What are the contraindications and precautions for using Hydrochlorothiazide (HCTZ)?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: June 2, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Guidelines

Hydrochlorothiazide (HCTZ) should not be used in patients with anuria, sulfonamide allergy, or hypersensitivity to the medication, as well as those with severe renal impairment (creatinine clearance <30 mL/min), hepatic coma, or unresponsive hyponatremia or hypokalemia. The medication requires careful monitoring in patients with gout, diabetes, systemic lupus erythematosus, and impaired glucose tolerance, as it may exacerbate these conditions 1. Key considerations for the use of HCTZ include:

  • Monitoring for hyponatremia and hypokalemia, uric acid and calcium levels, especially in patients with a history of gout or those on uric acid–lowering therapy 1
  • Avoiding use in patients with severe bilateral renal artery stenosis due to the risk of acute renal failure 1
  • Caution in patients with impaired renal function, liver disease, or a history of allergy to other thiazide diuretics, as well as in elderly patients who may require lower doses due to increased sensitivity to the drug's effects 1
  • Potential for electrolyte imbalances, particularly hypokalemia, hyponatremia, and hypercalcemia, necessitating regular monitoring of electrolyte levels
  • Potential to increase blood glucose levels and worsen lipid profiles, requiring close monitoring in patients taking lithium, digoxin, or certain antidiabetic medications due to potential drug interactions. HCTZ works by inhibiting sodium and chloride reabsorption in the distal convoluted tubule of the kidney, increasing water excretion and reducing blood pressure, but these mechanisms also account for its potential adverse effects and contraindications.

From the FDA Drug Label

Hydrochlorothiazide capsules are contraindicated in patients with anuria. Hypersensitivity to this product or other sulfonamide derived drugs is also contraindicated. Thiazides should be used with caution in patients with impaired hepatic function. They can precipitate hepatic coma in patients with severe liver disease Thiazides should be discontinued before carrying out tests for parathyroid function

The contraindications for HCTZ are:

  • Anuria
  • Hypersensitivity to the product or other sulfonamide derived drugs The precautions for using HCTZ include:
  • Impaired hepatic function
  • Severe liver disease
  • Parathyroid disease
  • Pregnancy and lactation 2, 2

From the Research

Contraindications for HCTZ

  • Hypersensitivity to sulfonamide-derived drugs, as patients with a history of allergic reactions to sulfonamides may experience severe reactions to HCTZ 3
  • Anuria, as HCTZ is ineffective in patients with no urine production and may worsen hyperkalemia and hypercalcemia 4, 5
  • Severe renal impairment, as HCTZ may not be effective in patients with advanced chronic kidney disease (CKD) and may worsen electrolyte imbalances and kidney function 4, 6

Precautions for Using HCTZ

  • Monitor electrolyte levels, particularly potassium, sodium, and calcium, as HCTZ can cause electrolyte imbalances 7, 4, 5
  • Monitor renal function, as HCTZ can worsen kidney function in patients with pre-existing renal impairment 4, 6
  • Use with caution in patients with hyperparathyroidism, as HCTZ can increase serum calcium levels in patients with elevated parathyroid hormone levels 5
  • Monitor blood pressure, as HCTZ can cause orthostatic hypotension 7, 3
  • Use with caution in patients with diabetes, as HCTZ can worsen hyperglycemia 7, 3

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.