A 58-year-old man with a 10-year history of GERD is on omeprazole 20 mg daily. All of the following are recognized adverse effects of long-term PPI use EXCEPT:

Explanation

## Adverse Effects of Long-Term PPI Use **Key Point:** Acute angle-closure glaucoma is NOT an established adverse effect of PPIs. This is a classic distractor in NEET PG exams. ### Established Long-Term Adverse Effects of PPIs | Adverse Effect | Mechanism | Clinical Significance | | --- | --- | --- | | **Hypomagnesemia** | Reduced intestinal Mg²⁺ absorption in alkaline environment | Can occur in 13–70% of long-term users; risk of hypokalemia, arrhythmias | | **Vitamin B₁₂ deficiency** | Reduced intrinsic factor synthesis by parietal cells; impaired B₁₂ release from food | Risk increases after 2+ years; may cause megaloblastic anemia, neuropathy | | **Hypocalcemia / osteoporosis** | Reduced Ca²⁺ absorption in alkaline environment; increased fracture risk | Especially in postmenopausal women; long-term use | | **C. difficile infection** | Reduced gastric acid barrier → increased colonic overgrowth | Particularly in hospitalized patients; risk increases with duration | | **Iron deficiency** | Reduced Fe²⁺ absorption in alkaline environment | Less common than B₁₂ deficiency | | **Acute interstitial nephritis** | Immune-mediated hypersensitivity reaction | Rare but serious; can occur early or after prolonged use | | **Hyponatremia** | SIADH-like syndrome (rare) | Documented but uncommon | **High-Yield:** The "Big Three" long-term PPI complications tested in NEET PG: 1. **Hypomagnesemia** — most common (occurs in up to 70% of chronic users) 2. **Vitamin B₁₂ deficiency** — occurs after 2+ years 3. **Increased C. difficile risk** — due to loss of gastric acid barrier **Clinical Pearl:** Patients on long-term PPIs (>1 year) should have baseline Mg²⁺, B₁₂, and calcium levels checked, with periodic monitoring. Hypomagnesemia may present with muscle cramps, weakness, or cardiac arrhythmias. **Warning:** ~~Acute angle-closure glaucoma is a PPI adverse effect~~ — this is NOT established. Topiramate and sulfonamides (acetazolamide, sulfamethoxazole) cause angle-closure glaucoma, but PPIs do not. This is a common trap in MCQs. ### Why Angle-Closure Glaucoma Is NOT a PPI Effect Acute angle-closure glaucoma occurs with drugs that: - Cause pupillary dilation (mydriasis) — e.g., anticholinergics, sympathomimetics - Cause ciliary muscle contraction or lens swelling — e.g., topiramate, sulfonamides PPIs have no mechanism to cause any of these effects. This is a classic distractor.