Captopril

INDICATIONS & USAGE Captopril and hydrochlorothiazide tablets are indicated for the treatment of hypertension. The blood pressure lowering effects of captopril and thiazides are approximately additive. This fixed combination drug may be used as initial therapy or substituted for previously titrated doses of the individual components. When captopril and hydrochlorothiazide are given together it may not be necessary to administer captopril in divided doses to attain blood pressure control at trough (before the next dose). Also, with such a combination, a daily dose of 15 mg of hydrochlorothiazide may be adequate. Treatment may, therefore, be initiated with captopril and hydrochlorothiazide tablets 25 mg/15 mg once daily. Subsequent titration should be with additional doses of the components (captopril, hydrochlorothiazide) as single agents or as captopril and hydrochlorothiazide tablets 50 mg/15 mg, 25 mg/25 mg, or 50 mg/25 mg (see DOSAGE AND ADMINISTRATION ). In using captopril and hydrochlorothiazide, consideration should be given to the risk of neutropenia/agranulocytosis (see WARNINGS ). Captopril and hydrochlorothiazide may be used for patients with normal renal function, in whom the risk is relatively low. In patients with impaired renal function, particularly those with collagen vascular disease, captopril and hydrochlorothiazide should be reserved for hypertensives who have either developed unacceptable side effects on other drugs, or have failed to respond satisfactorily to other drug combinations. ACE inhibitors (for which adequate data are available) cause a higher rate of angioedema in black than in non-black patients (see WARNINGS: Captopril: Head and Neck Angioedema and Intestinal Angioedema ).

DOSAGE & ADMINISTRATION DOSAGE MUST BE INDIVIDUALIZED ACCORDING TO PATIENT'S RESPONSE. Captopril and hydrochlorothiazide tablets may be substituted for the previously titrated individual components. Alternatively, therapy may be instituted with a single tablet of captopril and hydrochlorothiazide 25 mg/15 mg taken once daily. For patients insufficiently responsive to the initial dose, additional captopril or hydrochlorothiazide may be added as individual components or by using captopril and hydrochlorothiazide tablets 50 mg/15 mg, 25 mg/25 mg or 50 mg/25 mg, or divided doses may be used. Because the full effect of a given dose may not be attained for 6 to 8 weeks, dosage adjustments should generally be made at 6 week intervals, unless the clinical situation demands more rapid adjustment. In general, daily doses of captopril should not exceed 150 mg and of hydrochlorothiazide should not exceed 50 mg. Captopril and hydrochlorothiazide tablets should be taken one hour before meals. Dosage Adjustment in Renal Impairment: Because captopril and hydrochlorothiazide are excreted primarily by the kidneys, excretion rates are reduced in patients with impaired renal function. These patients will take longer to reach steady-state captopril levels and will reach higher steady-state levels for a given daily dose than patients with normal renal function. Therefore, these patients may respond to smaller or less frequent doses of captopril and hydrochlorothiazide. After the desired therapeutic effect has been achieved, the dose intervals should be increased or the total daily dose reduced until the minimal effective dose is achieved. When concomitant diuretic therapy is required in patients with severe renal impairment, a loop diuretic (e.g., furosemide), rather than a thiazide diuretic is preferred for use with captopril; therefore, for patients with severe renal dysfunction the captopril-hydrochlorothiazide combination tablet is not usually recommended. (See WARNINGS: Captopril: Anaphylactoid Reactions During Membrane Exposure and PRECAUTIONS: Hemodialysis ).

