How to prescribe Pedialyte (electrolyte solution) for dehydration in adults?

How to Prescribe Pedialyte for Dehydration in Adults

For adults with mild to moderate dehydration, prescribe Pedialyte (or similar oral rehydration solution containing 45-50 mEq/L sodium) to be consumed freely according to thirst, with the goal of drinking as much as tolerated throughout the day, while monitoring for clinical improvement within 3-4 hours. 1

Assessment of Dehydration Severity

Before prescribing, assess for signs of severe dehydration that would require intravenous therapy rather than oral rehydration:

• Severe dehydration indicators: Large postural pulse change (≥30 beats/minute), severe postural dizziness preventing standing, altered mental status, or shock 1
• Mild-moderate dehydration: Thirst, decreased urine output, dry mucous membranes, but able to drink 1

Prescribing Instructions for Adults

Initial Rehydration Phase

• Instruct patients to drink Pedialyte freely according to thirst, consuming as much as they want over the first 3-4 hours 1
• Adults should consume plain water as often as they wish throughout rehydration in addition to Pedialyte 1
• Start with small, frequent sips if nausea is present, then increase volume as tolerated 2

Important Caveat About Pedialyte's Sodium Content

Pedialyte contains 45 mEq/L sodium, which is lower than the ideal 75-90 mEq/L recommended for rehydration. 1 However, Pedialyte can be used effectively for rehydration when the alternative is physiologically inappropriate liquids (sports drinks, juice, soft drinks) or IV fluids. 1 The CDC guidelines note that while higher sodium solutions are preferable, Pedialyte is acceptable for most cases of viral gastroenteritis in the United States. 1

Ongoing Maintenance

• After initial rehydration (3-4 hours), continue Pedialyte to replace ongoing losses 1
• Encourage increased fluid intake beyond baseline requirements, particularly if fever is present (additional 500-1000 mL/day needed) 3
• Patients should drink frequently throughout the day rather than large volumes at once 3

What NOT to Prescribe

Avoid recommending the following fluids, as they have inappropriate electrolyte content and high osmolality that can worsen diarrhea: 1, 4, 5

• Sports drinks (Gatorade) - associated with persistent hypokalemia 6
• Soft drinks/sodas
• Apple juice
• Chicken broth alone

Note: While one study showed Gatorade was as effective as Pedialyte for viral gastroenteritis, hypokalemia persisted in the Gatorade group, making it a less optimal choice. 6

Monitoring Response to Therapy

Reassess hydration status after 3-4 hours by checking: 1, 2

• Pulse and blood pressure (including orthostatic changes)
• Mental status
• Urine output (should be at least 4-6 times daily with pale yellow color) 3
• Mucous membrane moisture
• Thirst resolution

When to Switch to IV Therapy

Immediately switch to intravenous isotonic fluids (normal saline or lactated Ringer's) if: 1, 2

• Patient develops severe dehydration or shock
• Altered mental status occurs
• Patient cannot tolerate oral intake due to persistent vomiting
• No clinical improvement after 3-4 hours of oral rehydration
• Serum osmolality >300 mOsm/kg and patient appears unwell 1

Dietary Recommendations During Rehydration

• Continue normal eating as soon as appetite returns - there is no justification for "resting the bowel" through fasting 1
• Encourage energy-rich, easily digestible foods 1
• Locally available fluids that prevent dehydration (cereal-based gruels, soup, rice water) should be encouraged in addition to Pedialyte 1

Special Considerations for Older Adults

For geriatric patients with dehydration (serum osmolality >300 mOsm/kg):

• If patient appears well: Encourage increased fluid intake with preferred beverages (tea, coffee, juice, water) 1
• Oral rehydration therapy and sports drinks are NOT indicated for low-intake dehydration in older adults 1
• If patient appears unwell: Offer subcutaneous or intravenous fluids in parallel with encouraging oral intake 1
• Hypotonic fluids are needed to correct raised osmolality in low-intake dehydration 1

Practical Prescribing Strategy

Write the prescription as:

• "Pedialyte oral solution: Drink freely according to thirst, aiming for at least 2-3 liters over the first 24 hours. Consume small, frequent amounts if nauseous. Continue until diarrhea resolves and normal hydration restored. Return immediately if unable to keep fluids down, dizziness when standing, decreased urination, or worsening symptoms."

Common Pitfalls to Avoid

• Do not delay oral rehydration waiting for laboratory results in mild-moderate dehydration 2
• Do not restrict fluids or recommend clear liquid diets only 4
• Do not use anti-diarrheal medications as routine treatment for uncomplicated watery diarrhea 1
• Do not recommend sodium overload - if using Pedialyte for extended periods, ensure patient also consumes plain water 1