<p>Indometacin displays a linear pharmacokinetics profile where the plasma concentrations and area under the curve (AUC) are dose-proportional, whereas half-life (T1/2) and plasma and renal clearance are dose-dependent.<sup class="text-reference-group"><a class="reference-popover-link" data-content="Lucas S: The Pharmacology of Indomethacin. Headache. 2016 Feb;56(2):436-46. doi: 10.1111/head.12769. Epub 2016 Feb 11. (PubMed ID 26865183)" href="#reference-A177871">1</a></sup> Indometacin is readily and rapidly absorbed from the gastrointestinal tract. The bioavailability is virtually 100% following oral administration <sup class="text-reference-group"><a class="reference-popover-link" data-content="Lucas S: The Pharmacology of Indomethacin. Headache. 2016 Feb;56(2):436-46. doi: 10.1111/head.12769. Epub 2016 Feb 11. (PubMed ID 26865183)" href="#reference-A177871">1</a></sup> and about 90% of the dose is absorbed within 4 hours.<sup class="text-reference-group"><a class="reference-popover-link" data-content="Indomethacin Capsules (25 mg) - FDA Label" href="#reference-L6778">13</a></sup> The bioavailability is about 80-90% following rectal administration.<sup class="text-reference-group"><a class="reference-popover-link" data-content="Jensen KM, Grenabo L: Bioavailability of indomethacin after intramuscular injection and rectal administration of solution and suppositories. Acta Pharmacol Toxicol (Copenh). 1985 Nov;57(5):322-7. (PubMed ID 4090993)" href="#reference-A177901">5</a></sup></p><p>The peak plasma concentrations following a single oral dose were achieved between 0.9 ± 0.4 and 1.5 ± 0.8 hours in a fasting state.<sup class="text-reference-group"><a class="reference-popover-link" data-content="Jensen KM, Grenabo L: Bioavailability of indomethacin after intramuscular injection and rectal administration of solution and suppositories. Acta Pharmacol Toxicol (Copenh). 1985 Nov;57(5):322-7. (PubMed ID 4090993)" href="#reference-A177901">5</a></sup> Despite large intersubject variation as well using the same preparation, peak plasma concentrations are dose-proportional and averaged 1.54 ± 0.76 μg/mL, 2.65 ± 1.03 μg/mL, and 4.92 ± 1.88 μg/mL following 25 mg, 50 mg, and 75 mg single doses in fasting subjects, respectively.<sup class="text-reference-group"><a class="reference-popover-link" data-content="Jensen KM, Grenabo L: Bioavailability of indomethacin after intramuscular injection and rectal administration of solution and suppositories. Acta Pharmacol Toxicol (Copenh). 1985 Nov;57(5):322-7. (PubMed ID 4090993)" href="#reference-A177901">5</a></sup> With a typical therapeutic regimen of 25 or 50 mg t.i.d., the steady-state plasma concentrations of indomethacin are an average 1.4 times those following the first dose.<sup class="text-reference-group"><a class="reference-popover-link" data-content="Indomethacin Capsules (25 mg) - FDA Label" href="#reference-L6778">13</a></sup></p>