What to do for a patient who developed rectal bleeding while taking diclofenac (Nonsteroidal Anti-Inflammatory Drug (NSAID)) 100mg per rectum, doxycycline (antibiotic), metronidazole (antibiotic), and drotaverine (smooth muscle relaxant)?

Management of Rectal Bleeding in a Patient Taking Diclofenac and Antibiotics

Immediately discontinue rectal diclofenac as it is the most likely cause of the patient's rectal bleeding and switch to an alternative pain management approach. 1

Assessment and Initial Management

• Discontinue rectal diclofenac (100mg) immediately as NSAIDs are associated with significant risk of gastrointestinal bleeding, which can occur at any time during treatment, with or without warning symptoms 1
• Perform a focused assessment to determine the severity of bleeding, including vital signs, hemoglobin level, and clinical signs of hemodynamic instability 2
• For severe bleeding, maintain hemoglobin level >7 g/dL (4.5 mmol/L) and mean arterial pressure >65 mmHg while avoiding fluid overload 2
• Consider urgent colonoscopy within 24 hours if bleeding is significant or persistent to identify the source and extent of bleeding 2

Risk Factors and Mechanism

• The patient has multiple risk factors for GI bleeding:

  • Concurrent use of rectal diclofenac (NSAID) 1, 3
  • Possible local irritation from rectal administration 1
  • Potential drug interactions between diclofenac and antibiotics (doxycycline, metronidazole) 2

• NSAIDs including diclofenac cause serious gastrointestinal adverse events through:

  • Inhibition of protective prostaglandins in the GI mucosa 1
  • Direct irritation to the rectal mucosa when administered rectally 1
  • Risk of bleeding increases with longer duration of therapy 1

Alternative Pain Management

• For acute pain management, consider:
  • Acetaminophen/paracetamol as first-line alternative (if not contraindicated) 2
  • If stronger analgesia is needed, consider short-term use of opioids with appropriate monitoring 2
  • For inflammatory conditions, a short course of corticosteroids may be considered as they do not increase ulcer risk when used alone 2

Monitoring and Follow-up

• Monitor for continued bleeding and signs of hemodynamic instability 2
• Check complete blood count to assess for anemia 2
• If bleeding persists despite discontinuation of diclofenac:
  • Consider endoscopic evaluation to identify the source and provide local treatment if needed 2
  • Local procedures such as endoscopic band ligation or sclerotherapy may be necessary if a specific bleeding source is identified 2

Prevention of Future Episodes

• Avoid all NSAIDs (oral, rectal, or parenteral) in this patient due to demonstrated risk of GI bleeding 1, 3
• If NSAIDs are absolutely necessary in the future (which should be rare):
  • Use the lowest effective dose for the shortest duration 1
  • Consider co-administration of a proton pump inhibitor for gastroprotection 2, 3
  • Avoid rectal route of administration in patients with history of rectal bleeding 1

Special Considerations

• Review the need for continued antibiotic therapy (doxycycline, metronidazole) and drotaverine 2
• If antibiotics must be continued, monitor closely for any worsening of GI symptoms 2
• Consider potential drug interactions between current medications that might increase bleeding risk 3