Captopril
Captopril (Capoten)
Captopril
( KAP-toe-prill)
Pregnancy Category: C (first trimester); D (second and third trimesters) Alti-Captopril Apo-Capto Capoten Gen-Captopril Med-Captopril Novo-Captoril Nu-Capto (Rx)

Classification: Antihypertensive, inhibitor of angiotensin synthesis

See Also: See also Angiotensin-Converting Enzyme Inhibitors .

Action/Kinetics: Onset: 60-90 min. Peak serum levels: 30-90 min; presence of food decreases absorption by 30%-40%. Plasma protein binding: 25%-30%. Time to peak effect: 60-90 min. Duration: 6-12 hr. t 1/2, normal renal function: 2 hr; t 1/2, impaired renal function: 3.5-32 hr. More than 95% of absorbed dose excreted in urine (40%-50% unchanged). Food decreases bioavailability of captopril by 30%-40%.

Uses: Antihypertensive, alone or in combination with other antihypertensive drugs, especially thiazide diuretics. In combination with diuretics and digitalis in treatment of CHF. To improve survival following MI in clinically stable clients with LV dysfunction manifested as an ejection fraction of 40% or less; to reduce the incidence of overt heart failure and subsequent hospitilization for CHF in these clients. Treatment of diabetic nephropathy (proteinuria > 500 mg/day) in those with type I insulin-dependent diabetes and retinopathy. Investigational: Rheumatoid arthritis, hypertensive crisis, neonatal and childhood hypertension, hypertension related to scleroderma renal crisis, diagnosis of anatomic renal artery stenosis, diagnosis of primary aldosteronism, Raynaud's syndrome, diagnosis of renovascular hypertension, enhance sensitivity and specificity of renal scintigraphy, idiopathic edema, and Bartter's syndrome.

Contraindications: Use with a history of angioedema related to previous use of ACE inhibitors.

Special Concerns: Use with caution in cases of impaired renal function and during lactation. Use in children only if other antihypertensive therapy has proven ineffective in controlling BP. May cause a profound drop in BP following the first dose or if used with diuretics.

Side Effects: Dermatologic: Rash (usually maculopapular) with pruritus and occasionally fever, eosinophilia, and arthralgia. Alopecia, erythema multiforme, photosensitivity, exfoliative dermatitis, Stevens-Johnson syndrome reversible pemphigoid-like lesions, bullous pemphigus, onycholysis, flushing, pallor, scalded mouth sensation. GI: N&V;, anorexia, constipation or diarrhea, gastric irritation, abdominal pain, dysgeusia, peptic ulcers, aphthous ulcers, dyspepsia, dry mouth, glossitis, pancreatitis. Hepatic: Jaundice, cholestasis, hepatitis. CNS: Headache, dizziness, insomnia, malaise, fatigue, paresthesias, confusion, depression, nervousness, ataxia, somnolence. CV: Hypotension, angina, MI Raynaud's phenomenon, chest pain, palpitations, tachycardia, CVA, CHF, cardiac arrest orthostatic hypotension, rhythm disturbances, cerebrovascular insufficiency. Renal: Renal insufficiency or failure, proteinuria, urinary frequency, oliguria, polyuria, nephrotic syndrome, interstitial nephritis. Respiratory: Bronchospasm cough, dyspnea, asthma, pulmonary embolism, pulmonary infarction. Hematologic: Agranulocytosis, neutropenia, thrombocytopenia, pancytopenia, aplastic or hemolytic anemia. Other: Decrease or loss of taste perception with weight loss (reversible), angioedema, asthenia, syncope, fever, myalgia, arthralgia, vasculitis, blurred vision, impotence, hyperkalemia, hyponatremia, myasthenia, gynecomastia, rhinitis, eosinophilic pneumonitis.

Laboratory Test Alterations: False + test for urine acetone.

Overdose Management: Symptoms: Hypotension with a systolic BP of <80 mm Hg a possibility. Treatment: Volume expansion with NSS (IV) is the treatment of choice to restore BP.

Additional Drug Interactions Probenecid increases blood levels of captopril due to decreased renal excretion.

How Supplied: Tablet: 12.5 mg, 25 mg, 50 mg, 100 mg

Dosage
?Tablets Hypertension.
Adults, initial: 25 mg b.i.d.-t.i.d. If unsatisfactory response after 1-2 weeks, increase to 50 mg b.i.d.-t.i.d.; if still unsatisfactory after another 1-2 weeks, thiazide diuretic should be added (e.g., hydrochlorothiazide, 25 mg/day). Dosage may be increased to 100-150 mg b.i.d.-t.i.d., not to exceed 450 mg/day.
Accelerated or malignant hypertension.
Stop current medication (except for the diuretic) and initiate captopril at a dose of 25 mg b.i.d.-t.i.d. The dose may be increased q 24 hr until a satisfactory response is obtained or the maximum dose reached. Furosemide may be indicated.
Heart failure.
Initial:25 mg t.i.d.; then, if necessary, increase dose to 50 mg t.i.d. and evaluate response; maintenance: 50-100 mg t.i.d., not to exceed 450 mg/day.
NOTE: For adults, an initial dose of 6.25-12.5 mg (0.15 mg/kg t.i.d. in children) should be given b.i.d.-t.i.d. to clients who are sodium- and water-depleted due to diuretics, who will continue to be on diuretic therapy, and who have renal impairment.
Left ventricular dysfunction after MI.
Therapy may be started as early as 3 days after the MI. Initial dose: 6.25 mg; then begin 12.5 mg t.i.d. and increase to 25 mg t.i.d. over the next several days. The target dose is 50 mg t.i.d. over the next several weeks. Other treatments for MI may be used concomitantly (e.g., aspirin, beta blockers, thrombolytic drugs).
Diabetic nephropathy.
25 mg t.i.d. for chronic use. Other antihypertensive drugs (e.g., beta blockers, centrally-acting drugs, diuretics, vasodilators) may be used with captopril if additional drug therapy is needed to reduce BP.
Hypertensive crisis.
Initial: 25 mg; then 100 mg 90-120 min later, 200-300 mg/day for 2-5 days (then adjust dose). Sublingual captopril, 25 mg, has also been used successfully.
Rheumatoid arthritis.
75-150 mg/day in divided doses.
Severe childhood hypertension.
Initial: 0.3 mg/kg titrated to 6 mg or less given in 2 to 3 divided doses.
NOTE: For all uses, doses should be reduced in clients with renal impairment.