What is the appropriate use of diclofenac (Nonsteroidal Anti-Inflammatory Drug (NSAID)) sodium 75mg via intramuscular (IM) injection for acute pain management in a healthy female?

Diclofenac Sodium 75mg Intramuscular Injection in a Healthy Female

Diclofenac sodium 75mg intramuscular injection is appropriate for acute pain management in a healthy female, with a maximum daily dose of 150mg (two 75mg injections separated by at least 12 hours), and should be limited to short-term use (typically 1-3 days) before transitioning to oral or topical formulations. 1

Dosing and Administration

The standard intramuscular dose is 75mg as a single injection for acute pain conditions. 1 For severe acute pain requiring more aggressive management:

• Maximum daily dose: 150mg total (administered as two separate 75mg injections) 1
• Minimum interval between doses: 12 hours 1
• Duration: Limit IM use to 1-3 days, then transition to oral or topical routes 1, 2

Clinical Indications for IM Route

Intramuscular diclofenac 75mg is specifically effective for:

• Acute renal colic (first-line treatment when diagnosis is clear without complications) 1
• Postoperative pain (reduces opioid requirements and improves pain scores) 1
• Acute musculoskeletal injuries (though topical formulations are now preferred first-line) 2
• Biliary colic (comparable or superior to narcotic combinations) 3, 4
• Post-traumatic pain requiring rapid onset 4

The IM route provides faster onset of action compared to oral administration and is particularly valuable when oral intake is not feasible or when rapid pain control is essential. 3, 4

Safety Considerations in Healthy Females

Even in healthy patients, monitor for:

• Gastrointestinal toxicity: Higher doses carry increased risk of GI adverse effects 5, 1
• Renal function: NSAIDs can affect renal perfusion even in healthy individuals 1
• Cardiovascular effects: Use caution even without pre-existing cardiovascular disease 1
• Anaphylaxis: Though rare, anaphylactic reactions can occur after IM diclofenac injection 6

For chronic NSAID therapy beyond acute use, the National Comprehensive Cancer Network recommends monitoring blood pressure, BUN, creatinine, liver function, CBC, and fecal occult blood at baseline and every 3 months. 1 However, for short-term IM use in a healthy female, baseline assessment is typically sufficient.

Transition Strategy

After initial IM administration for acute pain, transition to alternative routes within 1-3 days: 1

• Topical diclofenac gel: Preferred for localized musculoskeletal pain (provides similar efficacy with fewer systemic effects) 2
• Oral diclofenac: 50mg three times daily or 100mg sustained-release twice daily (maximum 150mg/day) 5, 7
• Alternative analgesics: If two NSAIDs fail sequentially, switch to opioid analgesics or non-pharmacologic interventions rather than trying additional NSAIDs 1

Common Pitfalls to Avoid

• Exceeding 150mg daily dose: This significantly increases gastrointestinal and renal toxicity risk 1
• Administering doses less than 12 hours apart: Increases adverse event risk 1
• Prolonged IM use: The IM route should be reserved for acute situations; extended use increases injection site complications and systemic risks 1
• Ignoring contraindications: Even in "healthy" patients, verify no history of peptic ulcer disease, significant alcohol use, or unrecognized cardiovascular risk factors 1

Advantages Over Alternative Analgesics

Diclofenac IM demonstrates:

• Superior efficacy to opioids for certain pain types (renal colic, biliary colic) with significantly fewer side effects 3, 4
• Comparable or superior pain relief to narcotic combinations in acute conditions 3
• Fast onset with long duration of action when given intramuscularly 3
• No dosage adjustment required in healthy patients (unlike some alternatives) 3