{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,27]],"date-time":"2026-02-27T05:06:20Z","timestamp":1772168780911,"version":"3.50.1"},"update-to":[{"DOI":"10.12688\/f1000research.122507.1","type":"new_version","label":"New version","source":"publisher","updated":{"date-parts":[[2024,9,16]],"date-time":"2024-09-16T00:00:00Z","timestamp":1726444800000}}],"reference-count":2,"publisher":"F1000 Research Ltd","license":[{"start":{"date-parts":[[2024,9,16]],"date-time":"2024-09-16T00:00:00Z","timestamp":1726444800000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["f1000research.com"],"crossmark-restriction":false},"short-container-title":["F1000Res"],"abstract":"<ns3:p>\n                    Reddy and Reddy (2014) discuss the optimal timing for lithium levels in patients taking once-daily extended-release lithium formulations. They argue for blood sampling 24 h after the previous dose rather than the standard 12 h. I interpret the data quite differently. The authors start with the assumption that the clinician wants a trough level. I disagree. What one wants is to be able to compare a patient\u2019s lithium level to the large body of published knowledge about lithium dosing. Almost all of that data comes from standard 12-h blood draws with plain (immediate-release) lithium carbonate or lithium citrate. So, the real question of interest is, with extended-release lithium formulations, at what time point does one draw the lithium level to compare most accurately with a standard 12-h blood draw with plain lithium carbonate? The answer is not obvious because extended-release formulations affect only the absorption and not the excretion of lithium. Their primary benefit is reducing the transient peak lithium serum concentration, not delaying the (already relatively slow) elimination of lithium. Emami and colleagues (2004) provide the needed data. First they show that 90% of the administered dose of a commercial extended-release formulation (Eskalith CR\n                    <ns3:sup>\u00ae<\/ns3:sup>\n                    ) is absorbed by 4 h after a dose, and ~100% is absorbed by 8 h (their Figure 2A). Second, they show that at 12 h after a dose, the blood levels for immediate and extended release formulations are essentially identical (their Figure 3).\u00a0 Thus 12 h after the previous dose is the ideal time for drawing blood levels for extended-release lithium tablets.\n                  <\/ns3:p>","DOI":"10.12688\/f1000research.122507.2","type":"journal-article","created":{"date-parts":[[2024,9,16]],"date-time":"2024-09-16T07:20:05Z","timestamp":1726471205000},"page":"779","update-policy":"https:\/\/doi.org\/10.12688\/f1000research.crossmark-policy","source":"Crossref","is-referenced-by-count":1,"title":["Optimal timing for lithium levels"],"prefix":"10.12688","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-6921-9567","authenticated-orcid":false,"given":"Kevin J","family":"Black","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"2560","published-online":{"date-parts":[[2024,9,16]]},"reference":[{"key":"ref2","first-page":"338-344","article-title":"Formulation of sustained-release lithium carbonate matrix tablets: influence of hydrophilic materials on the release rate and in vitro-in vivo evaluation.","volume":"7","author":"J Emami","year":"2004","journal-title":"J Pharm Pharm Sci."},{"key":"ref1","doi-asserted-by":"publisher","first-page":"346-347","DOI":"10.4103\/0253-7176.135399","article-title":"Serum lithium levels: ideal time for sample collection! Are we doing it right?","volume":"36","author":"D Reddy","year":"2014","journal-title":"Indian J Psychol Med."}],"container-title":["F1000Research"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/f1000research.com\/articles\/11-779\/v2\/xml","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/f1000research.com\/articles\/11-779\/v2\/pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/f1000research.com\/articles\/11-779\/v2\/iparadigms","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,9,10]],"date-time":"2025-09-10T06:10:10Z","timestamp":1757484610000},"score":1,"resource":{"primary":{"URL":"https:\/\/f1000research.com\/articles\/11-779\/v2"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,9,16]]},"references-count":2,"URL":"https:\/\/doi.org\/10.12688\/f1000research.122507.2","relation":{"has-version":[{"id-type":"doi","id":"10.12688\/f1000research.122507.1","asserted-by":"subject"}],"has-review":[{"id-type":"doi","id":"10.5256\/f1000research.171732.r356872","asserted-by":"subject"},{"id-type":"doi","id":"10.5256\/f1000research.171732.r356872","asserted-by":"object"}]},"ISSN":["2046-1402"],"issn-type":[{"value":"2046-1402","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,9,16]]},"assertion":[{"value":"Indexed","URL":"https:\/\/f1000research.com\/articles\/11-779\/v2#article-reports","order":0,"name":"referee-status","label":"Referee