I have heartburn with left upper abdominal pain that wakes me at night and chronic kidney disease stage 3 (eGFR ≈ 30‑50 mL/min); can I take the chewable Acid Pass (famotidine) 10 mg tablets?

Can You Take Famotidine (Acid Pass) for Heartburn with CKD Stage 3?

Yes, you can take famotidine 10 mg for your heartburn with CKD stage 3, but you need dose adjustment: take 10 mg once daily (or 20 mg every other day) instead of the standard dosing, and avoid taking it more frequently than once per day.

Famotidine Dosing in CKD Stage 3

Your kidney function (eGFR 30-50 mL/min) requires specific dose modifications according to FDA labeling:

• For creatinine clearance 30-60 mL/min: Maximum dose is 20 mg once daily OR 40 mg every other day for active ulcers and GERD 1
• Since your formulation contains 10 mg famotidine: You can safely take one tablet (10 mg) once daily, which is well below the maximum recommended dose 1
• Timing: Take it before bedtime for optimal acid suppression during sleep when your symptoms are worst 1

Why Dose Adjustment Matters in Your Case

The pharmacokinetics of famotidine change significantly with reduced kidney function:

• Elimination half-life increases: From 2.8 hours in normal kidneys to 4.7 hours with moderate renal impairment (your range) 2
• Renal clearance is reduced: About 70% of famotidine is eliminated through the kidneys, primarily by tubular secretion 3, 2
• Drug accumulation risk: Without dose adjustment, famotidine can accumulate and potentially cause mental status changes, though this is rare at appropriate doses 4

Addressing Your Left Upper Abdominal Pain

Important clinical consideration: Your left-sided upper abdominal pain that wakes you at night warrants medical evaluation beyond just treating with famotidine:

• This pain pattern could represent gastric ulcer, pancreatitis, or cardiac referred pain rather than simple heartburn
• Seek urgent medical attention if: Pain is severe, radiates to back/shoulder, associated with nausea/vomiting, or if you have risk factors for cardiac disease
• Famotidine is effective for heartburn and can provide symptom relief within 1 hour, lasting 10-12 hours 3, 5, but it won't address other serious causes

Practical Dosing Instructions for Your Situation

Safe regimen with your CKD stage 3:

• Take one 10 mg chewable tablet once daily before bedtime 1
• Can be taken with or without food 1
• May be taken with antacids if needed for breakthrough symptoms 1
• Do not exceed 10 mg daily given your kidney function

Expected Symptom Relief

If your symptoms are truly heartburn-related:

• Acid suppression begins within 1 hour of taking famotidine 3
• Maximum effect occurs at 1-3 hours 3
• Duration of action is 10-12 hours, which should cover overnight symptoms 3
• The 10 mg dose provides approximately 9 hours of measurable symptom control 5

Critical Safety Warnings

Monitor for these adverse effects (more likely with impaired kidney function):

• Mental status changes or confusion (rare but reported in ESRD patients) 4
• If symptoms persist beyond 2 weeks or worsen, you need endoscopic evaluation
• Your left-sided pain location is atypical for typical heartburn and requires physician assessment to rule out cardiac, pancreatic, or splenic pathology

What About the Other Ingredients?

The formulation you mentioned (10/800/165 mg) likely contains:

• 10 mg famotidine (the active H2-blocker)
• 800 mg calcium carbonate (antacid)
• 165 mg magnesium hydroxide (antacid)

With CKD stage 3, be cautious about:

• Magnesium-containing antacids can accumulate with repeated use in kidney disease
• Limit use to occasional doses rather than chronic daily use
• The famotidine component is the primary therapeutic agent; the antacids provide immediate but short-term relief

Bottom line: One 10 mg famotidine tablet daily is safe for your kidney function, but your left upper abdominal pain pattern requires medical evaluation to exclude serious pathology beyond simple heartburn 1, 2.