Hydrochlorothiazide

ATC code

C03AA03

Therapeutic class

Thiazide diuretic · Low-ceiling diuretic, thiazide

Forms

oral tablet

Brand names

Hidroclorotiazida Normon (ES) · Microzide (US) · Oretic (US) · Esidrex (FR)

Overall confidence

medium

Regulatory sources consulted

AEMPS CIMA FT_90833 (https://cima.aemps.es/cima/dochtml/ft/90833/FT_90833.html)
CredibleMeds.org
AEMPS CIMA · nº registro 90833 ↗

Approved indications

Treatment of edema of cardiac, hepatic, or renal origin.
Treatment of arterial hypertension, as monotherapy or in combination with other antihypertensives.
Treatment of nephrogenic diabetes insipidus.
Prevention of calcium oxalate stone formation in patients with idiopathic hypercalciuria.

Contraindications

Absolute

Hypersensitivity to hydrochlorothiazide or other sulfonamide-derived drugs.
Anuria.
Severe renal impairment (creatinine clearance < 30 ml/min).
Severe hepatic impairment.
Refractory hypokalemia, hyponatremia, hypercalcemia.

Clinical warnings

Major warning · Risk of fluid and electrolyte imbalance (hypokalemia, hyponatremia, hypomagnesemia, hypercalcemia). Monitor electrolytes periodically. — AEMPS
Major warning · Increased risk of non-melanoma skin cancer with cumulative and prolonged use. Advise sun protection. — AEMPS
May precipitate gout attacks in susceptible patients due to hyperuricemia. — AEMPS
May impair glucose tolerance and require dose adjustment of antidiabetic drugs. — AEMPS

Drug interactions

HighLithiumN05AN01
Mechanism: Thiazide diuretics reduce the renal clearance of lithium, increasing the risk of toxicity.
Recommendation: Concomitant use is generally contraindicated. If necessary, monitor lithium levels closely.
AEMPS CIMA
ModerateNSAIDs (Nonsteroidal Anti-Inflammatory Drugs)M01A
Mechanism: NSAIDs can attenuate the diuretic, natriuretic, and antihypertensive effect of hydrochlorothiazide.
Recommendation: Monitor blood pressure and renal function, especially when initiating or changing the dose.
AEMPS CIMA
HighQT-prolonging drugs
Mechanism: Hydrochlorothiazide-induced hypokalemia increases the risk of ventricular arrhythmias (Torsades de Pointes) when combined with QT-prolonging drugs.
Recommendation: Correct hypokalemia before initiating treatment. Monitor electrolytes and ECG periodically.
CredibleMeds.org

Adverse events

Common (≥1%)

hypokalemia · hyperuricemia · hyperglycemia · hyperlipidemia · orthostatic hypotension · dizziness · hyponatremia

Rare but serious

pancreatitis · acute interstitial nephritis · non-melanoma skin cancer · acute angle-closure glaucoma · non-cardiogenic pulmonary edema · necrotizing vasculitis

Pregnancy and lactation

FDA category: B

Contraindicated during the second and third trimesters of pregnancy. It is excreted in breast milk, so a decision should be made whether to discontinue nursing or the drug.