Most GI side effects are manageable without dose reduction. This decision tree shows when to hold, when to slow, when to escalate, and when to call your prescriber.
About this article
Reviewed byDr. J. Bottoni, M.D.
RoleEditor-in-Chief, Medicine
First publishedMay 20, 2026
Last reviewedMay 20, 2026
Page typeIn-depth editorial guide
Sources15+ cited sources
Nausea ladder
Mild (no impact on eating): continue current dose. Smaller meals, hydration, avoid greasy/sweet foods. Often resolves in 1–2 weeks.
Moderate (reduces appetite but tolerable): consider ondansetron 4 mg prn (prescribe via your provider). Continue dose unless persistent >1 week.
Severe (limits intake, vomiting): hold dose for 1 week. Resume at same dose. If recurs at next escalation, slow titration (hold 4 extra weeks at current step).
Severe + unable to keep liquids down: stop, contact prescriber urgently. Risk of dehydration and AKI.
Constipation algorithm
- First-line: 64+ oz water/day, fiber 25–35 g/day, daily ambulation.
- Second-line: psyllium 1 tsp daily, magnesium citrate 200–400 mg at bedtime.
- Third-line: PEG 3350 (Miralax) 17 g daily.
- Refractory + severe abdominal distension + no flatus: call provider — rule out ileus.
When to stop the drug
- Severe persistent abdominal pain, especially radiating to back — possible pancreatitis. Stop, lipase + imaging.
- RUQ pain + fever — possible gallbladder disease.
- Vomiting limiting fluid intake >24h.
- Vision changes — uncommon but warrants evaluation.
- New severe depression or suicidal ideation.