Hydrochlorothiazide

Hydrochlorothiazide, abbreviated HCTZ, HCT, or HZT, is a first line diuretic drug of the thiazide class that acts by inhibiting the kidneys' ability to retain water. This reduces the volume of the blood, decreasing blood return to the heart and thus cardiac output and, by other mechanisms, is believed to lower peripheral vascular resistance. Hydrochlorothiazide is sold both as a generic drug and under a large number of brand names, including Apo-Hydro, Aquazide H, Dichlotride, Hydrodiuril, HydroSaluric, Microzide, Esidrex, and Oretic.

Hydrochlorothiazide is also used in combination with many popular drugs used to treat hypertension such as Diovan HCT, Zestoretic, Benicar HCT, Atacand HCT, and Lotensin HCT and others.

Mechanism of action

Hydrochlorothiazide belongs to the thiazide class of diuretics, acting on the kidneys to reduce sodium (Na) reabsorption in the distal convoluted tubule. This increases the osmolarity in the lumen, causing less water to be reabsorbed from the collecting ducts. This leads to increased urinary output.

Indications

HCTZ is often used in the treatment of hypertension, congestive heart failure, symptomatic edema and the prevention of kidney stones. It is effective for nephrogenic diabetes insipidus and is also sometimes used for hypercalciuria, Dent's disease and Meniere's disease.

Hypokalemia, an occasional side effect, can be usually prevented by potassium supplements or by combining hydrochlorothiazide with a potassium-sparing diuretic.

Thiazides are also used in the treatment of osteoporosis. Thiazides decrease mineral bone loss by promoting calcium retention in the kidney, and by directly stimulating osteoblast differentiation and bone mineral formation.^[2]

Side effects

• Hypokalemia
• Hypomagnesemia
• Hyperuricemia and gout
• High blood sugar
• Hyperlipidemia
• Hypercalcemia
• Headache
• Nausea/vomiting
• Photosensitivity
• Weight Gain

See also

• Benicar HCT
• Diovan HCT

External links

• NIH medlineplus druginfo

References

1. ^ Beermann B, Groschinsky-Grind M, Rosén A. (1976). "Absorption, metabolism, and excretion of hydrochlorothiazide". Clin Pharmacol Ther 19 (5 (Pt 1)): 531–7. 
2. ^ Dvorak MM, De Joussineau C, Carter DH, et al. (2007). "Thiazide diuretics directly induce osteoblast differentiation and mineralized nodule formation by interacting with a sodium chloride co-transporter in bone". J. Am. Soc. Nephrol. 18 (9): 2509–16. doi:10.1681/ASN.2007030348. PMID 17656470. http://jasn.asnjournals.org/cgi/pmidlookup?view=long&pmid=17656470.