Ketorolac is highly bound to human plasma protein (mean 99.2%). Thein vitro binding ofwarfarin to plasma proteins is only slightly reduced by Ketorolac tromethamine (99.5% control vs.
99.3%).
Ketorolac Tromethamine Injection reduced the diuretic response to furosemide in normo-volemic healthy subjects by
approximately 20% (mean sodium and urinary output decreased 17%).
Concomitant administration of Ketorolac tromethamine tablets and probenecid resulted in decreased clearance of
Ketorolac and significant increases in Ketorolac plasma levels (total AUC increased approximately three-fold from 5.4 to
17.8 mcg/h/mL) and terminal half-life increased approximately two-fold from 6.6 to 15.1 hours. Therefore, concomitant
use of Ketorolac tromethamine and probenecid is contraindicated.
Inhibition of renal lithiumclearance, leading to an increase in plasma lithium concentration, has been reported with some
prostaglandin synthesis-inhibiting drugs. The effect of Ketorolac tromethamine on plasma lithium has not been studied, but
cases of increased lithium plasma levels during Ketorolac tromethamine therapy have been reported.
Concomitant administration of methotrexateand some NSAIDs has been reported to reduce the clearance of
methotrexate, enhancing the toxicity of methotrexate. The effect of Ketorolac tromethamine on methotrexate clearance
has not been studied.
In postmarketing experience there have been reports of a possible interaction between Ketorolac Tromethamine Injection
andnondepolarizing muscle relaxants that resulted in apnea. The concurrent use of Ketorolac tromethamine with muscle
relaxants has not been formally studied.
Concomitant use of ACE inhibitors may increase the risk of renal impairment, particularly in volume-depleted patients.
Sporadic cases of seizures have been reported during concomitant use of Ketorolac tromethamine and antiepileptic drugs
(phenytoin, carbamazepine).
Hallucinations have been reported when Ketorolac tromethamine was used in patients taking psychoactive drugs
(fluoxetine, thiothixene, alprazolam).
Ketorolac Tromethamine Injection has been administered concurrently withmorphine in several clinical trials of
postoperative pain without evidence of adverse interactions. Do not mix Ketorolac tromethamine and morphine in the
same syringe.
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