GLP-1 Side-Effect Triage for Primary Care: A Same-Day Decision Tree
Nausea, constipation, pancreatitis red flags, gallbladder pain, muscle loss — a same-day decision tree for the primary care clinician fielding a GLP-1 side-effect call.
A primary care clinician now fields more GLP-1 side-effect calls in a week than they did in a year, five years ago. Most are standard GI. A small number are urgent. This is the same-day decision tree we use to keep the standard calls out of the ED and get the urgent ones there fast.
The four buckets
Standard GI (nausea, mild-to-moderate constipation, early satiety, mild reflux): expected during titration weeks 1–3, usually resolves within 10 days. Manage with hydration, small frequent meals, temporary hold on titration if severe.
Persistent GI (vomiting > 24 hours, inability to keep fluids down, orthostasis): needs a same-day clinical touch. Consider dose reduction, IV fluids, and antiemetics; screen for gastroparesis if a pattern.
Red-flag abdominal: severe epigastric pain radiating to the back suggests pancreatitis — check lipase, image, hold the GLP-1 pending workup. RUQ pain with or without jaundice suggests gallbladder disease — image, refer to surgery if positive.
Systemic and metabolic: hypoglycemia (particularly in patients also on insulin or sulfonylurea), rapid lean-mass loss (screen with grip strength or a simple functional test), or new mood/behavioral changes.
What to hold, what to stop
Hold (temporary): standard GI severe enough to prevent hydration; persistent vomiting; scheduled procedure requiring NPO longer than the drug's half-life (the ASA aspiration-risk guidance is the current reference).
Stop (do not restart without specialist input): confirmed pancreatitis, symptomatic gallbladder disease requiring surgery, suspected medullary thyroid carcinoma, severe gastroparesis.
The sarcopenia conversation nobody has time for
Rapid weight loss on any modality — GLP-1, bariatric surgery, very-low-calorie diet — carries a lean-mass loss risk. The countermeasure is not more visits; it is a two-line prescription: 1.2–1.6 g/kg protein daily and two resistance-training sessions per week. Add a grip-strength or sit-to-stand measurement at baseline and at three months.
Documenting the call
For any side-effect call, document the symptom, the bucket, the disposition, and the plan for follow-up. A three-line note is enough. Ambiguous notes are the source of most GLP-1 malpractice risk.
Frequently asked questions
- When should a GLP-1 be held before surgery or a procedure?
- The current ASA guidance is to hold weekly GLP-1s for one week before an elective procedure requiring anesthesia (or a full drug half-life), given the aspiration risk from delayed gastric emptying. Coordinate with the anesthesia team.
- What lab test screens for GLP-1-associated pancreatitis?
- Serum lipase is the primary lab. Elevated lipase with typical epigastric pain radiating to the back warrants imaging and holding the GLP-1 pending workup.
- How much lean-mass loss is expected on a GLP-1?
- Roughly 20–40% of total weight lost is lean mass in the absence of protein and resistance-training intervention. Adequate protein (1.2–1.6 g/kg/day) and two weekly resistance sessions substantially reduce that fraction.
- Can GLP-1s be resumed after resolved pancreatitis?
- Generally no without specialist evaluation. Recurrent pancreatitis risk is not well characterized, and most protocols discontinue the class after a confirmed episode.