hydrochlorothiazide

Drug Name

Generic Name : hydrochlorothiazide

Brand Name: Apo-Hydro (CAN), Ezide, HydroDIURIL, Hydro-Par, Microzide Capsules

Classification: Thiazide diuretic

Pregnancy Category B

Dosage & Route

Available forms: Tablets—25, 50, 100 mg; solution—50 mg/5 mL; capsules—12.5 mg

ADULTS
  • Edema: 25–200 mg daily PO until dry weight is attained. Then, 25–100 mg daily PO or intermittently, up to 200 mg/day.
  • Hypertension: 12.5–50 mg PO.
  • Calcium nephrolithiasis: 50 mg daily or bid PO.
PEDIATRIC PATIENTS

General guidelines: 2.2 mg/kg/day PO in 2 doses.

  • 2–12 yr: 37.5–100.0 mg/day in 2 doses.
  • 6 mo–2 yr: 12.5–37.5 mg/day in 2 doses.
  • < 6 mo: Up to 3.3 mg/kg/day in 2 doses.
Therapeutic actions
  • Hydrochlorothiazide inhibits the reabsorption of Na and chloride at the beginning of the distal convoluted tubule. It causes natriuretic effect mainly by decreasing Na and chloride reabsorption in the cortical segment of the ascending limb of the loop of Henle by inhibition of a specific Na+Cl- co-transporter.
Indications
  • Adjunctive therapy in edema associated with CHF, cirrhosis, corticosteroid, and estrogen therapy; renal impairment
  • Hypertension as sole therapy or in combination with other antihypertensives
  • Unlabeled uses: Calcium nephrolithiasis alone or with amiloride or allopurinol to prevent recurrences in hypercalciuric or normal calciuric patients; diabetes insipidus, especially nephrogenic diabetes insipidus; osteoporosis
Adverse effects
  • Volume depletion and electrolyte imbalance, dry mouth, thirst, lethargy, drowsiness, muscle pain and cramps, hypotension, hypersensitivity reactions e.g. rashes, photosensitivity, thrombocytopenia, jaundice, pancreatitis; fatigue, weakness; may precipitate an attack of gout; impotence, hyperglycaemia; anorexia, gastric irritation, nausea, vomiting, constipation, diarrhoea, sialadenitis, dizziness, raised Ca concentration.
  • Potentially Fatal: Hypersensitivity reactions.
Contraindications
  • Severe hepatic and renal impairment, Addison’s disease, preexisting hypercalcaemia, anuria, sulphonamide allergy. Pregnancy, lactation.
Nursing considerations
Assessment
  • History: Allergy to thiazides, sulfonamides; fluid or electrolyte imbalance; renal or liver disease; gout; SLE; glucose tolerance abnormalities, diabetes mellitus; hyperparathyroidism; manic-depressive disorders; lactation, pregnancy
  • Physical: Skin color, lesions, edema; orientation, reflexes, muscle strength; pulses, baseline ECG, BP, orthostatic BP, perfusion; R, pattern, adventitious sounds; liver evaluation, bowel sounds, urinary output patterns; CBC, serum electrolytes, blood glucose, LFTs, renal function tests, serum uric acid, urinalysis
Interventions
  • Give with food or milk if GI upset occurs.
  • Mark calendars or provide other reminders of drug for alternate day or 3–5 days/wk therapy.
  • Reduce dosage of other antihypertensives by at least 50% if given with thiazides; readjust dosages gradually as BP responds.
  • Administer early in the day so increased urination will not disturb sleep.
  • Measure and record weights to monitor fluid changes.
Teaching points
  • Record intermittent therapy on a calendar, or use prepared, dated envelopes. Take drug early so increased urination will not disturb sleep. Drug may be taken with food or meals if GI upset occurs.
  • Weigh yourself on a regular basis, at the same time and in the same clothing; record weight on your calendar.
  • You may experience these side effects: Increased volume and frequency of urination; dizziness, feeling faint on arising, drowsiness (avoid rapid position changes; hazardous activities, like driving; and alcohol); sensitivity to sunlight (use sunglasses, wear protective clothing, or use a sunscreen); decrease in sexual function; increased thirst (sucking on sugarless lozenges and frequent mouth care may help); gout attack (report any sudden joint pain).
  • Report weight change of more than 3 pounds in 1 day, swelling in your ankles or fingers, unusual bleeding or bruising, dizziness, trembling, numbness, fatigue, muscle weakness or cramps.