Spironolactone is approved by the FDA for the treatment of various conditions, including ascites, peripheral edema associated with portal hypertension, hyperaldosteronism, nephrotic syndrome, primary hyperaldosteronism, and hypertension.
Additionally, it is utilized off-label for managing androgenetic alopecia (AGA) or male and female pattern hair loss.
Mechanism of Action
Spironolactone functions as a specific pharmacological opponent to aldosterone, mainly by competitively binding to receptors at the sodium-potassium exchange site influenced by aldosterone in the distal convoluted renal tubule. Through this action, spironolactone leads to increased elimination of sodium and water while retaining potassium. It has a dual action as a diuretic and antihypertensive agent based on this mechanism.
Who should not use spironolactone?
The following conditions may preclude the usage of spironolactone:
- Individuals with an allergy to spironolactone or any other component of this medicine.
- Those allergic to drugs, foods, or substances related to spironolactone.
- Spironolactone is contraindicated for patients with anuria, acute renal insufficiency, significant impairment of renal excretory function, or hyperkalemia.
- Pediatric use: Safety and effectiveness in pediatric patients have not been established
Furthermore, it is essential to inform your doctor if you have or have had:
- Any other health problems or are taking any medications, including prescription, over-the-counter, natural products, and vitamins.
- Issues like diabetes, kidney disease, severe illness, or if you are an older adult.
- If you are on a low-salt or salt-free diet.
- If you are pregnant, plan on getting pregnant, or if you are breastfeeding.
What should I tell a provider before starting spironolactone?
Ensure you disclose your entire medical history to your healthcare provider. Be aware that withholding or providing inaccurate health and medical history to obtain treatment can have serious consequences, potentially including death.
- This medicine may raise potassium levels in the blood, with a higher risk in people with diabetes, kidney disease, severe illness, and in older adults.
- Blood work to monitor kidney function and potassium levels in the blood is not routinely recommended for healthy patients under age 46 with no comorbidities.
- Spironolactone is pregnancy category C, indicating that its safety in pregnant women has not been fully established. It should be avoided by women who are pregnant, planning pregnancy, or breastfeeding unless deemed essential by a physician.
- Discuss with your doctor and pharmacist about all your drugs and health problems, as spironolactone may interact with various medications.
- When used alongside ACE inhibitors, spironolactone might lead to severe hyperkalemia.
- Alcohol, barbiturates, or narcotics taken along with spironolactone may intensify orthostatic hypotension.
- Corticosteroids and ACTH combined with spironolactone might intensify electrolyte depletion, particularly hypokalemia.
- Spironolactone reduces the body's response to norepinephrine, which should be considered during anesthesia.
- Taking skeletal muscle relaxants concurrently with spironolactone might heighten the muscle relaxant's effects.
- Avoid combining lithium with diuretics like spironolactone as it can increase the risk of lithium toxicity.
- NSAIDs, when used with spironolactone, might reduce the diuretic effect; extreme caution is advised, especially with potassium-sparing diuretics, to prevent severe hyperkalemia.
- Spironolactone could increase digoxin levels, leading to potential digitalis toxicity. Dosages may need adjustment when used together, requiring careful monitoring to avoid issues with digoxin levels.
- Spironolactone or its metabolites might interfere with digoxin radioimmunoassays, affecting the accuracy of digoxin test results.
How should I use spironolactone?
- Topical spironolactone should be applied to the affected areas of the scalp as directed by your provider. The topical formulation is meant for external use only and should not be ingested or applied to other body parts. Wash your hands thoroughly after application.
- Oral spironolactone can be taken with or without meals. You should take oral spironolactone exactly as prescribed and should not change your dosing regimen without discussing it with your provider first.
What side effects should I be aware of with spironolactone?
Adverse reactions reported with oral spironolactone include:
- Digestive: Gastric bleeding, ulceration, gastritis, diarrhea, cramping, nausea, and vomiting.
- Endocrine: Gynecomastia, erectile dysfunction, irregular menses, amenorrhea, postmenopausal bleeding. Breast carcinoma has been reported in patients using spironolactone, although a direct cause-effect relationship hasn't been established.
- Hematologic: Agranulocytosis.
- Hypersensitivity: Fever, urticaria, skin eruptions, anaphylactic reactions, vasculitis.
- Metabolism: Hyperkalemia.
- Nervous system/psychiatric: Mental confusion, ataxia, headache, drowsiness, lethargy.
- Liver/biliary: Rare cases of mixed cholestatic/hepatocellular toxicity, with occasional fatalities.
- Renal: Renal dysfunction, including renal failure.
You or a caregiver should carefully monitor for these side effects, especially in the beginning of treatment and with dose changes. If you experience severe symptoms or are having a medical emergency, call 911 or seek immediate medical attention.
The above does not encompass all potential side effects, medication interactions, or studies related to spironolactone. Unreported or yet undiscovered side effects might exist. Please review the FDA prescribing information and the Prescriber’s Digital Reference (PDR) for a comprehensive overview of spironolactone. https://www.accessdata.fda.gov/drugsatfda_docs/label/2018/012151s075lbl.pdf