What medications are used to treat an upset stomach?

Medications for Upset Stomach

For an upset stomach, first-line treatments include antispasmodics, peppermint oil, loperamide for diarrhea, and soluble fiber for constipation, while second-line options include tricyclic antidepressants for pain and secretagogues for constipation. 1

First-Line Treatments

For General Upset Stomach Symptoms:

• Antispasmodics are effective for treating global symptoms and abdominal pain in irritable bowel syndrome (IBS) and general upset stomach. Common side effects include dry mouth, visual disturbance, and dizziness 1
• Peppermint oil has been shown to be safe and effective for relief of abdominal pain and global gastrointestinal symptoms 1

For Diarrhea:

• Loperamide is effective for treating diarrhea, though side effects like abdominal pain, bloating, nausea, and constipation may limit tolerability. Careful dose titration can minimize these side effects 1
• Anti-diarrheal medications should be used as first-line treatment for loose stools 1

For Constipation:

• Soluble fiber, such as ispaghula, effectively treats global symptoms and abdominal pain. Start with a low dose (3-4 g/day) and gradually increase to avoid bloating 1
• Osmotic laxatives (polyethylene glycol) and stimulant laxatives (senna) are reasonable first-line treatments for constipation 1

Second-Line Treatments

For Persistent Pain:

• Tricyclic antidepressants (TCAs) are effective second-line treatments for global symptoms and abdominal pain. Start at a low dose (e.g., amitriptyline 10 mg once daily) and titrate slowly to 30-50 mg once daily 1
• TCAs should be the first choice for abdominal pain, initiated at low doses and titrated according to symptomatic response 1

For Persistent Diarrhea:

• 5-HT3 receptor antagonists (such as ondansetron) are efficacious for diarrhea. Ondansetron can be titrated from 4 mg once daily to a maximum of 8 mg three times daily 1
• Rifaximin (a non-absorbable antibiotic) is effective for diarrhea, though its effect on abdominal pain is limited 1

For Persistent Constipation:

• Secretagogues like linaclotide are effective for constipation but may cause diarrhea as a side effect 1
• These medications work by activating ion channels on enterocytes, resulting in water movement into the intestinal lumen 1

Other Considerations

Acid-Related Symptoms:

• Antacids (calcium carbonate, magnesium and aluminum salts) work by neutralizing gastric acid and inhibiting pepsin 2
• While historically used for various conditions, antacids have been largely replaced by more effective agents for serious conditions but remain useful for minor episodes of heartburn and non-ulcer dyspepsia 2

Nausea and Vomiting:

• Ondansetron is effective for nausea and vomiting and doesn't cause sedation or akathisia, making it suitable as a first-line agent in emergency settings 3
• Anti-emetic medications can facilitate oral rehydration therapy in cases of gastroenteritis-related vomiting 4

Common Pitfalls and Caveats

• Conventional analgesics, including opiates, are not successful for treating gastrointestinal pain 1
• Insoluble fiber (e.g., wheat bran) should be avoided as it may worsen symptoms 1
• Complete symptom resolution is often not achievable, and this should be communicated clearly to patients 1
• Food elimination diets based on IgG antibodies and gluten-free diets are not recommended for IBS unless celiac disease is present 1
• Monitor for drug interactions with antacids, which can alter gastric pH and affect absorption of other medications 2
• Be aware of potential side effects: akathisia with prochlorperazine or metoclopramide, sedation with promethazine, and constipation with 5-HT3 receptor antagonists 3