Chlorthalidone Pharmacology


About Chlorthalidone
Monosulfamyl diuretic, long acting phthalimidine derivative, thiazides like diuretic, Antihypertensive/diuretic
Mechanism of Action of Chlorthalidone
It is long acting phthalimidine derivative exerts thiazides like diuretic action by acting at site-3(central dilating segment of early distal tubule). It binds to Na+-Cl- symporter and inhibits Na+-Cl- symport at the luminal membrane. It has additional carbonic anhydrase inhibitory actions in proximal tubules. It increases natriuresis, kaliuresis and diuresis. It decreases Ca2+ excretion and increases Mg2+ and hence used to correct hypocalcaemia associated with hypoparathyroidism. The antihypertensive actions of the drug may be attributable to depletion of sodium and subsequent reduction in plasma volume and a decrease in peripheral resistance. Decrease in peripheral resistance is due to either the loss of sodium from the arteriolar wall or a direct action on the vascular bed. It is an effective drug in edema associated with congestive heart failure.
Pharmacokinets of Chlorthalidone
Absorption: Slowly absorbed after oral administration. Distribution: It preferentially bound to renal tissues for prolonged periods. Metabolism: It is not significantly metabolized in the body. Excretion: Excreted mainly through urine and a small portion is excreted through bile.
Onset of Action for Chlorthalidone
1 to 3 hours
Duration of Action for Chlorthalidone
48 to 72 hours
Half Life of Chlorthalidone
40 to 50 hours
Side Effects of Chlorthalidone
5.Dry mouth
10.Elevated levels of glucose, calcium, and lipids
11.Altered liver function tests
12.Altered kidney function tests
13.Gastro intestinal disturbances
15.Visual impairment
16.Electrolyte imbalance
Contra-indications of Chlorthalidone
1.Hypersensitivity to the drug
4.Renal impairment
5.Hepatic impairment
9.Addison`s disease
10.Chronic obstructive pulmonary diseases
Special Precautions while taking Chlorthalidone
2.Hepatic diseases
3.Renal impairment
4.Fluid and electrolyte imbalance
6.Severe heart failure
8.Diabetes mellitus
9.Ventricular extra systoles
Pregnancy Related Information
Old Age Related Information
Use with caution
Breast Feeding Related Information
Children Related Information
Use with caution
Indications for Chlorthalidone
2.Oedema associated with heart failure
3.Oedema due to renal and hepatic diseases
4.Ascites due to cirrhosis.
Interactions for Chlorthalidone
Cholestyramine & Colestipol : decrease absorption of chlorthalidone.
Diazoxide : Additive action may cause hyperglycemia, hyperuricaemia and hypotension.
Digitalis : Diuretic induced hypokalaemia may precipitate digitalis toxicity.
Lithium : Chlorthalidone potentiates therapeutic and toxic effects by decreasing its renal excretion.
Frusemide :Synergy leading to profound diuresis and greater than predicted electrolyte loss.
Non-depolarizing muscle relaxants : Diuretic induced hypokalaemia enhances efficacy.
Sulfonylureas : Efficacy decreased due to chlorthalidone induced glucose intolerance.
Chlorpropamide : Hypokalemia.
Propantheline : Bioavailability of chlorthalidone increased.
Metoclopramide : Bioavailability of chlorthalidone decreased.
NSAID?s : Natriuretic effect of chlorthalidone decreased.
Typical Dosage for Chlorthalidone
Hypertension: 25mg daily. Increased to 50mg if required; depending up on the patient`s response.
Oedema: Starts with 50mg. Increased to 100 to 200mg on alternate days; if required.
Maintenance dosage: 25 to 50mg daily or on alternate days.
Children: Hypertension:2mg/kg/day; thrice a week.
Schedule of Chlorthalidone
Storage Requirements for Chlorthalidone
Store at a cool dry place; and at a temperature below 30 degree C. in a well closed container.
Effects of Missed Dosage of Chlorthalidone
Effects of Overdose of Chlorthalidone
Treatment is supportive and symptomatic. Remove drug from the body by induced emesis and gastric lavage. Monitor and support fluid and electrolyte balance.

Home Delivery for Chlorthalidone in Your City

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

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 chlorthalidone and other medicines and health products. Home delivery services for chlorthalidone 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 chlorthalidone 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 chlorthalidone before they complete the sale. You can get this information while placing the order for chlorthalidone with the pharmacy.

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