Administration Schedule for Paracetamol, Tramadol, and Ketorolac Injections
These three analgesics can be administered together without mandatory time intervals between them, as they work through different mechanisms and are commonly used in multimodal analgesia protocols. 1
Recommended Administration Approach
Administer all three medications on a scheduled basis rather than "as needed" to maintain consistent analgesia:
- Paracetamol (Acetaminophen): 1 gram IV every 6-8 hours (maximum 4 grams/24 hours) 1
- Ketorolac: 15-30 mg IV every 6 hours (maximum 120 mg/24 hours for patients <65 years; 60 mg/24 hours for patients ≥65 years or <50 kg) 1, 2, 3
- Tramadol: 1-1.5 mg/kg IV every 4-6 hours (maximum 400 mg/24 hours) 1
Practical Timing Strategy
You can administer these medications simultaneously or stagger them to provide continuous coverage:
- Option 1 (Simultaneous): Give all three together every 6 hours for maximum convenience 1
- Option 2 (Staggered): Alternate medications every 2-3 hours to maintain more consistent analgesia throughout the day 1
- Example: Paracetamol at 0800, Tramadol at 1000, Ketorolac at 1200, then repeat cycle
Key Safety Considerations
Ketorolac requires the most vigilance due to its NSAID-related risks:
- Avoid in patients with active peptic ulcer disease, GI bleeding, renal impairment, or bleeding disorders 1, 2
- Monitor baseline and periodic (every 3 months if prolonged use) blood pressure, BUN, creatinine, liver function tests, CBC, and fecal occult blood 1, 2
- Use with extreme caution in patients ≥60 years, those with compromised fluid status, or on nephrotoxic drugs 1, 2
- Ketorolac IV bolus must be given over at least 15 seconds 3
Tramadol considerations:
- Monitor for sedation, respiratory depression, and serotonin syndrome (especially if patient is on other serotonergic medications) 1
- Lower doses may be needed in elderly or renally impaired patients 1
Paracetamol considerations:
- Reduce maximum daily dose to <4 grams in patients with hepatic impairment or chronic alcohol use 1
- Generally the safest of the three medications with fewest contraindications 1
Synergistic Benefits
This combination provides multimodal analgesia through complementary mechanisms:
- Research demonstrates synergistic or additive effects when ketorolac and tramadol are combined, allowing lower doses of each medication 4, 5
- The combination of tramadol and paracetamol provides faster onset than tramadol alone and longer duration than either agent as monotherapy 6
- Ketorolac and paracetamol show additive antinociceptive effects when administered together 7
Common Pitfall to Avoid
Do not wait for pain to become severe before administering scheduled doses. Round-the-clock dosing prevents pain from escalating and reduces total opioid requirements 1. If breakthrough pain occurs despite scheduled dosing, consider adding rescue analgesia rather than increasing the frequency of these three medications 1.