What ICD-10 codes are used for hypokalemia caused by furosemide (Lasix) and treated with potassium chloride?

ICD-10 Coding for Hypokalemia Caused by Furosemide and Treated with Potassium Chloride

For hypokalemia caused by furosemide and treated with potassium chloride, the primary ICD-10 code is E87.6 (Hypokalemia) with a secondary code of T50.1X5A (Adverse effect of loop [high-ceiling] diuretics, initial encounter).

Primary and Secondary Diagnosis Codes

Primary Diagnosis:

• E87.6: Hypokalemia
  • This code identifies the electrolyte imbalance (low potassium)

Secondary Diagnosis:

• T50.1X5A: Adverse effect of loop [high-ceiling] diuretics, initial encounter
  • This code specifies that the hypokalemia is an adverse effect of furosemide (a loop diuretic)

Additional Relevant Codes

• Y57.8: Adverse effect of other drugs and medicaments

  • Can be used as an additional external cause code

• Z79.899: Other long term (current) drug therapy

  • If the patient is on long-term furosemide therapy

Coding Algorithm

1. First, code the manifestation (hypokalemia): E87.6
2. Then, code the cause (adverse effect of furosemide): T50.1X5A
3. Add external cause code if needed: Y57.8
4. Add Z code for long-term medication use if applicable: Z79.899

Clinical Context

Furosemide is known to cause hypokalemia as documented in clinical guidelines 1. The FDA drug label for furosemide specifically warns that "hypokalemia may develop with Furosemide tablets, especially with brisk diuresis, inadequate oral electrolyte intake, when cirrhosis is present, or during concomitant use of corticosteroids" 1.

Potassium chloride is the standard treatment for hypokalemia, with the FDA label stating: "Doses of 40 mEq to 100 mEq per day or more are used for the treatment of potassium depletion" 2.

Common Pitfalls to Avoid

• Do not use E87.6 alone without the secondary code identifying the cause
• Do not code as poisoning (T50.1X1A) since this is an adverse effect, not an overdose
• Do not use Z51.81 (Encounter for therapeutic drug level monitoring) unless the visit is specifically for monitoring drug levels
• Avoid using symptom codes (such as muscle weakness) as the primary diagnosis when the underlying condition (hypokalemia) is known

Documentation Requirements

For proper coding, ensure documentation includes:

• Confirmation of hypokalemia (serum potassium level)
• Clear statement that hypokalemia is due to furosemide
• Documentation of potassium chloride administration
• Any symptoms of hypokalemia (weakness, ECG changes, etc.)

Proper documentation and coding are essential for accurate reimbursement and for tracking medication adverse effects.