A postmenopausal woman is started on alendronate for osteoporosis. She is instructed to take it with a full glass of water and remain upright for 30 minutes. The MAIN reason for this instruction is to prevent:

• A Oesophageal erosions and ulceration ✓
• B Hypocalcaemia due to rapid bone uptake
• C Renal tubular toxicity
• D Jaw osteonecrosis

Explanation

Bisphosphonates like alendronate are poorly absorbed and highly irritating to the oesophageal mucosa. Prolonged contact due to oesophageal dysmotility or lying down can cause severe erosive oesophagitis, ulceration, and even stricture. Patients must take the drug with at least 200 mL of plain water and maintain an upright posture for at least 30 minutes to ensure rapid transit to the stomach. Food and other medications must be avoided for 30-60 minutes as they severely impair the already poor oral bioavailability.

Reference: KD Tripathi, Essentials of Medical Pharmacology, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.