Safety of Single-Dose Ketorolac 15mg IM with Amlodipine and Bupropion
A single dose of ketorolac 15mg IM is generally safe to administer with amlodipine and bupropion, as there are no direct contraindications to this combination, though monitoring for enhanced side effects is warranted.
Drug Interaction Assessment
Ketorolac and Amlodipine
- No direct pharmacokinetic interaction exists between ketorolac and amlodipine 1, 2.
- However, ketorolac may theoretically reduce the antihypertensive effect of amlodipine through prostaglandin inhibition and sodium/fluid retention, though this is more relevant with chronic NSAID use rather than a single dose 1.
- One study documented intensified amlodipine side effects (peripheral edema, headaches) when combined with SSRIs, but no such interaction has been reported with NSAIDs 3.
Ketorolac and Bupropion
- No documented interaction exists between ketorolac and bupropion 1, 4.
- Bupropion's mechanism (norepinephrine and dopamine reuptake inhibition) does not interact with ketorolac's prostaglandin synthesis inhibition 4.
- Bupropion is metabolized primarily by CYP2B6, while ketorolac does not significantly affect cytochrome P450 enzymes 4, 5.
Amlodipine and Bupropion
- Caution is advised when combining amlodipine with bupropion, as amlodipine is partially transported by P-glycoprotein, and theoretical interactions may occur 2.
- However, clinical evidence of adverse interactions between these two medications is limited, with one study noting bradycardia when bupropion was combined with beta-blockers (not calcium channel blockers) 3.
Safety Considerations for Single-Dose Ketorolac
Gastrointestinal Risk
- The risk of serious GI bleeding with a single 15mg IM dose is minimal 1, 5.
- The FDA label emphasizes that GI complications increase with duration of use beyond 5 days, but short-term therapy (including single doses) carries substantially lower risk 1.
- Contraindications include active peptic ulcer disease or history of GI bleeding 1.
Renal and Cardiovascular Considerations
- Ketorolac should be used cautiously in patients with renal impairment or cardiovascular disease 1.
- Since amlodipine is used for hypertension, ensure the patient does not have severe renal dysfunction (eGFR <30 mL/min/1.73 m²), as ketorolac safety has not been established in this population 1.
Bleeding Risk
- Ketorolac affects platelet aggregation and should be avoided in patients on anticoagulants (heparin, warfarin) or those with coagulation disorders 1.
- A single dose poses minimal bleeding risk in patients not on anticoagulation 5.
Monitoring Recommendations
- Check blood pressure before and 2-4 hours after ketorolac administration to assess for any reduction in amlodipine's antihypertensive effect 6.
- Monitor for signs of GI distress (abdominal pain, melena, hematemesis), though risk is very low with a single dose 1.
- Assess renal function if the patient has pre-existing kidney disease or is elderly 1.
Common Pitfalls to Avoid
- Do not administer ketorolac if the patient has active peptic ulcer disease, recent GI bleeding, or severe renal impairment 1.
- Avoid combining ketorolac with anticoagulants (warfarin, heparin) due to increased bleeding risk 1.
- Do not exceed 5 days of total ketorolac therapy (IM plus oral combined), as serious adverse events increase significantly beyond this duration 1.
- Ensure the patient is not on corticosteroids, as this combination increases GI bleeding risk 1.