Pharmacotherapy for methamphetamine dependence has not yet been developed in Japan or elsewhere in the world. Ifenprodil is a blocker of G protein-activated inwardly rectifying potassium channels that play a key role in the mechanism of action of addictive substances. Our aim is to examine the safety, efficacy, and outcomes of ifenprodil for the treatment of methamphetamine dependence in a randomized, double-blind, placebo-controlled trial. METHODS: The recruitment of outpatients with methamphetamine dependence began in January 2018. The patients will be randomized into three arms: placebo, 60 mg/d ifenprodil, or 120 mg/d ifenprodil. Placebo or ifenprodil will be taken for 84 days. We will use Cerocral fine granule 4%® (ifenprodil tartrate). Follow-up assessments will be conducted for 84 d after the drug administration period. All of the patients will be assessed by self-administered questionnaires and urine tests. The primary outcome will be the presence or absence of methamphetamine use during the 84-day administration period in the 120 mg/d ifenprodil and placebo groups. Secondary outcomes will include the number of days and percentage of days of abstinence from methamphetamine use, positive urine for methamphetamine, relapse risk, and drug craving. DISCUSSION: This study is the first clinical trial of ifenprodil treatment for methamphetamine dependence and is designed as an intervention test with off-label drug use. The present study is expected to provide evidence of the effects of ifenprodil treatment on methamphetamine dependence. TRIAL REGISTRY: This trial was registered in the UMIN clinical trial registry (UMIN000030849; date of registration: January 17, 2018).