Spironolactone and Hydrochlorothiazide

Diuretic · Aldosterone antagonist/Thiazide diuretic

Indications

Essential hypertension, oedema and ascites of congestive cardiac failure, cirrhosis of liver, nephrotic syndrome.

Dosage

Adults: 1 tab to 8 tab of 25 mg or 4 tab 50 mg daily. Children: 1.5-3 mg spironolactone per kg daily in divided doses.

Adverse Effects

Spironolactone: Gynaecomastia, Gl upset, rash, drowsiness, headache, confusion, malaise, benign breast neoplasm, blood dyscrasias, hepatic impairment, electrolyte disturbances, leg cramps, ataxia, dizziness, changes in libido, confusion, menstrual disorders, breast pain, skin reaction, acute renal failure, alterations in voice pitch. Hydrochlorothiazide: Anorexia, epigastric distress.

Risk Factor (Pregnancy/Lactation)

Pregnancy: Risk cannot be ruled out. Lactation: Contraindicated or not recommended. Contraindications: Spironolactone: Anuria, severe or progressive renal failure. Hyperkalaemia; Addison's disease, diabetes, diabetic nephropathy. Moderate to severe renal impairment in children. Hydrochlorothiazide: Anuria, renal decompensation. Precautions: Spironolactone: Renal or hepatic impairment. Long term use in young patients. Hyponatraemia, porphyria. Predisposition to acidosis. Monitor fluid, electrolytes and BUN. Hydrochlorothiazide: Avoid in severe renal disease. Gout, diabetes, patients with moderate to high cholesterol concentrations.

Interactions

Spironolactone: K+ supplements, K+ sparing diuretics, carbenoxolone, antihypertensives, ACE inhibitors, digoxin, angiotensin II inhibitors, NSAIDs, cyclosporin, fludrocortisone, lithium, anticoagulants, tacrolimus, noradrenaline, co-trimoxazole. Hydrochlorothiazide: Beta-blockers, ACE inhibitors, neuromuscular blocking agents, oral hypoglycaemics, NSAIDs.

Advice to Patient

Take with meals. Contact prescriber if there is worsening of condition or no improvement. Do not take foods rich in potassium and potassium supplements. Avoid driving, operating machinery or doing tasks that require alertness.

Pharmacokinetics

SPIRONOLACTONE: Duration: Tab: 2-3 days. Bioavailability: High-fat/-calorie meal increased the bioavailability of spironolactone approx. 90%. Metabolism: Rapid and extensive; hepatic. Half-life elimination: Tab: Approx. 1-4 hrs. Susp: 1-2 hrs. Time to peak, serum: Tab: 2.6-4.3 hrs. Susp: 0.5-1.5 hrs. Excretion: Urine and bile. HYDROCHLOROTHIAZIDE: Onset of action: Diuresis: Infants: 2-6 hrs. Adults: Approx. 2 hrs. Peak effect: 4-6 hrs. Duration: Infants: 8 hrs. Adults: 6-12 hrs. Absorption: Well absorbed, absorption is decreased in patients with CHF. Metabolism: Not metabolized. Bioavailability: 65%-75%. Half-life elimination: Approx. 6-15 hrs. Time to peak: Approx. 1-5 hrs. Excretion: Urine.

Compiled by Healify Pharmacy from published drug references. How we compile it →

Always consult a pharmacist or doctor.