Loxoprofen (INN) is a non-steroidal anti-inflammatory drug in the propionic acid derivatives group. It is marketed in Brazil, Mexico and Japan by Sankyo as its sodium salt, loxoprofen sodium, under the trade name Loxonin®, and in Argentina as Oxeno®. It is available in these countries for oral administration, and a transdermal preparation was recently approved for sale in Japan.

Pharmacokinetics

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Loxoprofen is a prodrug. It is quickly converted to its active trans-alcohol metabolite following oral administration, and reaches its peak plasma concentration within 30 to 50 minutes.

Mechanism of action

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As most NSAIDs, loxoprofen is a non-selective cyclooxygenase inhibitor, and works by reducing the synthesis of prostaglandins from arachidonic acid.

Drug interactions

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Loxoprofen should not be administered concomitantly with second-generation quinolone antibiotics such as ciprofloxacin and norfloxacin, as it increases their inhibition of GABA and this may cause seizures. It may also increase the plasma concentration of warfarin, methotrexate, sulfonylurea derivatives and lithium salts, so care should be taken when loxoprofen is administered to patients taking any of these drugs.

Non-steroidal anti-inflammatory drugs