status","group":{"name":"current-referee-status","label":"Current Referee Status"}},{"value":"10.5256\/f1000research.134501.r154972, Mehak Pahwa, Department of Psychiatry and Behavioral Sciences, University of Louisville, Louisville, KY, 23 Nov 2022, version 1, 1 approved, 1 approved with reservations","URL":"https:\/\/f1000research.com\/articles\/11-779\/v1#referee-response-154972","order":0,"name":"referee-response-154972","label":"Referee Report","group":{"name":"article-reports","label":"Article Reports"}},{"value":"<b>Kevin J Black<\/b>; \n<i>Posted: 29 Nov 2022<\/i>; I thank Dr. Pawha for agreeing with my main point and for her thoughtful question about why this article exists. Please let me explain. The raison d'&ecirc;tre for this article is that residents kept pulling out the referenced paper by Reddy and Reddy from PubMed to justify drawing lithium levels later for patients taking slow-release formulations. So how could I get an opposing view to future clinicians who searched PubMed to answer this question? The journal the original article appeared in does not accept late correspondence, the NLM sadly ended their PubMed Commons experiment, and few physicians use PubPeer. In short, I saw no solution other than to publish a letter like this one that PubMed would index and show as a &quot;Comment in&quot; link under the original abstract.","URL":"https:\/\/f1000research.com\/articles\/11-779\/v2#referee-comment-9079","order":1,"name":"referee-comment-9079","label":"Referee Comment","group":{"name":"article-reports","label":"Article Reports"}},{"value":"10.5256\/f1000research.134501.r286092, Dean MacKinnon, Johns Hopkins University School of Medicine, Baltimore, MD, 28 Jun 2024, version 1, 1 approved, 1 approved with reservations","URL":"https:\/\/f1000research.com\/articles\/11-779\/v1#referee-response-286092","order":2,"name":"referee-response-286092","label":"Referee Report","group":{"name":"article-reports","label":"Article Reports"}},{"value":"<b>Kevin J Black<\/b>; \n<i>Posted: 28 Jun 2024<\/i>; Thank you for your thoughtful review and clear feedback.","URL":"https:\/\/f1000research.com\/articles\/11-779\/v2#referee-comment-11918","order":3,"name":"referee-comment-11918","label":"Referee Comment","group":{"name":"article-reports","label":"Article Reports"}},{"value":"10.5256\/f1000research.171732.r356872, Seyyed Nassir Ghaemi, Harvard Medical School, Tufts University, Boston, 27 Jan 2025, version 2, indexed","URL":"https:\/\/f1000research.com\/articles\/11-779\/v2#referee-response-356872","order":4,"name":"referee-response-356872","label":"Referee Report","group":{"name":"article-reports","label":"Article Reports"}},{"value":"<b>Kevin J Black<\/b>; \n<i>Posted: 06 Sep 2025<\/i>; Nolen et al 2019 report a literature review and Delphi process with expert consensus statements on lithium dosing. Sections 4.3-4.4 and Table 5 (item 4) in their report agree that in clinical practice, blood sampling for lithium concentration should happen at&nbsp;12 &plusmn; 1 hours after the last dose regardless of immediate- vs. delayed-release formulation. This consensus is consistent with&nbsp;the discussion above and the comments of the three reviewers. (Still, I can't help noting that this F1000Research note does cite data, from Emami et al.)  Nolen WA, Licht RW, Young AH, Malhi GS, Tohen M, Vieta E, Kupka RW, Zarate C, Nielsen RE, Baldessarini RJ, Severus E, The ISBD\/IGSLI Task Force on the Treatment with Lithium. What is the optimal serum level for lithium in the maintenance treatment of bipolar disorder? A systematic review and recommendations from the ISBD\/IGSLI Task Force on treatment with lithium. Bipolar Disord. 2019 Aug;21(5):394-409. doi: 10.1111\/bdi.12805. Epub 2019 Jun 20. PMID: 31112628; PMCID: PMC6688930.","URL":"https:\/\/f1000research.com\/articles\/11-779\/v2#article-response-14517","order":5,"name":"article-response-14517","label":"Article Comment","group":{"name":"article-comments","label":"Article Comments"}},{"value":"The author(s) declared that no grants were involved in supporting this work","order":6,"name":"grant-information","label":"Grant Information"},{"value":"This is an open access article distributed under the terms of the Creative Commons Attribution Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.","order":0,"name":"copyright-info","label":"Copyright"}]}}