Thiazide diuretics (chlorothiazide)

Thiazide diuretics (chlorothiazide)

1. Pharmacology of thiazide diuretics (chlorothiazide) Presented by Md . Jakir Hossain Dept . of pharmacy Southern university Bangladesh

2. content What is diuretics? What is thiazide diuretics? Chlorothizide- A thiazide diuretics Pharmacology of chorothiazide Mechanism of action Pharmacokinetics Pharmacodynamics Indication Contraindication Side effect Toxicity Dose & dosage form Market preparation Drug interaction Precaution

3. What is diuretics & thiazide diuretics? Diuretics : Something that promotes the formation of urine by the kidney. All diuretics cause a person to 'lose water,' but they do so by diverse means, including inhibiting the kidney's ability to reabsorb sodium, thus enhancing the loss of sodium and consequently water in the urine (loop diuretic); enhancing the excretion of both sodium and chloride in the urine so that water is excreted with them (thiazide diuretic); or blocking the exchange of sodium for potassium, resulting in excretion of sodium and potassium but relatively little loss of potassium (potassium-sparing diuretic) Thiazide diuretics: Thiazide diuretics are a common treatment for high blood pressure. They are also used to clear fluid from the body in conditions where your body accumulates too much fluid, such as heart failure.

4. A thiazide diuretics- Chlorothizide Chlorothiazide is a thiazide diuretic (water pill) that helps prevent your body from absorbing too much salt, which can cause fluid retention. Structure of chorothiazide

5. Mechanism of action As a diuretic, chlorothiazide inhibits active chloride reabsorption at the early distal tubule via the Na-Cl cotransporter, resulting in an increase in the excretion of sodium, chloride, and water. Thiazides like chlorothiazide also inhibit sodium ion transport across the renal tubular epithelium through binding to the thiazide sensitive sodium-chloride transporter. The antihypertensive mechanism of chlorothiazide is less well understood although it may be mediated through its action on carbonic anhydrases in the smooth muscle.

6. Pharmacokinetics Rapidly absorbed following oral administration. Approximately 40% bound to plasma proteins . Chlorothiazide is not metabolized but is eliminated rapidly by the kidney . Chlorothiazide is not metabolized but is eliminated rapidly by the kidney. After oral doses, 10 to 15 percent of the dose is excreted unchanged in the urine. Chlorothiazide crosses the placental but not the blood-brain barrier and is excreted in breast milk . Half life: 45-120 minutes

7. Pharmacodynamics Like other thiazides, chlorothiazide promotes water loss from the body (diuretics). It inhibits Na + /Cl - reabsorption from the distal convoluted tubules in the kidneys. Chlorothiazide affects the distal renal tubular mechanism of electrolyte reabsorption. At maximal therapeutic dosages, all thiazides are approximately equal in their diuretic efficacy. Chlorothiazide increases excretion of sodium and chloride in approximately equivalent amounts. After oral doses, 10-15 percent of the dose is excreted unchanged in the urine. Chlorothiazide crosses the placental but not the blood-brain barrier and is excreted in breast milk.

8. Indication Hypertension Oedema Congestive heart failure Hepatic cirrhosis Diabetes insipidus

9. contraindication Severe renal impairment Severe hepatic impairment Addison disease Hypersensitivity Lactation & pregnancy

10. Side effect Hypotension Photosensitivity, phototoxicity Hyperglycemia Constipation, diarrhoea, nausea, vomiting dizziness., headache, blurred vision, restlessness

11. toxicity Signs of overdose include those caused by electrolyte depletion (hypokalaemia, hypochloraemia, hyponatremia) and dehydration resulting from excessive diuresis . If digitalis has also been administered hypokalaemia may accentuate cardiac arrhythmias.

12. Doses regiment Hypertension: Adult dose: 25mg per day to up to 50mg per day. child:1 to 2 mg per kg per day. Oedema associate with heart failure: Adult dose: 25 to 100mg per day may reduce based of responsive measure.

13. Drug interaction Increased toxicity of lithium. May orthostatic hypotension with barbiturates and narcotic. Increased nephrotoxicity with NSAIDs. Increased hypokalaemia effect with corticosteroids, beta 2 agonists.

14. Market preparation Brand name Pack size & price Company name Acuren 25mg (tab) 100s pack 70 taka Incepta pharmaceuticals Ltd. Acuren 50mg (tab) 100s pack 100 taka Incepta pharmaceuticals Ltd. Hypezide 50mg (tab) 100s pack 100 taka Pacific pharmaceuticals Ltd.

15. Precaution Chlorothiazide should be used with caution in patients with severe renal disease. Thiazides should be used with caution in individuals with impaired hepatic function or progressive liver disease, since minor alterations of fluid and electrolyte balance may precipitate hepatic coma. Sensitivity reactions may be observed in patients with or without a history of allergy or bronchial asthma

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