What medications can be used to relieve abdominal pain?

Medications for Abdominal Pain

For abdominal pain, tricyclic antidepressants (TCAs) should be the first-line neuromodulator treatment, initiated at low doses and titrated according to symptomatic response, with antispasmodics or peppermint oil as initial therapy for pain management. 1

First-Line Medications

Antispasmodics and Peppermint Oil

• Antispasmodics (such as dicyclomine or hyoscine) are recommended as first-line treatment for abdominal pain in irritable bowel syndrome (IBS) and have been shown to be safe and effective 1
• Peppermint oil is also effective as first-line treatment for abdominal pain and global IBS symptoms 1, 2
• These medications work by reducing smooth muscle contractions in the gastrointestinal tract, thereby alleviating pain 1

Non-Steroidal Anti-Inflammatory Drugs (NSAIDs)

• Ibuprofen can be effective for abdominal pain relief at doses of 400-800mg every 6 hours 3
• In postoperative settings, perioperative administration of Ibuprofen IV 800 mg every 6 hours has been shown to decrease pain scores 1
• Caution: NSAIDs may cause gastrointestinal side effects including abdominal pain, dyspepsia, nausea, and diarrhea 4, 5
• NSAIDs should be avoided in patients with history of peptic ulcer disease or at high risk for gastrointestinal bleeding 3

Acetaminophen (Paracetamol)

• Acetaminophen can be used at doses of 500-600mg every 6 hours for abdominal pain management 1
• It has a better safety profile than NSAIDs for gastrointestinal effects 4
• Can be used in combination with other analgesics in a multimodal approach 1

Second-Line Medications

Tricyclic Antidepressants (TCAs)

• TCAs are the most effective neuromodulators for abdominal pain, particularly in IBS 1
• Start with low doses (e.g., amitriptyline 10mg at bedtime) and titrate according to response 1, 2
• TCAs have been shown to be significantly better than placebo for abdominal pain relief 1
• These medications work by modulating pain pathways between the gut and brain 1

Selective Serotonin Reuptake Inhibitors (SSRIs)

• SSRIs can be considered if TCAs are not tolerated or ineffective 1
• They may improve overall IBS symptoms and well-being but have less effect on abdominal pain compared to TCAs 1, 2
• SSRIs may be more beneficial in patients with comorbid anxiety or depression 1

Subtype-Specific Medications

For Diarrhea-Predominant Conditions

• Loperamide is effective for controlling stool frequency and urgency at doses of 4-12mg daily, though it has limited effect on abdominal pain 2
• 5-HT3 receptor antagonists (e.g., ondansetron) are effective for IBS with diarrhea 1, 2
• Eluxadoline can be effective but is contraindicated in patients with prior sphincter of Oddi problems, cholecystectomy, alcohol dependence, pancreatitis, or severe liver impairment 1, 2

For Constipation-Predominant Conditions

• Secretagogues such as linaclotide, plecanatide, and lubiprostone are effective for constipation-predominant conditions and can also help with abdominal pain 1
• Linaclotide has been shown to reduce abdominal pain through cyclic GMP production, which attenuates visceral pain 1
• Osmotic laxatives (e.g., polyethylene glycol) and stimulant laxatives can be used as first-line treatment for constipation but have limited evidence for pain relief 1

For Severe or Refractory Pain

• For severe or refractory abdominal pain, combination therapy with neuromodulators may be considered (e.g., TCA plus SSRI or SNRI) 1
• Vigilance for serotonin syndrome is required when combining serotonergic medications 1
• Referral to a multidisciplinary chronic pain team should be considered for centrally-mediated abdominal pain or narcotic bowel syndrome 1

Important Considerations and Pitfalls

• Conventional opioid analgesia is not recommended for chronic abdominal pain as it is generally ineffective and carries significant risks 1
• Always start medications at low doses and titrate slowly to minimize side effects 2
• When prescribing neuromodulators, clearly explain they are being used for gut-brain modulation, not depression 2
• For abdominal pain associated with specific conditions like inflammatory bowel disease or colorectal cancer, targeted therapies addressing the underlying condition should be prioritized 6
• Consider the abdominal wall as a potential source of pain, especially when pain is related to posture and has minimal relationship to eating or bowel function 7