ISSUE1447
The same pharmaceutical company (Iroko) that recently marketed low-dose diclofenac (Zorvolex) for treatment of mild to moderate acute pain1 has now received approval from the FDA to market a low-dose oral formulation of indomethacin (Tivorbex) for the same indication. Tivorbex is available in 20- and 40-mg capsules; conventional immediate-release indomethacin capsules contain 25 mg and 50 mg of the drug.
The rationale for this new product is the same as the one offered for Zorvolex: the drug is formulated as submicron particles that increase surface area, leading to faster dissolution and absorption. According to the package insert, the time to reach peak serum concentrations (Tmax) was 1.67 hours with a 40-mg capsule of Tivorbex, compared to 2.02 hours with a standard 50-mg capsule of indomethacin.
The problem with Tivorbex is the same as the problem with Zorvolex: there are no studies comparing its efficacy to that of standard doses of indomethacin or to any other NSAID. In addition, indomethacin is generally considered one of the most potent NSAIDs and one of those most likely to cause GI bleeding, increase cardiovascular risk, and damage the kidneys. There is no good reason to use indomethacin in any dosage for treatment of mild to moderate pain.
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