Disclaimer to the On-line Edition
This Manual has been designed for use in the NICU at London Health Sciences Centre (LHSC), London, Ontario, Canada, and represents clinical practice at this institution. The information contained within the Manual may not be applicable to other centres. If users of this Manual are not familiar with a drug, it is recommended that the official monograph be consulted before it is prescribed and administered. Any user of this information is advised that the contributors, Editor and LHSC are not responsible for any errors or omissions, and / or any consequences arising from the use of the information in this Manual.



  • used for the treatment of edema (eg. caused by heart failure or associated with bronchopulmonary dysplasia) and mild to moderate hypertension


  • a combination of 2 diuretics (spironolactone and hydrochlorothiazide) with different but complementary mechanisms of action
  • hydrochlorothiazide enhances excretion of Na, Cl and water by inhibiting their reabsorption at the cortical diluting segment of the renal tubule; K excretion is increased because of the increased amount of Na which reaches the distal tubular site of Na-K exchange
  • spironolactone inhibits the effects of the adrenocortical hormone, aldosterone, by interfering with the aldosterone-dependent Na-K exchange site in the distal tubule; this results in increased excretion of Na, Cl and water and decreased excretion of K; therefore spironolactone is termed a "potassium-sparing diuretic"

Side Effects

  • fluid and electrolyte imbalance: hyper- or hypokalemia, hyponatremia; dehydration
  • may cause hyperglycemia, thrombocytopenia, vomiting, diarrhea, drowsiness, lethargy


  • 1 to 2 mg/kg (hydrochlorothiazide/spironolactone suspension) po q12h


  • 5 mg/mL oral suspension (each mL contains 5 mg each of hydrochlorothiazide and spironolactone) prepared by Pharmacy.


  1. McEvoy G K (ed): AHFS Drug Information, American Society of Hospital Pharmacists, 1991.
  2. Krogh CME et al (ed): Compendium of Pharmaceuticals and Specialties, Canadian Pharmaceutical Association, 1992.

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