Diazoxide

Disclaimer to the Online 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.

Diazoxide

Indications

  • To reduce blood pressure during a hypertensive crisis
  • To treat persistent hypoglycemia associated with hyperinsulinism

Pharmacology

  • Reduces peripheral vascular resistance and blood pressure by a direct vasodilatory effect on the smooth muscle of peripheral arterioles. The onset of action is within 2 to 5 minutes, and usually lasts 3 to 12 hours. The degree of vasoconstriction present appears to be an important factor in the hypotensive response to diazoxide; greatest effects occur in patients with malignant hypertension
  • Diazoxide causes reduced excretion of K, Cl, bicarbonate, uric acid, and Na and leads to water retention
  • Inhibits pancreatic insulin secretion and stimulates catecholamine release, thereby increasing blood glucose concentration; diazoxide may also act by increasing the hepatic release of glucose; the hyperglycemic effect begins within an hour
  • Diazoxide induced hyperglycemia may be reversed by the administration of insulin

Side Effects

  • Side effects are rare when given for short periods
  • May cause a non dose-related hyperglycemia, tachycardia, vomiting, flushing, rash, burning or pain at the site of administration, hypotension, thrombocytopenia

Nursing Implications

  • Monitor blood pressure and serum glucose
  • Shake suspension well before using

Dose

Hypertensive Crisis
  • 1 to 2 mg/kg IV (undiluted) over 15-30 seconds by physician only
  • Repeat dose every 5 to 15 minutes until desired BP effect is achieved
    • Maximum total dose: 5 mg/kg
  • Do not give IM or SC
  • Repeat effective dose every 2 to 24 h as required for control
    • Note: slow IV infusion may not influence the antihypertensive effect and will minimize the possible danger of ischemic injury to the heart and brain resulting from a sudden drop in blood pressure
Hypoglycemia
  • 4 to 7.5 mg/kg po or IV (over 1 hour) q12h as required for control

Supplied

  • 15 mg/mL, 20 mL ampoule
  • 50 mg/mL oral suspension
References
  1. McEvoy G K (ed): AHFS Drug Information, American Society of Hospital Pharmacists, 1991.
  2. Roberts, RJ: Drug Therapy in Infants, W.B. Saunders, Toronto, 1984.
  3. Gomella TL (Ed): Neonatology - Management, Procedures, On-Call Problems, Diseases, Drugs, 1992, Appleton and Lange, Norwalk, Connecticut.
  4. Gomella TL (Ed): Neonatology - Management, Procedures, On-Call Problems, Diseases, Drugs, 1992, Appleton and Lange, Norwalk, Connecticut.
  5. Taketomo CK, Hodding JH and Kraus DM: Pediatric Dosage Handbook, Lexi-Comp Inc., Cleveland, 1992.