spironolactone

Absorption: >90% absorbed. Oral suspension results in 15–37% higher serum concentrations compared to tablets. Bioavailability ↑ with food.

Distribution: Crosses the placenta; enters breast milk.

Protein Binding: >90%.

Metabolism/Excretion: Converted by the liver to its active diuretic compound (canrenone). Primarily excreted in the urine.

Half-Life: Spironolactone: 78–84 min; Canrenone: 13–24 hr.

Time/Action Profile ⬆ ⬇

(diuretic effect)

ROUTE	ONSET	PEAK	DURATION
PO	unknown	1–3 hr	2–3 days‡

‡Multiple doses.

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Hypersensitivity;
Severe renal impairment (CCr <30 mL/min); SCr >2.5 mg/dL (for patients with HF);
Hyperkalemia;
Addison's disease;
Concurrent use of eplerenone;
OB: Pregnancy.

Use Cautiously in:

Hepatic impairment;
Diabetes mellitus (↑ risk of hyperkalemia);
Lactation: Use while breastfeeding only if potential maternal benefit justifies potential risk to infant;
Pedi: Safety and effectiveness not established in children;
Geri: risk of hyperkalemia in older adults.

Adv. Reactions/Side Effects ⬆ ⬇

CV: arrhythmias

Derm: alopecia, DRUG RASH WITH EOSINOPHILIA AND SYSTEMIC SYMPTOMS (DRESS), pruritus, STEVENS-JOHNSON SYNDROME (SJS), TOXIC EPIDERMAL NECROLYSIS (TEN)

Endo: amenorrhea, breast tenderness, deepening of voice, gynecomastia (in males), ↑hair growth (in females), sexual dysfunction

F and E: hyperkalemia, hyponatremia, hyperchloremic metabolic acidosis

GI: GI irritation

GU: erectile dysfunction, dysuria

Hemat: agranulocytosis, thrombocytopenia

MS: muscle cramps

Neuro: dizziness, headache, sedation

Misc: HYPERSENSITIVITY REACTIONS(INCLUDING ANAPHYLAXIS)

Interactions ⬆ ⬇

Drug-drug:

Use with eplerenone↑ risk of hyperkalemia; concurrent use contraindicated.
↑risk of hypotension with acute ingestion of alcohol, other antihypertensive agents, or nitrates.
Use with ACE inhibitors, NSAIDs, potassium supplements, angiotensin II receptor antagonists, potassium-sparing diuretics, angiotensin converting enzyme inhibitors, or cyclosporine↑ risk of hyperkalemia.
↓lithium excretion.
Antihypertensive and diuretic effectiveness may be ↓ by NSAIDs.
May ↑ levels and risk of toxicity of digoxin; monitor levels closely.
May ↑ levels and risk of toxicity of CYP2C8 substrates, including repaglinide.
May ↑ levels and risk of toxicity of CYP3A4/5 substrates, including midazolam, sirolimus, or tacrolimus.
↓hypoprothrombinemic effect of oral anticoagulants.
Cholestyramine may ↑ risk of hyperkalemic metabolic acidosis.
May ↑ prostate-specific antigen levels in patients receiving abiraterone; concurrent use not recommended.

Route/Dosage ⬆ ⬇

Oral suspension is not therapeutically equivalents to tablets. If patient requires a dose >100 mg, use tablets, NOT suspension. Suspension doses >100 mg may result in higher than expected spironolactone concentrations.

Heart Failure

PO (Adults ): Serum potassium ≤5 mEq/L and eGFR>50 mL/min/1.73 m²: Tablet: 25 mg once daily; may then ↑ to 50 mg once daily; if patient develops hyperkalemia with 25 mg once daily, ↓ dose to 25 mg every other day. Suspension: 20 mg once daily; may then ↑ to 37.5 mg once daily; if patient develops hyperkalemia with 20 mg once daily, ↓ dose to 20 mg every other day. Serum potassium ≤5 mEq/L and eGFR 30–50 mL/min/1.73 m²: Tablets: 25 mg every other day. Suspension: 10 mg once daily.

Hypertension

PO (Adults ): Tablets: 25–100 mg/day as a single dose or 2 divided doses; may titrate dose every 2 wk (max dose = 100 mg/day). Suspension: 20–75 mg/day as a single dose or 2 divided doses; may titrate dose every 2 wk (max dose = 75 mg/day).