ADVERSE REACTIONS Captopril : Reported incidences are based on clinical trials involving approximately 7000 patients. Renal : About one of 100 patients developed proteinuria (see WARNINGS ). Each of the following has been reported in approximately 1 to 2 of 1000 patients and are of uncertain relationship to drug use: renal insufficiency, renal failure, nephrotic syndrome, polyuria, oliguria, and urinary frequency. Hematologic : Neutropenia/agranulocytosis has occurred (see WARNINGS ). Cases of anemia, thrombocytopenia, and pancytopenia have been reported. Dermatologic : Rash, often with pruritus, and sometimes with fever, arthralgia, and eosinophilia, occurred in about 4 to 7 (depending on renal status and dose) of 100 patients, usually during the first four weeks of therapy. It is usually maculopapular, and rarely urticarial. The rash is usually mild and disappears within a few days of dosage reduction, short-term treatment with an antihistaminic agent, and/or discontinuing therapy; remission may occur even if captopril is continued. Pruritus, without rash, occurs in about 2 of 100 patients. Between 7 and 10 percent of patients with skin rash have shown eosinophilia and/or positive ANA titers. A reversible associated pemphigoid-like lesion, and photosensitivity, have also been reported. Flushing or pallor has been reported in 2 to 5 of 1000 patients. Cardiovascular : Hypotension may occur; see WARNINGS and PRECAUTIONS (Drug Interactions) for discussion of hypotension with captopril therapy. Tachycardia, chest pain, and palpitations have each been observed in approximately 1 of 100 patients. Angina pectoris, myocardial infarction, Raynaud’s syndrome, and congestive heart failure have each occurred in 2 to 3 of 1000 patients. Dysgeusia : Approximately 2 to 4 (depending on renal status and dose) of 100 patients developed a diminution or loss of taste perception. Taste impairment is reversible and usually self-limited (2 to 3 months) even with continued drug administration. Weight loss may be associated with the loss of taste. Angioedema : Angioedema involving the extremities, face, lips, mucous membranes, tongue, glottis or larynx has been reported in approximately one in 1000 patients. Angioedema involving the upper airways has caused fatal airway obstruction. (See WARNINGS: Captopril: Head and Neck Angioedema and Intestinal Angioedema and PRECAUTIONS: Information for Patients ). Cough : Cough has been reported in 0.5 to 2% of patients treated with captopril in clinical trials (see PRECAUTIONS: General: Captopril: Cough ). The following have been reported in about 0.5 to 2 percent of patients but did not appear at increased frequency compared to placebo or other treatments used in controlled trials: gastric irritation, abdominal pain, nausea, vomiting, diarrhea, anorexia, constipation, aphthous ulcers, peptic ulcer, dizziness, headache, malaise, fatigue, insomnia, dry mouth, dyspnea, alopecia, paresthesias. Other clinical adverse effects reported since the drug was marketed are listed below by body system. In this setting, an incidence or causal relationship cannot be accurately determined. Body as a Whole : Anaphylactoid reactions (see WARNINGS: Captopril: Anaphylactoid and Possibly Related Reactions and PRECAUTIONS: Hemodialysis ). General : asthenia, gynecomastia. Cardiovascular : cardiac arrest, cerebrovascular accident/insufficiency, rhythm disturbances, orthostatic hypotension, syncope. Dermatologic : bullous pemphigus, erythema multiforme (including Stevens-Johnson syndrome), exfoliative dermatitis. Gastrointestinal : pancreatitis, glossitis, dyspepsia. Hematologic : anemia, including aplastic and hemolytic. Hepatobiliary : jaundice, hepatitis, including rare cases of necrosis, cholestasis. Metabolic : symptomatic hyponatremia. Musculoskeletal : myalgia, myasthenia. Nervous/Psychiatric : ataxia, confusion, depression, nervousness, somnolence. Respiratory : bronchospasm, eosinophilic pneumonitis, rhinitis. Special Senses : blurred vision. Urogenital : impotence. As with other ACE inhibitors, a syndrome has been reported which may include: fever, myalgia, arthralgia, interstitial nephritis, vasculitis, rash or other dermatologic manifestations, eosinophilia and an elevated ESR. Fetal/Neonatal Morbidity and Mortality: See WARNINGS: Captopril: Fetal/Neonatal Morbidity and Mortality . Hydrochlorothiazide : Gastrointestinal System : anorexia, gastric irritation, nausea, vomiting, cramping, diarrhea, constipation, jaundice (intrahepatic cholestatic jaundice), pancreatitis, and sialadenitis. Central Nervous System : dizziness, vertigo, paresthesias, headache, and xanthopsia. Hematologic : leukopenia, agranulocytosis, thrombocytopenia, aplastic anemia, and hemolytic anemia. Cardiovascular : orthostatic hypotension. Hypersensitivity : purpura, photosensitivity, rash, urticaria, necrotizing angiitis (vasculitis; cutaneous vasculitis), fever, respiratory distress including pneumonitis, and anaphylactic reactions.

