Hydrochlorothiazide

Drug #363

Hydrochlorothiazide is a prototype drug of thiazide diuretics. Hydrochlorothiazide is antihypertensive agent. It increases the urination and reduces the amount of water and sodium retained by the body. The drugs in this class are formally called benzothiadiazide, usually shortened to thiazides. The nature of the hetrocyclic rings and the substitution on these ring may vary among the congeners but all of them retain a unsubstituted sulfonamide group. Development of thiazides and other modern diuretics began when a perceptive physician noticed that patients receiving sulfanilamide, an early antimicrobial agent, developed metabolic acidosis and a very alkaline urine. Careful study revealed that the drug was causing sodium bicarbonate diuresis. The realization that it could be useful diuretic led first to the development of acetazolamide and then to the thiazides.

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Primary Characteristics

It is of Synthetic origin and belongs to Thiazide.

It belongs to NaCl cotransport inhibitor pharmacological group on the basis of mechanism of action and also classified in Antihypertensive Agent, Combination pharmacological group.

Molecular Weight: 297.7 · pK_a: 7.9, 9.2 · Solubility in Water: Insoluble · Solubility in Alcohol: soluble · Non-proprietary name: Hydrochlorothiazide.

Molecular structure of Hydrochlorothiazide

Pharmacokinetics

Distribution: Hydrochlorothiazide has a volume of distribution is 3.6-7.8 l/kg. plasma protein binding is 68%.

Elimination: it is metabolised via Not metabolized, plasma half-life is 5.6-14.8hrs, renal excretion is major,Urine(as unchanged drug).

Indications

Hydrochlorothiazide is primarily indicated in conditions like Diabetes insipidus, Edema, Hypercalciuria, Hypertension, Nephrolithiasis, Nephrotic syndrome, Oedema, Proximal renal tubular acidosis.

Hydrochlorothiazide is also indicated for secondary conditions like Exercise induced hyperkalemia, Osteoporosis, Renal hypophosphatemic rickets.

Contraindications

Hydrochlorothiazide is contraindicated in conditions like Diabetes mellitus, Gout, Renal diseases, Anuria, Hyperlipidemia, Liver diseases, Ecg abnormalities.

Dosage

Hydrochlorothiazide's dosage details are as follows:

Dose	Single Dose	Frequency	Route	Instructions
Adult Dosage
31.25 mg/day	31.25 mg/day	Every 24h	PO	Hypertension (upto 100mg/day)
62.5 mg	62.5 mg	Every 24h	PO	As Required For oedema (upto 200mg/day)
Paediatric Dosage (20kg)
2.5 mg/kg	2.5 mg/kg	Every 12h	Oral
Neonatal Dosage (3kg)
1 mg/kg	1 mg/kg	Every 12h	Oral

Drug Interactions

Unknown17 interactions

21 interactions

Always consult your physician for the change of dose regimen or an alternative drug of choice that may strictly be required.

Side Effects

Hydrochlorothiazide in overdosage may give rise to further complications which include Pancreatitis , Stevens johnson syndrome , Stevens johnson syndrome , Systemic lupus erythematosus , Pneumonitis , Idiosyncratic hypersensitiviy reactions .

Hydrochlorothiazide produces potentially life-threatening effects which include Hyponatremia, Metabolic disturbances, Idiosyncratic hypersensitivity reactions, Hyponatremia. Careful monitoring is needed with proper medical management.

The signs and symptoms that are produced after acute overdosage of Hydrochlorothiazide are Coma, Volume depletion, Hypokalemia , Hypochloremic alkalosis, Hypersensitivity reactions, Electrolyte disturbances, Lethargy, Hemolytic anemia, Hyponatremia.

Hydrochlorothiazide is known to cause more or less tolerable side effects which are usually transient. These include Allergic reactions, Cardiac arrhythmias , Dry mouth, Ectopic beats, Fatigue, Hyperglycemia, Hyperlipidemia, Hyperuricemia , Hypokalemia , Hypomagnesemia, Lethargy, Paralysis , parasthesia, Restlessness, Thirst, UTI , Weakness.

Warnings / Precautions

Hydrochlorothiazide should be used with caution in patients with diabetes, kidney or liver disease or any drug allergy. Caution must be observed when eating large amounts of food high in potassium such as bananas, baked potatoes, raisins, cooked spinach and other foods. Alcoholic beverages may increase the effects of this drug, causing dizziness or lightheadedness, so limit alcohol intake. It should be used with caution while engaging in activities requiring alertness. This drug changes fluid balance, cause dizziness, if change from a lying to a standing position too rapidly, avoid this by sitting up a few minutes before rising. It should be used with caution during pregnancy or lactation. Use with caution in certain pateints with 4% gout. Photosensensiation can occur exacerbation or actiration. Use with caution with moderate or high cholestraheacone.

Interference in Pathology

Hydrochlorothiazide may interfere in the diagnosis of Periodic determination of serum electrolytes.

Available Brands

Click on a strength to view available brands.

Single Ingredient

Inj

100 mg

Tabs

25 mg 50 mg

Multi-Ingredient Combinations

Tabs

12.5 mg 15 mg 2.5 mg 25 mg 5 mg 50 mg 6.25 mg

Storage Conditions

Hydrochlorothiazide should be stored . Tab.

Drug Classification

1.12.4 — Drugs used in heart failure
2.16.1 — Thiazide and related diuretics

Manufacturers

Manufacturers of Hydrochlorothiazide in Pakistan: