Because magnesium hydroxide draws large quantities of water directly out of body tissues into the intestinal cavity, adequate hydration and water intake are non-negotiable. Swallowing the chalky suspension without follow-up fluids forces the body to sap hydration from vital organs, leading to dizziness, dry mouth, lightheadedness, and painful intestinal cramps.
Clinical protocols urge patients to drink a full 8-ounce glass (240 mL) of plain water alongside the dose. Maintaining elevated fluid intake over the subsequent 12 hours ensures that the osmotic process functions efficiently without dehydrating vascular compartments. Patients who restrict fluids while taking saline laxatives risk developing hard, inspissated impactions higher in the colon.
Overuse poses a serious threat to systemic electrolyte balance. Excessive or prolonged consumption flushes potassium, sodium, and chloride out of the digestive tract, potentially triggering cardiac arrhythmias or muscle weakness. Furthermore, individuals with compromised renal clearance cannot excrete excess absorbed magnesium, elevating the risk of toxic hypermagnesemia, which presents as lethargy, low blood pressure, and respiratory depression.