Drug Interactions: Captopril : Hypotension—Patients On Diuretic Therapy : Patients on diuretics and especially those in whom diuretic therapy was recently instituted, as well as those on severe dietary salt restrictions or dialysis, may occasionally experience a precipitous reduction of blood pressure usually within the first hour after receiving the initial dose of captopril. The possibility of hypotensive effects with captopril can be minimized by either discontinuing the diuretic or increasing the salt intake approximately one week prior to initiation of treatment with captopril or initiating therapy with small doses (6.25 or 12.5 mg). Alternatively, provide medical supervision for at least one hour after the initial dose. If hypotension occurs, the patient should be placed in a supine position and, if necessary, receive an intravenous infusion of normal saline. This transient hypotensive response is not a contraindication to further doses which can be given without difficulty once the blood pressure has increased after volume expansion. Agents Having Vasodilator Activity : Data on the effect of concomitant use of other vasodilators in patients receiving captopril for heart failure are not available; therefore, nitroglycerin or other nitrates (as used for management of angina) or other drugs having vasodilator activity should, if possible, be discontinued before starting captopril. If resumed during captopril therapy, such agents should be administered cautiously, and perhaps at lower dosage. Agents Causing Renin Release : Captopril’s effect will be augmented by antihypertensive agents that cause renin release. For example, diuretics (e.g., thiazides) may activate the renin-angiotensin-aldosterone system. Agents Affecting Sympathetic Activity : The sympathetic nervous system may be especially important in supporting blood pressure in patients receiving captopril alone or with diuretics. Therefore, agents affecting sympathetic activity (e.g., ganglionic blocking agents or adrenergic neuron blocking agents) should be used with caution. Beta-adrenergic blocking drugs add some further antihypertensive effect to captopril, but the overall response is less than additive. Agents Increasing Serum Potassium : Since captopril decreases aldosterone production, elevation of serum potassium may occur. Potassium-sparing diuretics such as spironolactone, triamterene, or amiloride, or potassium supplements, should be given only for documented hypokalemia, and then with caution, since they may lead to a significant increase of serum potassium. Salt substitutes containing potassium should also be used with caution. Gold : Nitritoid reactions (symptoms include facial flushing, nausea, vomiting and hypotension) have been reported rarely in patients on therapy with injectable gold (sodium aurothiomalate) and concomitant ACE inhibitor therapy including captopril and hydrochlorothiazide tablets. Inhibitors of Endogenous Prostaglandin Synthesis : It has been reported that indomethacin may reduce the antihypertensive effect of captopril, especially in cases of low renin hypertension. Other non-steroidal anti-inflammatory agents (e.g., aspirin) may also have this effect. Lithium : Increased serum lithium levels and symptoms of lithium toxicity have been reported in patients receiving concomitant lithium and ACE inhibitor therapy. These drugs should be coadministered with caution and frequent monitoring of serum lithium levels is recommended. If a diuretic is also used, it may increase the risk of lithium toxicity (see PRECAUTIONS: Drug Interactions: Hydrochlorothiazide: Lithium ). Hydrochlorothiazide : When administered concurrently the following drugs may interact with thiazide diuretics: Alcohol, Barbiturates, or Narcotics : potentiation of orthostatic hypotension may occur. Amphotericin B, Corticosteroids, or Corticotropin (ACTH) : may intensify electrolyte imbalance, particularly hypokalemia. Monitor potassium levels; use potassium replacements if necessary. Anticoagulants (Oral) : dosage adjustments of anticoagulant medication may be necessary since hydrochlorothiazide may decrease their effects. Antigout Medications : dosage adjustments of antigout medication may be necessary since hydrochlorothiazide may raise the level of blood uric acid. Other Antihypertensive Medications (e.g., Ganglionic or Peripheral Adrenergic Blocking Agents) : dosage adjustments may be necessary since hydrochlorothiazide may potentiate their effects. Antidiabetic Drugs (Oral Agents and Insulin): since thiazides may elevate blood glucose levels, dosage adjustments of antidiabetic agents may be necessary. Calcium Salts : Increased serum calcium levels due to decreased excretion may occur. If calcium must be prescribed, monitor serum calcium levels and adjust calcium dosage accordingly. Cardiac Glycosides : enhanced possibility of digitalis toxicity associated with hypokalemia. Monitor potassium levels (see PRECAUTIONS: Drug Interactions: Captopril ).