Captopril Pharmacology

Captopril

About Captopril
A specific competitive Angiotensin-Converting Enzyme (ACE) Inhibitor, Antihypertensive.
Mechanism of Action of Captopril
It is an angiotensin converting enzyme inhibitor prevents the conversion of angiotensin-1 to angiotensin-2 and abolishes the pressor actions of angiotensin. It decreases aldosterone secretion, sodium and water retention, and total peripheral resistance, leads to fall in BP. The arterioles dilate and the compliance of larger arteries is increased. Both systolic and diastolic BP is lowered. It has no effect on cardiac output and cardiovascular reflexes. And there is little dilatation of capacitance vessels; so postural hypotension is not a problem. The drug does not compromise renal, cerebral, and coronary blood flow. BP lowering depending up on sodium status and renin angiotensin activity. So greater fall in BP occurs in Reno vascular accelerated and malignant hypertension. The drug also increases plasma kinin levels and potentiate the hypotensive action of exogenously administered bradykinin. It is used for treatment of systolic heart failure, because it improves symptoms, decrease mortality and reduce ventricular hypertrophy. It reduces both preload and after load and thus increasing cardiac out put in patients with heart failure.
Pharmacokinets of Captopril
Absorption: Well absorbed orally, food reduces absorption. Distribution: Widely distributed, but poor brain penetration. Metabolism: About 50% is metabolized in liver, Excretion: Excreted mainly through urine and a small amount is excreted through faeces.
Onset of Action for Captopril
15 minutes
Duration of Action for Captopril
6 to 12 hours
Half Life of Captopril
2 to 3 hours
Side Effects of Captopril
1.Cough
2.Angioedema
3.Hypotension
4.Hyperkalemia
5.Rashes
6.Urticaria
7.Swelling of lips, mouth, nose, and larynx
8.Dysguesia
9.Fetopathic in later half of pregnancy
10.Headache
11.Dizziness
12.Nausea
13.Granulocytopenia(rare)
14.Proteinuria(rare)
15.Acute renal failure is precipitated in renal artery stenosis
16.Transient increase in liver enzymes.
Contra-indications of Captopril
1.Hypersensitivity to the drug
2.Renal impairment
3.Aortic stenosis.
Special Precautions while taking Captopril
1.Renal impairment
2.Severe autoimmune diseases
3.Sodium depletion should be corrected before starting therapy
4.Anaesthesia
5.Use cautiously along with drug that affects WBC counts or immune response
Pregnancy Related Information
Contraindicated
Old Age Related Information
Use with caution
Breast Feeding Related Information
Use with caution
Children Related Information
Use with caution
Indications for Captopril
1.Hypertension
2.Heart failure
3.Left ventricular dysfunction after myocardial infarction
4.Diabetic nephropathy
Interactions for Captopril
Antacids: Decrease efficacy of Captopril.
Indomethacin: Reduces hypotensive effect.
Digoxin: Increases plasma digoxin levels.
Potassium preparations & Postassium sparing diuretics: Hyperkalaemia and increased risk of renal failure.
Lithium: Toxicity due to increased serum concentration of Lithium.
Immunosuppressive Drugs: Increased risk of bone marrow depression.
Antidepressants, Diuretics, b-Blockers, Phenothiazines: Enhance hypotensive effect.
Morphine: Enhanced analgesic effect and respiratory depression.
Typical Dosage for Captopril
25mg 12th hourly or 8th hourly. Increases the dose after 1 to 2 weeks to 50mg 8th hourly. If patient`s response is inadequate, a diuretic may be added. Dosage may further increases to 100mg 8th hourly based on patient`s response if required.
Maximum dose: 450mg/day
Children:0.15mg/kg/day once daily or in 3 to 6 divided doses.
Heart failure: 25mg 8th hourly. Increases to 25 to 50mg 8th hourly if required. In patients on diuretic therapy starts the therapy with an initial dosage of 6.25 to 12.5 mg 8th hourly.
Left ventricular dysfunction after myocardial infarction: Give 6.25mg orally as a single dose 3days after myocardial infarction. Then 12.5mg 8th hourly and gradually increases
to 25mg or50mg 8th hourly.
Diabetic nephropathy: 25mg 8th hourly.
Schedule of Captopril
H
Storage Requirements for Captopril
Store at controlled room temperature at a range of 15 to 30 degree C.
Effects of Missed Dosage of Captopril
Take the missed dose as soon as noticed and if it is the time for next dose then skip the missed dose. Continue the regular schedule. Do not double the dose.
Effects of Overdose of Captopril
Treatment is supportive and symptomatic. To remove drug from the body perform induced emesis and gastric lavage. Administer activated charcoal to reduce absorption In severe cases haemodialysis is considered if required. Treatment includes I.V. infusion of normal saline solution

Home Delivery for Captopril in Your City

Medicine India is just a publishing medium for medicine related information and does not provide services or sales of medicines including captopril.

However, we do publish a comprehensive directory of Pharmacies, Chemists and Druggists in cities all over India. You can use this directory to find the medicine stores in your city (or area) that provide home delivery services for captopril and other medicines and health products. Home delivery services for captopril may be free or they may cost you depending on the pharmacy and the minimum order requirements. It would be best to get this clarified while placing the order.

Please be aware that you should take captopril only if a doctor has recommended or prescribed it. Some or all pharmacies who provide a home delivery service for medicines might insist on a prescription for captopril before they complete the sale. You can get this information while placing the order for captopril with the pharmacy.

Captopril is a generic medicine name and there are several brands available for it. Some of the brands for captopril might be better known than captopril itself. If the pharmacy that's willing to deliver medicines to your home doesn't have captopril in stock, you can ask for one of the branded alternatives for captopril.