In an elderly patient with heartburn or dyspepsia, which antacid agents are safe for short‑term use considering risks of electrolyte disturbances, impaired renal function, and drug interactions?

Antacid Use in Elderly Patients

For elderly patients with heartburn or dyspepsia, proton pump inhibitors (PPIs) such as omeprazole 20 mg daily are superior to traditional antacids and H2-receptor antagonists for symptom relief, while traditional antacids should be reserved for occasional breakthrough symptoms due to their significant risks of electrolyte disturbances and drug interactions in this population. 1, 2

First-Line Therapy: Proton Pump Inhibitors

PPIs are the preferred empirical therapy for elderly patients with uninvestigated dyspepsia or heartburn, as they provide superior symptom relief compared to H2-receptor antagonists, antacid-alginate combinations, and placebo. 1

• Omeprazole 20 mg daily achieves heartburn relief in 55% of patients at 4 weeks and 88% by 16 weeks, significantly outperforming H2-receptor antagonists (27% at 4 weeks). 3
• Lansoprazole has also demonstrated superiority over ranitidine for both mucosal healing and symptom relief in reflux esophagitis. 4

Role of Traditional Antacids in Elderly Patients

Traditional antacids (calcium carbonate, magnesium hydroxide, aluminum hydroxide) should be used only for occasional breakthrough symptoms rather than as primary therapy in elderly patients. 2, 5

Critical Safety Concerns with Antacids in the Elderly:

Magnesium-containing antacids (magnesium hydroxide) must be avoided in elderly patients with any degree of renal impairment due to high risk of hypermagnesemia, which is particularly dangerous given the high prevalence of reduced creatinine clearance in this population. 6, 2

• Elderly patients are at substantially higher risk for antacid-related adverse effects due to age-related decline in renal function. 7
• Aluminum-containing antacids should be avoided in chronic renal failure patients to prevent aluminum accumulation. 2
• Large doses taken for prolonged periods can cause significant electrolyte disturbances, especially in patients with underlying renal disease. 2

Drug Interaction Pitfalls:

Antacids create multiple drug interaction risks that are particularly problematic in elderly patients taking multiple medications:

• All antacids alter gastric pH, affecting drug dissolution and absorption of other medications. 2
• Most antacids (except sodium bicarbonate) decrease drug absorption through adsorption or chelation mechanisms. 2
• Timing medication administration around antacid use is inconvenient and discourages compliance—a major concern in elderly patients with complex medication regimens. 2

H2-Receptor Antagonists as an Alternative

Famotidine represents a safer alternative to traditional antacids for elderly patients who cannot tolerate or afford PPIs, though it is less effective than PPIs. 1, 7

Famotidine-Specific Considerations in the Elderly:

• Use the lowest effective dose and monitor renal function, as famotidine is substantially excreted by the kidney and elderly patients face greater risk of adverse reactions, particularly those with impaired renal function. 7
• CNS adverse reactions have been reported in elderly patients with and without renal impairment receiving famotidine. 7
• Dosage reduction is mandatory in patients with moderate or severe renal impairment (creatinine clearance <60 mL/minute). 7

Adjunctive Use of Antacids

When antacids are used alongside antisecretory therapy:

• Antacid-alginate combinations are inferior to PPIs for symptom relief in uninvestigated dyspepsia. 1
• Patients may use antacids as needed for breakthrough symptoms while on PPI therapy, but increased antacid use (more than doubling) signals treatment failure and deteriorating quality of life. 8
• Consider adding an H2-blocker or PPI rather than relying on antacids alone when patients experience dyspepsia, as patients sometimes have difficulty discriminating heartburn from nausea. 1

Practical Algorithm for Elderly Patients

1. Start with omeprazole 20 mg daily (or equivalent PPI) for empirical therapy of heartburn/dyspepsia. 1, 3
2. Assess renal function before initiating any therapy using creatinine clearance calculation (Cockcroft-Gault equation). 9, 7
3. Reserve traditional antacids for occasional breakthrough symptoms only, avoiding magnesium-containing products entirely if creatinine clearance <60 mL/minute. 6, 2
4. If PPI is contraindicated or unavailable, use famotidine at reduced doses with renal function monitoring. 7
5. Endoscopy is recommended for elderly patients presenting with new dyspepsia, those with alarm symptoms, or those on regular NSAIDs. 1

Common Pitfalls to Avoid

• Never prescribe magnesium-containing antacids to elderly patients without first confirming normal renal function—this is the single most dangerous error given the high prevalence of occult renal impairment in this population. 6, 2
• Do not rely on serum creatinine alone; calculate creatinine clearance, as elderly patients may have falsely reassuring creatinine levels due to reduced muscle mass. 9
• Avoid aluminum-containing antacids in patients with chronic kidney disease due to aluminum accumulation risk. 2
• Do not use antacids as primary long-term therapy when PPIs are available and appropriate, as this exposes patients to unnecessary electrolyte and drug interaction risks. 2, 5