From the Guidelines
Ketorolac has a duration of action of approximately six hours. This is based on the study published in the American Family Physician in 2002 1. The medication is a nonsteroidal anti-inflammatory drug (NSAID) that works by inhibiting cyclooxygenase enzymes, which reduces prostaglandin production and decreases inflammation and pain.
Key Points
- Ketorolac is generally reserved for abortive therapy of severe migraines, and rebound headache is unlikely 1.
- The use of analgesics like ketorolac should be closely monitored because overuse may lead to rebound headaches 1.
- Ketorolac is effective for pain relief, but its use is limited due to concerns about side effects, particularly gastrointestinal bleeding and renal impairment.
Dosage and Administration
- The typical dosing for adults is not specified in the provided study, but ketorolac's duration of action is approximately six hours 1.
- Patients should be monitored for side effects including gastrointestinal symptoms, changes in renal function, and bleeding.
Special Considerations
- Elderly patients and those with renal impairment should receive reduced doses, although the exact dosing is not specified in the provided study.
- Ketorolac is effective in combination with other medications for migraine treatment, but its duration of action is approximately six hours 1.
From the FDA Drug Label
The total combined duration of use of Ketorolac Tromethamine Tablets USP and ketorolac tromethamine is not to exceed 5 days of use Do not use ketorolac tromethamine for more than five days.
The duration of action of ketorolac is not explicitly stated in terms of its pharmacological effect, but the total combined duration of use is limited to 5 days due to the potential of increasing the frequency and severity of adverse reactions 2 2.
- The recommended treatment duration is for the short-term (≤ 5 days) management of moderately severe acute pain.
- Alternative analgesics should be used as soon as possible, and ketorolac therapy should not exceed 5 days.
From the Research
Ketorolac Duration of Action
- The duration of action of ketorolac is related to its pharmacokinetic properties, with an elimination half-life of approximately four to six hours 3.
- This half-life increases in elderly patients and those with renal impairment, suggesting that dosage adjustments may be necessary in these populations 3, 4.
- The analgesic effect of ketorolac may be slightly delayed but often persists for longer than that of opioids 5.
- Peak analgesic effects are achieved in about one to two hours following intramuscular injection, with maximum plasma concentrations reached in 45-50 minutes 3.
- In clinical studies, ketorolac has been shown to provide effective pain relief for up to 6 hours, with some patients requiring additional doses as needed 6, 7.
- The duration of action of ketorolac can be influenced by factors such as age, renal function, and dosage, highlighting the need for individualized dosing regimens 4.