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Pharmacokinetics of Single‐Dose Oral and Intramuscular Ketorolac Tromethamine in the Young and Elderly
Author(s) -
Jallad Nader S.,
Garg Dyal C.,
Martinez Juan J.,
Mroszczak Edward J.,
Weidler Donald J.
Publication year - 1990
Publication title -
the journal of clinical pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.92
H-Index - 116
eISSN - 1552-4604
pISSN - 0091-2700
DOI - 10.1002/j.1552-4604.1990.tb03442.x
Subject(s) - ketorolac tromethamine , ketorolac , medicine , pharmacokinetics , analgesic , anesthesia , oral administration , intramuscular injection , pharmacology
The elderly are likely candidates to receive analgesics for pain from a variety of etiologies. Ketorolac tromethamine is a nonsteroidal, analgesic, anti‐inflammatory, antipyretic investigational drug with anti‐prostaglandin synthetase activity. Sixteen healthy, young men (mean age 30 years and mean weight 75 kg) and 13 healthy, elderly subjects (11 men and two women; mean age 72 years and mean weight 75 kg) participated in an open‐label, parallel single‐dose study. On each day of ketorolac tromethamine administration the subjects fasted overnight and for 2 hours post‐dose. A single intramuscular (IM) dose of 30 mg of ketorolac tromethamine was administered followed by an oral dose (PO) of 10 mg after a 1 week washout period for the elderly subjects. Plasma samples were taken from 0 through 48 hours post‐dose and analyzed for ketorolac by HPLC. The elimination of ketorolac was decreased slightly in the elderly following both doses, as evidenced by a prolongation in half‐life (4.7 to 6.1 hours for PO and 4.5 to 7.0 hours for IM) and a reduced total plasma clearance compared to the young adult subjects. These differences were statistically significant ( P < .001). Considerable overlap frequently was observed when comparing the range of values obtained for the young and elderly for plasma half‐life, clearance, AUC, T max and C max . The absorption of ketorolac tromethamine was not altered substantially in the elderly following either dose route. Ketorolac plasma protein binding was not altered substantially in the elderly. The present results show that the elderly may need slightly less frequent dosing of ketorolac than young adults to maintain similar plasma levels. In these studies there has been no evidence of drug accumulation in the elderly after long‐term ketorolac tromethamine administration when given in a tid or qid regimen .