Edema

PO (Adults ): Tablets: 25–200 mg/day as a single dose or 2 divided doses. Suspension: 75 mg/day as a single dose or 2 divided doses.

Primary Hyperaldosteronism

PO (Adults ): 100–400 mg/day.

Acne (off-label use)

PO (Adults ): 50–200 mg once daily.

Hormone Therapy for Transgender Females (off-label use)

PO (Adults ): 25 mg once or twice daily in combination with other appropriate agents. Increase at 1-wk intervals based on serum testosterone levels and tolerability to a usual dose of 50–150 mg twice daily (max dose = 200 mg twice daily).

Availability ⬆ ⬇

(Generic available)

Tablets: 25 mg; 50 mg; 100 mg
Oral suspensionbanana flavor: 25 mg/5 mL
In combination with: hydrochlorothiazide.

Assessment ⬆ ⬇

Monitor intake and output ratios and daily weight during therapy.
If medication is given as an adjunct to antihypertensive therapy, evaluate BP before administering and periodically during therapy.
Assess patient frequently for development of hyperkalemia (fatigue, muscle weakness, paresthesia, confusion, dyspnea, cardiac arrhythmias). Patients who have diabetes mellitus or kidney disease and elderly patients are at increased risk of developing these symptoms.
Periodic ECGs may be recommended in patients receiving prolonged therapy.
Assess patient for skin rash frequently during therapy. Discontinue diuretic at first sign of rash; may be life-threatening. SJS or TEN may develop. Treat symptomatically; may recur once treatment is stopped.
Monitor for signs and symptoms of DRESS (fever, rash, lymphadenopathy, facial swelling) periodically during therapy. Discontinue therapy if symptoms occur.

Lab Test Considerations:

Evaluate serum potassium levels prior to therapy, within 1 wk of starting therapy or dose increase, and routinely during therapy. If hyperkalemia occurs, decrease dose or discontinue therapy and treat hyperkalemia.
- Monitor BUN, serum creatinine, and electrolytes prior to and periodically during therapy. May cause ↑ serum magnesium, uric acid, BUN, creatinine, potassium, plasma renin activity, and urinary calcium excretion levels. May also cause ↓ sodium levels.
- Discontinue potassium-sparing diuretics 3 days prior to a glucose tolerance test because of risk of severe hyperkalemia.
- May cause false ↑ of plasma cortisol concentrations. Spironolactone should be withdrawn 4–7 days before test.

Implementation ⬆ ⬇

Carospir is not therapeutically equivalent to Aldactone; do not interchange.
PO: Administer in am to avoid interrupting sleep pattern.
- Administer with food or milk to minimize gastric irritation and to increase bioavailability.
- Oral suspension does not require dilution.

Patient/Family Teaching ⬆ ⬇

Emphasize the importance of continuing to take this medication, even if feeling well. Instruct patient to take medication at the same time each day. Take missed doses as soon as remembered unless almost time for next dose. Do not double doses.
- Caution patient to avoid salt substitutes and foods that contain high levels of potassium unless prescribed by health care professional.
- May cause dizziness. Caution patient to avoid driving or other activities requiring alertness until response to medication is known.
- Instruct patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and consult health care professional before taking any new medications, especially OTC decongestants, cough or cold preparations, or appetite suppressants due to potential for increased BP.
- Instruct patient to notify health care professional of medication regimen prior to treatment or surgery.
- Advise patient to notify health care professional if rash, muscle weakness or cramps, fatigue, or severe nausea, vomiting, or diarrhea occurs.
- Inform male patients that spironolactone may cause gynecomastia; may require dose decrease. Usually reversible.
- Advise females of reproductive potential to notify health care professional if pregnancy is planned or suspected or if breastfeeding.
- Emphasize the need for follow-up exams to monitor progress.
Hypertension: Reinforce need to continue additional therapies for hypertension (weight loss, restricted sodium intake, stress reduction, moderation of alcohol intake, regular exercise, and cessation of smoking). Medication helps control but does not cure hypertension.
- Teach patient and family the correct technique for checking BP weekly.

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Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇

Action ⬆ ⬇

Pharmacokinetics ⬆ ⬇