hydrochlorothiazide (redirected from Hzt)

hydrochlorothiazide /hy·dro·chlo·ro·thi·a·zide/ (-klor″o-thi´ah-zīd) a thiazide diuretic, used for treatment of hypertension and edema.

---

hy·dro·chlo·ro·thi·a·zide (hdr-klôr-th-zd, -zd)

n. Abbr. HCTZ

A diuretic used alone or in combination with other drugs primarily to treat hypertension.

---

hydrochlorothiazide

[-klôr′ōthī′əzīd]

a thiazide diuretic.

indications It is prescribed in the treatment of mild to moderate hypertension and edema caused by congestive heart failure or protein loss by the kidney (nephritic syndrome).

contraindications Anuria or known hypersensitivity to this drug, to other thiazide medication, or to sulfonamide derivatives prohibits its use.

adverse effects Among the more serious adverse effects are hypoglycemia, hyperglycemia, hyperuricemia, and hypersensitivity reactions.

---

hydrochlorothiazide,

n brand names: Esidrix, HydroDIURIL;
drug class: thiazide diuretic;
action: acts on distal tubule by increasing excretion of water, sodium, chloride, potassium;
uses: edema, hypertension, diuresis, congestive heart failure.

---

hydrochlorothiazide

a thiazide diuretic; sometimes used for an antidiuretic effect in the treatment of diabetes insipidus in dogs.

---

hydrochlorothiazide

Apo-Hydro (CA), Diuchlor H (CA), Hydro-Par, Microzide, Neo-Codema (CA), Novo-Hydrazide (CA), Oretic, Urozide (CA)

Pharmacologic class: Thiazide diuretic

Therapeutic class: Diuretic, antihypertensive

Pregnancy risk category B

Action

Increases sodium and water excretion by inhibiting sodium reabsorption in distal tubules; promotes excretion of chloride, potassium, magnesium, and bicarbonate. Also may produce arteriolar dilation, reducing blood pressure.

Availability

Capsules: 12.5 mg

Oral solution: 10 mg/ml, 100 mg/ml

Tablets: 25 mg, 50 mg, 100 mg

⊘Indications and dosages

➣ Edema caused by heart failure, renal dysfunction, cirrhosis, corticosteroid therapy, or estrogen therapy

Adults: 25 to 100 mg P.O. daily as a single dose or in divided doses. Maximum dosage is 200 mg/day.

➣ Mild to moderate hypertension

Adults: Initially, 12.5 mg daily P.O.; then, based on blood pressure response, may give 12.5 to 50 mg/day P.O. Higher dosages may be given in refractory cases.

Children ages 6 months to 12 years: 2.2 mg/kg P.O. daily in two divided doses

Children younger than 6 months: Up to 3.3 mg/kg P.O. daily in two divided doses

Off-label uses

• Hypercalcemia
• Ménière's disease

Contraindications

• Hypersensitivity to drug, other thiazides, sulfonamides, or tartrazine
• Renal decompensation or anuria

Precautions

Use cautiously in:
• renal or severe hepatic impairment, fluid or electrolyte imbalances, gout, systemic lupus erythematosus, hyperparathyroidism, glucose tolerance abnormalities, bipolar disorder
• pregnant or breastfeeding patients.

Administration

• Give with food or milk if GI upset occurs.
• Administer early in day so diuretic effect doesn't disturb sleep.

Route	Onset	Peak	Duration
P.O.	2 hr	3-6 hr	6-12 hr

Adverse reactions

CNS: dizziness, drowsiness, lethargy, headache, insomnia, nervousness, vertigo, asthenia, asterixis, paresthesias, confusion, fatigue, encephalopathy

CV: chest pain, orthostatic hypotension, ECG changes, thrombophlebitis, arrhythmias

EENT: nystagmus

GI: nausea, vomiting, epigastric distress, anorexia, pancreatitis

GU: polyuria, nocturia, erectile dysfunction, loss of libido, renal failure

Hematologic: anemia, hemolytic anemia, agranulocytosis, leukopenia, thrombocytopenia

Hepatic: jaundice, hepatitis

Metabolic: dehydration, gout, hyperglycemia, hypokalemia, hypocalcemia, hypovolemia, hypomagnesemia, hyponatremia, hypophosphatemia, hyperuricemia, hypochloremic alkalosis

Musculoskeletal: muscle cramps

Skin: photosensitivity, urticaria, rash, dermatitis, purpura, alopecia, flushing

Other: fever, weight loss, anaphylaxis

Interactions

Drug-drug. Allopurinol: increased risk of hypersensitivity reaction

Amphotericin B, corticosteroids, digoxin, mezlocillin, piperacillin, ticarcillin: increased risk of hypokalemia

Antihypertensives, barbiturates, nitrates, opioids: increased hypotension

Cholestyramine, colestipol: decreased hydrochlorothiazide absorption

Digoxin: increased risk of hypokalemia

Lithium: decreased excretion and increased blood level of lithium

Nonsteroidal anti-inflammatory drugs: decreased hydrochlorothiazide efficacy

Drug-diagnostic tests. Bilirubin, blood and urine glucose (in diabetic patients), calcium, creatinine, uric acid: increased levels

Cholesterol, low-density lipoproteins, magnesium, potassium, protein-bound iodine, sodium, triglycerides, urinary calcium: decreased levels

Drug-herbs. Dandelion: interference with diuretic activity

Ginkgo: decreased antihypertensive effect

Licorice, stimulant laxative herbs (aloe, cascara sagrada, senna): increased risk of hypokalemia

Drug-behaviors. Alcohol use: increased hypotension

Sun exposure: increased risk of photosensitivity

Patient monitoring

• Monitor blood pressure, fluid intake and output, and daily weight.
• Assess electrolyte levels, especially potassium. Monitor for signs and symptoms of hypokalemia.
• Monitor blood urea nitrogen and creatinine levels.
• Check blood glucose level in diabetic patients.
• Assess for signs and symptoms of gout attacks in patients with gouty arthritis.

Patient teaching

• Advise patient to take with food or milk if GI upset occurs.
• Tell patient to take early in day to avoid nighttime urination.
• Instruct patient to track intermittent doses on calendar.
• Tell patient to weigh himself daily, at same time on same scale and wearing same clothes.
☞ Instruct patient to report decreased urination, swelling, unusual bleeding or bruising, dizziness, fatigue, numbness, and muscle weakness or cramping.
• Instruct patient to move slowly when sitting up or standing, to avoid dizziness from sudden blood pressure decrease.
• Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration and alertness.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, herbs, and behaviors mentioned above.