Generic Name

Spironolactone

Precaution

Patient at risk of developing hyperkalaemia and acidosis, w/ DM. Renal and hepatic impairment. Elderly. Pregnancy and lactation. Patient Counselling This drug may cause dizziness and somnolence, if affected do not drive or operate machinery. Monitoring Parameters Monitor serum electrolytes periodically; BP, renal function. Lactation: Metabolite excreted into breast milk; discontinue breastfeeding or do not use drug

Indication

Oedema, Hirsutism, Hypertension, Hepatic cirrhosis w/ ascites and oedema, Hyperaldosteronism, Severe CHF, Hypokalaemia

Contra Indication

Anuria, hyperkalaemia, acute or progressive renal insufficiency. Addison's disease.

Dose

N/A

Side Effect

Drowsiness, dizziness, headache, lethargy, leg cramps, GI disturbances (e.g. diarrhoea, cramps), ataxia, mental confusion, rashes, pruritus, alopecia, hyponatraemia, electrolyte disturbances, gynaecomastia, hirsutism, menstrual irregularities, breast pain, deepening of the voice, impotence, leucopenia (including agranulocytosis), thrombocytopenia, transient elevation in BUN concentration. Rarely, breast enlargement. Potentially Fatal: Hyperkalaemia.

Pregnancy Category

Mode of Action

Spironolactone acts on the distal renal tubules as a competitive antagonist of aldosterone. It increases the excretion of sodium chloride and water while conserving potassium and hydrogen ions.

Interaction

Increased risk of hyperkalaemia w/ other K-sparing diuretics or K supplements, ACE inhibitors, angiotensin II receptor antagonists, trilostane, heparin, LMWH. Increased risk of nephrotoxicity w/ ciclosporin, NSAIDs. Increased risk of lithium toxicity. May reduce ulcer-healing properties of carbenoxolone. May increase serum level of digoxin. May reduce vascular response to norepinephrine. Concurrent use w/ colestyramine may cause hyperkalaemic metabolic acidosis. Potentiation of orthostatic hypotension may occur w/ barbiturates or narcotics. Potentially Fatal: May enhance hyperkalaemic effect w/ eplerenone. Increased risk of lithium toxicity when used concurrently.

Pregnancy Category Note

Pregnancy Based on mechanism of action and findings in animal studies, spironolactone may affect sex differentiation of the male during embryogenesis; rat embryofetal studies report feminization of male fetuses and endocrine dysfunction in females exposed to spironolactone in utero Limited available data did not demonstrate an association of major malformations or other adverse pregnancy outcomes with spironolactone; risks may occur to the mother and fetus associated with heart failure, cirrhosis, and poorly controlled hypertension during pregnancy Potential risk to the male fetus due to antiandrogenic properties of spironolactone; avoid spironolactone in pregnant women or advise a pregnant woman of the potential risk to a male fetus Disease-associated maternal and embryo/fetal risks Pregnant women with CHF are at increased risk for preterm birth; stroke volume and heart rate increase during pregnancy, increasing cardiac output, especially during the first trimester; closely monitor pregnant patients with CHF Pregnant women with symptomatic cirrhosis generally have poor outcomes (eg, hepatic failure, variceal hemorrhage, preterm delivery, fetal growth restriction, and maternal death); pregnant women with cirrhosis of the liver should be monitored and managed accordingly Hypertension in pregnancy increases the maternal risk for preeclampsia, gestational diabetes, premature delivery, and delivery complications (eg, need for cesarean delivery, postpartum hemorrhage); hypertension increases the fetal risk for intrauterine growth restriction and death Lactation Not present in breastmilk; however, limited data from a lactating woman at 17 days postpartum reports the presence of the active metabolite, canrenone, in human breast milk in low amounts that are expected to be clinically inconsequential; in this case, there were no adverse effects reported for the breastfed infant after short term exposure to spironolactone; however, long term effects on a breastfed infant are unknown; there are no data on spironolactone effects on milk production Consider the developmental and health benefits of breastfeeding along with the mother’s clinical need for the drug, and any potential adverse effects on the breastfed infant from the drug or from the underlying maternal condition

Adult Dose

Oral Oedema Adult: Initially, 100 mg daily, may adjust dose according to response up to 400 mg daily. Hepatic cirrhosis with ascites and oedema Adult: Depending on urinary Na/K ratio: If >1: Initially, 100 mg daily; if <1: Initially, 200-400 mg daily. Diagnosis of primary hyperaldosteronism Adult: Long test: 400 mg daily for 3-4 wk. Short test: 400 mg daily for 4 days. Preoperative management of hyperaldosteronism Adult: 100-400 mg daily. Long-term maintenance in the absence of surgery: Admin the lowest effective dose. Hypertension Adult: As monotherapy: Initially, 50-100 mg in 1-2 divided doses, may adjust dose after 2 wk. Severe congestive heart failure Adult: As adjunct: Initially, 25 mg once daily to max 50 mg daily. May reduce to 25 mg every other day if 25 mg once daily dose is not tolerated. Diuretic-induced hypokalaemia Adult: 25-100 mg daily. Hirsutism Women with hirsutism Adult: 50-200 mg qDay or divided q12hr Elderly: Initiate w/ the lowest dose then titrate upward if needed.

Child Dose

Oral Hepatic cirrhosis with ascites and oedema Child: Initially, 3 mg/kg given in divided doses, may adjust according to response. Diagnosis of primary hyperaldosteronism Child: Initially, 3 mg/kg given in divided doses, may adjust according to response. Preoperative management of hyperaldosteronism Child: Initially, 3 mg/kg given in divided doses, may adjust according to response. Severe congestive heart failure Child: Initially, 3 mg/kg given in divided doses, may adjust according to response.

Renal Dose

Renal impairment CrCl >50 mL/min/1.73 m²: 12.5-25 mg qDay; use maintenance dose of 25 mg qDay or q12hr after 4 weeks of treatment with potassium <5 mEq/L CrCl 30-49 mL/min/1.73 m²: 12.5 mg qDay or every other day; use maintenance dose of 12.5-25 mg qDay after 4 weeks of treatment with potassium <5 mEq/L CrCl <30 mL/min/1.73 m²: Avoid use

Administration

Should be taken with food.