Composition
Each tablet contains captopril 25 mg.
Properties
Captopril (Hypopress®) is a specific competitive inhibitor of angiotensin converting enzyme, ACE, the enzyme responsible for the conversion of angiotensin I to angiotensin II. This results in:
- Decrease in the potent endogenous vasoconstrictor substance angiotensin II.
- Decrease in aldosterone secretion from the adrenal cortex and, as a result, sodium and fluid loss along with slight increase in serum potassium may occur.
- Interference with the degradation of the vasodepressor peptide bradykinin.
Pharmacokinetics
After oral administration of captopril (Hypopress®), rapid absorption occurs with peak blood levels at about one hour. It should be given one hour before meals as the presence of food in the gastrointestinal tract reduces its absorption.
Half life of the unchanged drug is approximately 2 hours, however, the therapeutic effects of the drug persist for a longer period of time than does demonstrable inhibition of serum ACE.
In a 24 hour period, over 95% of the absorbed dose is eliminated in urine, 40-50 % is unchanged and most of the remainder conjugates with endogenous thiol compounds (disulfide dimmer and cysteine disulfide). Captopril (Hypopress®) is removable by hemodialysis.
Pharmacodynamics
Captopril (Hypopress®) administration in hypertensive patients results in the reduction of peripheral arterial resistance with either no change or an increase in cardiac output with consequent increase in renal blood flow.
The blood pressure reductions are usually maximal 60 to 90 minutes after oral administration, and the duration of effect is dose-related. The maximal therapeutic effects are achieved several weeks after administration.
In patients with heart failure, captopril (Hypopress®) administration results in a significant decrease in systemic vascular resistance and blood pressure (afterload), pulmonary capillary wedge pressure (preload), pulmonary vascular resistance and an increase in cardiac output and exercise tolerance.
Indications
- Hypertension: Hypopress® is effective alone and in combination with other antihypertensive agents.
- Heart failure: Hypopress® is indicated in the treatment of congestive heart failure.
- Left-ventricular Dysfunction after myocardial infarction.
Contraindications
- Hypersensitivity to captopril or any other angiotensin converting enzyme inhibitor.
- Pregnant women, as captopril crosses the placental barrier.
Precautions
- Impaired renal function and bilateral renal artery stenosis
- Hyperkalemia, in patients with renal insufficiency and those using potassium sparing diuretics, potassium supplements or potassium containing salt substitutes
- Patients with aortic stenosis
- Nursing mothers, a decision should be made whether to discontinue nursing or to discontinue captopril
- In patients receiving drugs known to cause neutropenia, e.g. immunosuppressants, procainamide, allopurinol
Adverse Effects
Captopril is generally well tolerated but occasionally minor side effects may occur, e.g. headache, dizziness, skin rash, gastric upset, taste alteration, cough.
Dosage
Hypopress®(captopril) should be taken one hour before meals and dosage must be individualized.
Adult Dosage for Hypertension
The usual initial daily dose of Hypopress® (captopril) is 25 mg 2-3 times, if satisfactory reduction of blood pressure has not been achieved after one to two weeks, the dose may be increased to 50 mg 2-3 times daily.
Hypopress® dosage in hypertension usually does not exceed 50 mg 3 times daily. In severe hypertension further blood pressure reduction is required, therefore, the dose may be increased to 100-150 mg 2-3 times daily (a maximum daily dose of captopril 450 mg should not be exceeded).
Adult dosage for Heart failure and left ventricular dysfunction after myocardial infarction
The usual initial daily dose is 25 mg 3 times. In patients with either normal or low blood pressure the starting dose is 12.5 mg (½ tablet) 2-3 times daily; this dose may minimize the magnitude and duration of captopril hypotensive effect.
Children dosage
The usual initial dose of Hypopress® (captopril) is 0.3 mg/kg to be increased under strict medical supervision to a maximum daily dose of 6 mg/kg divided into 3 doses.
Dosage in renal impairment
In renal impairment the daily dose should be reduced or the dose interval increased.
How Supplied
Strips of 10 tablets in packs of 1 strip.
Keep all medicaments out of reach of children
Product of: AMOUN PHARMACEUTICAL CO. El-Obour City, Cairo, Egypt. ATC Code: C09AA01