DIAZOXIDE
(dye-az-ox'ide)
Hyperstat I. V., Proglycem
Classifications: cardiovascular agent; antihypertensive; vasodilator; sulfonylurea
Prototype: Hydralazine
Pregnancy Category: C
|
50 mg capsules; 50 mg/mL suspension; 15 mg/mL injection
Rapid-acting thiazide nondiuretic hypotensive and hyperglycemic agent. In contrast to thiazide diuretics, causes sodium and
water retention and decreases urinary output, probably because it increases proximal tubular reabsorption of sodium and decreases
glomerular filtration rate. Hypotensive effect may be accompanied by marked reflex increase in heart rate, cardiac output,
and stroke volume; thus cerebral and coronary blood flow are usually maintained.
Reduces peripheral vascular resistance and BP by direct vasodilatory effect on peripheral arteriolar smooth muscles, perhaps
by direct competition for calcium receptor sites.
Intravenously for emergency lowering of BP in hospitalized patients with malignant hypertension, particularly when associated
with renal impairment. Not effective in pheochromocytoma. Commonly used with a diuretic such as furosemide (Lasix) to counteract
diazoxide-induced sodium and water retention. Orally in treatment of various diagnosed hypoglycemic states due to hyperinsulinism
when other medical treatment or surgical management has been unsuccessful or is not feasible.
Hypersensitivity to diazoxide or to other thiazides; cerebral bleeding, eclampsia; aortic coarctation; AV shunt, significant
coronary artery disease. Safe use during pregnancy (category C) or lactation is not established. Use of oral diazoxide for
functional hypoglycemia or in presence of increased bilirubin in newborns.
Diabetes mellitus; impaired cerebral or cardiac circulation; impaired renal function; patients taking corticosteroids or estrogen–progestogen
combinations; hyperuricemia, history of gout, uremia.
Severe Hypertension
Adult/Child: IV 1–3 mg/kg up to 150 mg, repeat at 5–15 min intervals if necessary
Hypoglycemia
Adult/Child: PO 3–8 mg/kg/d divided q8–12h
Neonate/Infant: PO 8–15 mg/kg/d divided q8–12h
|
Intravenous
- Note: Give any prescribed diuretic 30–60 min prior to IV diazoxide. Keep patient recumbent 8–10 h because of possible
additive hypotensive effect.
PREPARE: Direct: Give undiluted.
ADMINISTER: Direct: Give IV by rapid direct injection over 10–30 s. Keep patient recumbent while receiving IV and for at least 30 min following
administration.
- Check IV injection site frequently. Solution is strongly alkaline. Extravasation of medication into tissues can cause severe
inflammatory reaction. Administer drug by peripheral vein ONLY.
|
- Do not give darkened solutions. Store capsules, oral suspension, and injectables at 2°–30° C (36°–86°
F) unless otherwise directed. Protect from light, heat, and freezing.
CNS: Headache, weakness, malaise, dizziness, polyneuritis, sleepiness, insomnia, euphoria, anxiety, extrapyramidal signs. CV: Palpitations, atrial and ventricular arrhythmias, flushing, shock; orthostatic hypotension, CHF, transient hypertension. Special Senses: Tinnitus, momentary hearing loss; blurred vision, transient cataracts, subconjunctival hemorrhage, ring scotoma, diplopia,
lacrimation, papilledema. GI: Nausea, vomiting, abdominal discomfort, diarrhea, constipation, ileus, anorexia, transient loss of taste, impaired hepatic function. Hematologic: Transient neutropenia, eosinophilia, decreased Hgb/Hct, decreased IgG. Body as a Whole: Hypersensitivity (rash, fever, leukopenia); chest and back pain, muscle cramps. Urogenital: Decreased urinary output, nephrotic syndrome (reversible), hematuria, increased nocturia, proteinuria, azotemia; inhibition
of labor. Skin: Pruritus, flushing, monilial dermatitis, herpes, hirsutism; loss of scalp hair, sweating, sensation of warmth, burning, or
itching. Endocrine: Advance in bone age (children), hyperglycemia, sodium and water retention, edema, hyperuricemia, glycosuria, enlargement of breast lump, galactorrhea; decreased immunoglobulinemia, hirsutism.
Diazoxide can cause false-negative response to glucagon.
Drug: sulfonylureas antagonize effects; thiazide diuretics may intensify hyperglycemia and antihypertensive effects; phenytoin increases risk of hyperglycemia, and diazoxide may increase phenytoin metabolism, causing loss of seizure control.
Onset: 30–60 s IV; 1 h PO. Peak: 5 min IV. Duration: 2–12 or more h IV; 8 h PO. Distribution: Crosses blood–brain barrier and placenta. Metabolism: Partially metabolized in the liver. Elimination: Excreted in urine. Half-Life: 21–45 h.
Assessment & Drug Effects
- Monitor for therapeutic effectiveness. Discontinue if not effective in 2 or 3 wk.
- Lab tests: Initial blood glucose, serum electrolytes, and CBC and at regular intervals in patients receiving multiple doses.
- Monitor BP q5min for the first 15–30 min or until stabilized, then hourly for balance of drug effect.
- Notify physician immediately if BP continues to fall 30 min or more after IV drug administration. Cause other than drug effect
is probable.
- Monitor pulse: Tachycardia has occurred immediately following IV; palpitation and bradycardia have also been reported.
- Report promptly any change in I&O ratio.
- Observe patient closely for S&S of CHF (see Appendix F).
- Monitor diabetics carefully for loss of glycemic control.
- Evaluate serum electrolyte levels at regular intervals, particularly in patients with impaired renal function; hypokalemia
potentiates hyperglycemic effect of diazoxide.
- Note: In contrast to IV diazoxide, oral administration usually does not produce marked effects on BP. However, do make periodic
measurements of BP and vital signs.
- Monitor S&S for up to 7 d for both oral and parenteral forms; essential because of long half-life of diazoxide.
Patient & Family Education
- Note: Drug may cause hyperglycemia and glycosuria in diabetic and diabetic-prone individuals. Closely monitor blood and urine glucose;
report any abnormalities to physician.
- Report palpitations, chest pain, dizziness, fainting, or severe headache.
- Note: Lanugo-type hirsutism occurs frequently, commonly in children and women. It is reversible with discontinuation of drug.
- Do not breast feed while taking this drug without consulting physician.
1%)
Canadian drug name; 
Prototype drug