You are here

Letter to the Editor

Correcting Naldemedine (Symproic) Product Summary

Marc Cataldo PharmD

To the Editor:

As the marketer and distributor of naldemedine (Symproic®) tablets, Purdue Pharma L.P. strives to ensure that the information about Symproic in published resources is accurate.

The article published in the August 2017 issue of P&T entitled “Pharmaceutical Approval Update” by Michele B. Kaufman, PharmD, BCGP, RPh, includes a review of naldemedine (Symproic). 1 The following information in this article requires further clarification and corrections:

  • In the section on Uniqueness of Drug, you state that naldemedine is the second orally available opioid antagonist for treating opioid-induced constipation (OIC).

    Symproic is the third orally available opioid antagonist for treating OIC, as naldemedine approval followed naloxegol and methylnaltrexone.

  • In the same section on Uniqueness of Drug, you state that naldemedine is the first oral opioid antagonist issued as a Schedule II (CII) controlled substance.

    Symproic was approved as a CII controlled substance because it is structurally related to naltrexone. Shionogi, Inc. (the new drug application holder), has submitted a petition for the descheduling of Symproic, or removal of the controlled substance classification, to the U.S. Drug Enforcement Administration, which is currently under review at the time of this communication. The proposed rule has been posted in the Federal Register as of July 12, 2017,2 and descheduling is expected in the near future. Symproic is not yet available and the product will be distributed only after descheduling has occurred.

  • In the section on Commentary, you describe the clinical trial efficacy endpoints for which naldemedine demonstrated improvements from placebo in the weekly frequency of spontaneous bowel movement (SBM), complete SBMs, and frequency of straining associated with SBMs from baseline to the last two weeks of the 12-week treatment period.

    Omitted are two endpoints of the Symproic clinical trials, one of which is the primary efficacy endpoint. The efficacy of Symproic was assessed using a responder analysis as the primary endpoint. A responder was defined as a patient who had at least three SBMs per week and a change from baseline of at least one SBM per week for at least nine out of the 12 weeks and three out of the last four weeks. The clinical trials demonstrated significantly higher responder rates with Symproic compared with placebo. Additionally, Symproic increased the mean frequency of SBMs per week from baseline to week 1 of the treatment period.

  • It is important that the published product summary is accurate and consistent with the Symproic full prescribing information3 and that readers are aware that Symproic will be distributed only after descheduling has occurred.

    Thank you for your consideration and attention to this matter.


    1. Kaufman MB. Pharmaceutical approval update. P T 2017;42;(8):502–504.
    2. Drug Enforcement Administration. Schedules of controlled substances: removal of naldemedine from control. Fed Regist 2017;82;(132):32153–32157. Available at: Accessed September 7, 2017
    3. Symproic (naldemedine) prescribing information Florham Park, New Jersey: Shionogi, Inc. Available at: Accessed September 7, 2017