Product Details

Captopril

A to Z Drug Facts

Captopril

Action
Indications
Contraindications
Route/Dosage
Interactions
Lab Test Interferences
Adverse Reactions
PrecautionsPatient Care Considerations
Administration/Storage
Assessment/Interventions
Patient/Family Education

(KAP-toe-prill)Capoten, APO-Capto, Nova-Captopril, Nu-CaptoClass: Antihypertensive/ACE inhibitor

 Action Competitively inhibits angiotensin I-converting enzyme, preventing conversion of angiotensin I to angiotension II, a potent vasoconstrictor that also stimulates aldosterone secretion. Results in decreased BP, potassium retention, and reduced sodium reabsorption.

 Indications Treatment of hypertension, CHF in patients unresponsive to or uncontrolled by conventional therapy, left ventricular dysfunction after MI, diabetic nephropathy. Unlabeled use(s): Treatment of hypertensive crisis, neonatal and childhood hypertension; rheumatoid arthritis; diagnosis of anatomic renal artery stenosis and primary aldosteronism; treatment of hypertension related to scleroderma renal crisis and Takayasu's disease; idiopathic edema; Bartter's and Raynaud's syndrome; asymptomatic left ventricular dysfunction after MI.

 Contraindications Hypersensitivity to ACE inhibitors.

 Route/Dosage

Hypertension

ADULTS: Initial dose: PO 25 mg bid to tid; then gradually increase q 1 to 2 wk if satisfactory effect is not achieved. Usual dose: 25 to 150 mg bid to tid. Usual dose does not exceed 50 mg 3 times daily. Max daily dose is 450 mg.

Severe Hypertension

CHILDREN: PO 0.01–0.5 mg/kg/day.

Heart Failure

ADULTS: Initial dose: PO 6.25 to 12.5 mg tid; then titrate to usual daily dosage within next several days. Genereally to be used in conjunction with a diuretic and digitalis.

Left Ventricular Dysfunction after MI

ADULTS: PO 6.25 mg 3 days after MI; then 12.5 mg tid and 25 mg tid for next several days. Target dose: 50 mg tid over next several weeks.

Diabetic Nephropathy

ADULTS: PO 25 mg tid.

 Interactions

Allopurinol: Greater risk of hypersensitivity with coadministration. Antacids: May decrease bioavailability of captopril. Capsaicin: Cough may be exacerbated. Digoxin: Increased digoxin levels. Food: Reduces bioavailability of captopril. Indomethacin: Hypotensive effects may be reduced, especially in low-renin or volume-dependent hypertensive patients. Lithium: Increased lithium levels and symptoms of lithium toxicity may occur. Phenothiazines: May increase effect of captopril. Potassium preparations, potassium-sparing diuretics: May increase serum potassium levels. Probenecid: Increased captopril blood levels and decreased total clearance.

 Lab Test Interferences False-positive urine acetone test may occur.

 Adverse Reactions

CV: Chest pain; palpitations; tachycardia; orthostatic hypotension. CNS: Headache; sleep disturbances; paresthesias; dizziness; fatigue; malaise. DERM: Rash; pruritus; alopecia. EENT: Rhinitis. GI: Nausea; abdominal pain; vomiting; gastric irritation; aphthous ulcers; peptic ulcer; jaundice; cholestasis; diarrhea; dysgeusia; anorexia; constipation; dry mouth. GU: Oliguria; proteinuria. HEPA: Elevated liver enzymes and serum bilirubin. HEMA: Neutropenia; agranulocytosis; thrombocytopenia; pancytopenia. META: Hyperkalemia; hyponatremia; elevated uric acid and blood glucose. RESP: Chronic dry cough: dyspnea; eosinophilic pneumonitis. OTHER: Gynecomastia; myasthenia.

 Precautions

Pregnancy: Category D (second and third trimester); category C (first trimester). ACE inhibitors can cause injury or death to fetus if used during second or third trimester. When pregnancy is detected, discontinue ACE inhibitors as soon as possible. Lactation: Excreted in breast milk. Children: Safety and efficacy not established. Angioedema: Use with extreme caution in patients with hereditary angioedema. Hypotension/first-dose effect: Significant decreases in BP may occur after first dose, especially in patients with severe salt or volume depletion or those with CHF. Neutropenia and agranulocytosis: Risk appears greater with renal dysfunction, CHF. Proteinuria: May occur, especially in patients with prior renal disease or those receiving high doses of drug (> 150 mg/day); generally resolves within 6 mo. Renal impairment: Reserve use for hypertensive patients who have either developed unacceptable side effects on other drugs, or have failed to respond satisfactorily to drug combinations. Reduce dosage. In renal insufficiency, stable elevations in BUN and serum creatinine may occur because of inadequate renal perfusion.

PATIENT CARE CONSIDERATIONS

 

 Administration/Storage

• Administer either 1 hr before or 2 hr after meals because food reduces absorption of drug.
• If tablets are used to prepare a solution, store in glass bottles. Syrup is stable 7 days refrigerated or at room temperature. Solution with distilled water is stable 7 days at room temperature or 14 days refrigerated. Solution with distilled water plus sodium ascorbate is stable 14 days at room temperature or 56 days refrigerated.
• If patient is taking antacids, separate administration of captopril and antacid by 1 to 2 hr.
• Store at room temperature and protect from light.

 Assessment/Interventions

• Obtain patient history, including drug history and any known allergies. Note any cardiac disease or concurrent dialysis therapy.
• Determine whether patient is taking antihypertensives, diuretics (especially potassium-sparing), salt substitutes, or potassium replacement drugs.
• Monitor BP closely for at least 2 hr after initial dose and during first 2 wk of therapy. Observe for sudden exaggerated hypotensive response.
• Monitor BP and pulse throughout therapy.
• Monitor blood studies, electrolytes, and renal and liver function throughout therapy.
• Assess urine for protein during first 6 mo of therapy and periodically thereafter.
• If patient is undergoing diuretic therapy, monitor weight and assess for resolution of fluid overload.
• Report increased serum potassium and decreased sodium ions to physician.
• If signs of hyperkalemia or hyponatremia occur, report to physician.

OVERDOSAGE: SIGNS & SYMPTOMS Hypotension

 Patient/Family Education

• Teach patient or family member how to monitor and record BP daily (or as indicated).
• Instruct patient to monitor weight daily at consistent time and to notify physician of 5 lb weight fluctuation.
• If patient is overweight, advise to enroll in medically supervised weight management program.
• Counsel patient to adhere to low-sodium diet and to check with physician before using any salt substitute.
• Caution patient to avoid smoking and alcohol intake.
• Emphasize importance of daily physical exercise routine.
• Advise patient to be alert for symptoms of hypotension, especially in early therapy. Stress importance of avoiding rapid posture changes and dangling feet before getting out of bed.
• Explain effect of captopril on water retention and lowering BP. Tell patient to expect increased urine output.
• Explain that if patient becomes dehydrated (eg, from flu or excessive sweating), hypotensive effect of drug may be increased and dizziness may be noted. Advise patient to contact physician if this occurs.
• Tell patient that chronic cough is common side effect and to notify physician if this effect occurs.
• Instruct patient to report these symptoms to physician: Vomiting, diarrhea; swelling of eyes, face, lips, tongue or throat; difficulty breathing, speaking, or swallowing.
• Emphasize importance of complying with dosage schedule. Caution patient not to discontinue taking drug and not to take otc medications without consulting physician.

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Copyright © 2003 Facts and Comparisons
David S. Tatro
A to Z Drug Facts