Pharmacodynamics and Pharmacokinetics
Ketorolac (Ketorolacum) occupies a unique position among nonsteroidal anti-inflammatory drugs due to its specific activity profile. Its analgesic effect is exceptionally strong—acting as a potent pain reliever comparable in efficacy to certain opioid analgesics.
However, it is crucial to note that Ketorolac's anti-inflammatory activity is significantly weaker than that of other classic NSAIDs. This makes it the drug of choice specifically for acute pain management rather than for treating systemic inflammation.
From a pharmacokinetic standpoint, the drug possesses highly favorable characteristics:
- Excellent absorption from the gastrointestinal tract.
- Very high oral bioavailability, ranging between 80–100%. This means that almost the entire administered oral dose reaches the systemic circulation to exert a therapeutic effect.
Clinical Indications
Given its high analgesic potential, ketorolac is widely used in clinical situations requiring rapid and reliable pain control. The drug can be administered via various routes: orally (tablets) or parenterally (intramuscular or intravenous injections).
Key clinical indications include:
- Postoperative Pain. In surgical practice, ketorolac is actively used as an effective alternative to opioid analgesics, helping avoid opioid-related adverse effects.
- Trauma-Induced Pain. The drug rapidly relieves acute pain associated with fractures, dislocations, and severe contusions.
- Cancer Pain. Used to alleviate severe pain in patients with malignancies.
- Trigeminal Neuralgia. Provides marked relief during acute episodes of intense facial pain associated with lesions of this cranial nerve branch.
Adverse Effects and Risks
Like all NSAIDs, ketorolac carries a profile of significant adverse effects. Notably, the risks of these complications increase manifold with prolonged use. Therefore, the duration of ketorolac therapy is strictly limited.
Key adverse reactions:
- Gastrotoxicity. Manifests as gastric and duodenal mucosal erosions and ulcerations. The mechanism underlying this complication is the potent inhibition of $E_2$ and $I_2$ prostaglandin synthesis. Under normal physiological conditions, these molecules exert crucial gastroprotective effects (defending the gastric mucosa against acidic gastric juice). During ketorolac therapy, this mucosal defense is lost.
- Nephrotoxicity. Manifests as impaired renal function. The drug primarily disrupts glomerular filtration dynamics, which can precipitate acute kidney injury if used indiscriminately.