Spironolactone (6 brand names, 2 dosage forms, 1 route)
Available dosage forms: TABLET, SUSPENSION.
Routes of administration: ORAL.
Brand Names
- ALDACTAZIDE
- ALDACTONE
- CAROSPIR
- SPIRONOLACTONE
- SPIRONOLACTONE AND HYDROCHLOROTHIAZIDE
- SPIRONOLACTONE W/ HYDROCHLOROTHIAZIDE
Contraindications
Spironolactone is contraindicated in the patients with: Hyperkalemia Addison’s disease Concomitant use of eplerenone
Adverse Reactions
The following clinically significant adverse reactions are described elsewhere in the labeling: Hyperkalemia [see Warnings and Precautions (5.1)] Hypotension and Worsening Renal Function [see Warnings and Precautions (5.2)] Electrolyte and Metabolic Abnormalities [see Warnings and Precautions (5.3)] Gynecomastia [see Warnings and Precautions (5.4)] Impaired neurological function/ coma in patients with hepatic impairment, cirrhosis and ascites [see Use in Specific Populations (8.7)] The following adverse reactions associated with the use of spironolactone were identified in clinical trials or postmarketing reports. Because these reactions were reported voluntarily from a population of uncertain size, it is not always possible to estimate their frequency, reliably, or to establish a causal relationship to drug exposure. Digestive:Gastric bleeding, ulceration, gastritis, diarrhea and cramping, nausea, vomiting. Reproductive:Decreased libido, inability to achieve or maintain erection, irregular menses or amenorrhea, postmenopausal bleeding, breast and nipple pain. Hematologic:Leukopenia (including agranulocytosis), thrombocytopenia. Hypersensitivity:Fever, urticaria, maculopapular or erythematous cutaneous eruptions, anaphylactic reactions, vasculitis. Metabolism:Hyperkalemia, electrolyte disturbances [see Warnings and Precautions (5.1, 5.3)] , hyponatremia, hypovolemia. Musculoskeletal: Leg cramps. Nervous system/psychiatric:Lethargy, mental confusion, ataxia, dizziness, headache, drowsiness. Liver/biliary:A very few cases of mixed cholestatic/hepatocellular toxicity, with one reported fatality, have been reported with spironolactone administration. Renal:Renal dysfunction (including renal failure). Skin:Stevens-Johnson Syndrome (SJS), toxic epidermal necrolysis (TEN), drug rash with eosinophilia and systemic symptoms (DRESS), alopecia, pruritis.
Mechanism of Action
Spironolactone and its active metabolites are specific pharmacologic antagonists of aldosterone, acting primarily through competitive binding of receptors at the aldosterone-dependent sodium-potassium exchange site in the distal convoluted renal tubule. Spironolactone causes increased amounts of sodium and water to be excreted, while potassium is retained. Spironolactone acts both as a diuretic and as an antihypertensive drug by this mechanism. It may be given alone or with other diuretic agents that act more proximally in the renal tubule.
Overdosage
The oral LD 50of spironolactone is greater than 1000 mg/kg in mice, rats, and rabbits. Acute overdosage of spironolactone may be manifested by drowsiness, mental confusion, maculopapular or erythematous rash, nausea, vomiting, dizziness, or diarrhea. Rarely, instances of hyponatremia, hyperkalemia, or hepatic coma may occur in patients with severe liver disease, but these are unlikely due to acute overdosage. Hyperkalemia may occur, especially in patients with impaired renal function. Treatment:Induce vomiting or evacuate the stomach by lavage. There is no specific antidote. Treatment is supportive to maintain hydration, electrolyte balance, and vital functions. Patients who have renal impairment may develop hyperkalemia. In such cases, discontinue spironolactone.