Author’s Response

We thank the readers for their letter. We wish to state that we had mentioned "opioid [tiab]" in the search title that is likely to capture all the drugs under the category. Both the articles suggested by the readers have 'opioid' in their title and so should have featured in the database search. For reasons not known, these articles did not appear in the search list. Even a fresh literature search with the search strategy used in the study failed to pick up these studies. We agree that the search strategy could have been more sensitive with the addition of 'Naldemedine'.

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