What is the treatment for hypokalemic periodic paralysis?

Treatment of Hypokalemic Periodic Paralysis

For acute attacks of hypokalemic periodic paralysis, administer oral potassium chloride 20-60 mEq immediately, and if intravenous therapy is required, use potassium chloride in mannitol or saline—never in glucose-containing solutions, as glucose worsens weakness and prevents potassium rise. 1, 2

Acute Attack Management

Immediate Treatment Protocol

• Oral potassium chloride is the first-line treatment for acute attacks, with doses of 20-60 mEq administered to rapidly correct hypokalemia and restore muscle strength 1, 3
• Verify the potassium level immediately, as HPP patients typically present with severe hypokalemia (often 1.5-2.7 mEq/L) requiring aggressive correction 4, 5
• Check and correct magnesium levels concurrently, as hypomagnesemia makes hypokalemia resistant to correction and must be addressed before potassium levels will normalize 3

Intravenous Therapy (When Oral Route Inadequate)

• Use potassium chloride diluted in 5% mannitol or normal saline only—never use glucose-containing solutions (5% dextrose), as glucose provokes further weakness and prevents potassium rise in HPP patients 2
• This critical distinction exists because glucose-insulin shifts trigger paralytic attacks in HPP, making glucose-based IV solutions contraindicated 2
• Administer IV potassium with continuous cardiac monitoring due to arrhythmia risk, and recheck potassium levels within 1-2 hours after IV correction 3

Monitoring During Acute Treatment

• Recheck serum potassium within 1-2 hours after initial treatment to assess response and avoid overcorrection 3
• Continue monitoring every 2-4 hours during the acute phase until potassium stabilizes above 3.5 mEq/L 3
• Assess for concurrent hypomagnesemia (target >0.6 mmol/L), as this is the most common reason for treatment failure 3

Prophylactic Long-Term Management

First-Line Preventive Therapy

• Potassium-sparing diuretics, specifically triamterene 50-100 mg daily, are highly effective for preventing attacks and may be superior to acetazolamide in certain patients 6
• Triamterene virtually abolished attacks in controlled trials and increased potassium levels significantly, making it particularly valuable for patients who worsen on acetazolamide 6
• Spironolactone 25-100 mg daily or amiloride 5-10 mg daily are alternative potassium-sparing options 3

Alternative Prophylactic Agents

• Carbonic anhydrase inhibitors (acetazolamide) are traditionally used but can paradoxically worsen attacks in some HPP patients due to kaliopenic effects 6
• Topiramate, which has carbonic anhydrase inhibitory properties, decreased attack severity in pediatric HPP cases and warrants consideration when traditional agents fail 7
• Avoid acetazolamide if attacks increase in frequency or severity after initiation, as this indicates the patient belongs to the subset worsened by this medication 6

Monitoring Protocol for Chronic Management

• Check potassium and creatinine 5-7 days after initiating potassium-sparing diuretics, then continue monitoring every 5-7 days until values stabilize 3
• Once stable, monitor at 1-2 weeks, 3 months, and subsequently every 6 months 3
• Target serum potassium range of 4.0-5.0 mEq/L to prevent both attacks and hyperkalemia complications 3

Critical Pitfalls to Avoid

• Never use glucose-containing IV solutions for potassium replacement in HPP, as this worsens paralysis and prevents potassium correction 2
• Do not assume acetazolamide will benefit all HPP patients—some experience increased attack frequency and severity, requiring switch to triamterene 6
• Never supplement potassium without checking and correcting magnesium first, as this is the most common reason for treatment failure 3
• Avoid combining potassium supplementation with ACE inhibitors, ARBs, or aldosterone antagonists without extremely close monitoring, as hyperkalemia risk is substantial 3

Special Considerations

• HPP attacks can be provoked by glucose-insulin administration, high-carbohydrate meals, strenuous exercise, and stress—counsel patients to avoid these triggers 6, 2
• The FDA indicates that controlled-release potassium chloride preparations should be reserved for patients who cannot tolerate liquid or effervescent preparations due to GI ulceration risk 1
• Patients with familial HPP require genetic counseling and family screening, as most cases are hereditary with autosomal dominant inheritance 4
• Acquired HPP secondary to thyrotoxicosis, hyperaldosteronism, or hypercortisolism requires treatment of the underlying endocrine disorder in addition to potassium management 4