Hydrochlorothiazide

Hydrochlorothiazide is a prescription medication used to treat high blood pressure (hypertension), and swelling (edema).  

• Hydrochlorothiazide is available under the following different brand names: Microzide, HydroDiuril, Hydro, Esidrix, HCTZ, Oretic  

Adult and pediatric dosage

Tablet/capsule

• 12.5mg
• 25mg
• 50mg

Hypertension

Adult dosage

• 12.5-50 mg orally once daily

Pediatric dosage

• Children younger than 6 months of age: 1-3 mg/kg/day orally divided every 12 hours; not to exceed 37.5 mg/day
• Children 6 months-2 years: 1-2 mg/kg/day orally in single daily dose or divided twice daily; not to exceed 37.5 mg/day
• Children 2-12 years: 1-3 mg/kg/day; not to exceed 3 mg/kg/day (100 mg/day)

Edema

Adult dosage

• 25-100 mg orally once daily or twice daily; not to exceed 200 mg/day

Pediatric dosage

• Children younger than 6 months of age: 1-3 mg/kg/day orally divided every 12 hours; not to exceed 37.5 mg/day
• Children 6 months-2 years: 1-2 mg/kg/day orally in single daily dose or divided twice daily; not to exceed 37.5 mg/day
• Children 2-12 years: 1-3 mg/kg/day; not to exceed 3 mg/kg/day (100 mg/day)

Dosage Considerations – Should be Given as Follows: 

• See "Dosages."

Common side effects of Hydrochlorothiazide include:

• weakness,  
• nausea, 
• vomiting, 
• fever, 
• chills, 
• tiredness, 
• mouth sores, 
• skin sores, 
• muscle spasm
• diarrhea, and 
• electrolyte imbalance 

Serious side effects of Hydrochlorothiazide include:

• hives, 
• difficulty breathing, 
• swelling in the face, lips, tongue, or throat, 
• fever, 
• sore throat, 
• burning eyes, 
• skin pain, 
• red or purple skin rash with blistering and peeling, 
• lightheadedness, 
• eye pain, 
• vision problems, 
• yellowing of the skin or eyes, 
• pale skin, 
• easy bruising, 
• unusual bleeding (nose, mouth, vagina, or rectum), 
• shortness of breath, 
• wheezing, 
• cough with foamy mucus, 
• chest pain, 
• increased thirst, 
• feeling hot, 
• inability to urinate, 
• heavy sweating, 
• hot and dry skin, 
• increased urination, 
• confusion, 
• vomiting, 
• constipation, 
• muscle pain, 
• leg cramps, 
• bone pain, 
• lack of energy, 
• irregular heartbeats, and
• tingly feeling

Rare side effects of Hydrochlorothiazide include:

• none 

This is not a complete list of side effects and other serious side effects or health problems may occur as a result of the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may report side effects or health problems to FDA at 1-800-FDA-1088.

If your medical doctor is using this medicine to treat your pain, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider or pharmacist first.

• Hydrochlorothiazide has severe interactions with no other drugs.
• Hydrochlorothiazide has serious interactions with at least 12 other drugs.
• Hydrochlorothiazide has moderate interactions with at least 161 other drugs.
• Hydrochlorothiazide has minor interactions with at least 149 other drugs.

This information does not contain all possible interactions or adverse effects. Visit the RxList Drug Interaction Checker for any drug interactions. Therefore, before using this drug, tell your doctor or pharmacist of all the drugs you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist. Check with your physician if you have health questions or concerns.

Contraindications

• Documented hypersensitivity to hydrochlorothiazide or sulfonamides
• Anuria

Effects of drug abuse

• None

Short-Term Effects

• See “What Are Side Effects Associated with Using Hydrochlorothiazide?”

Long-Term Effects

• See “What Are Side Effects Associated with Using Hydrochlorothiazide?”

Cautions

• Use with caution in diabetes mellitus, fluid or electrolyte imbalance, hypercholesterolemia, hyperuricemia or gout, hypercalcemia, hypotension, systemic lupus erythematosus, liver or renal disease, hypokalemia, parathyroid disease
• May aggravate digitalis toxicity
• Sensitivity reactions may occur with or without history of allergy or asthma
• Avoid concurrent use with lithium (reduction of lithium dosage by 50% may be necessary)
• Risk of male sexual dysfunction
• Causes systemic lupus exacerbation or activation
• Azotemia may occur with severe renal disease
• Acute transient myopia and acute angle-closure glaucoma have been reported, particularly with history of sulfonamide or penicillin allergy (hydrochlorothiazide is sulfonamide)
• FDA-approved product labeling for many medications have included a broad contraindication in patients with a prior allergic reaction to sulfonamides; however, recent studies have suggested that cross-reactivity between antibiotic sulfonamides and nonantibiotic sulfonamides is unlikely to occur
• Photosensitization may occur; instruct patients to protect skin from sun and undergo regular skin cancer screening
• Electrolyte disturbances (eg, hypokalemia, hyponatremia, hypochloremic alkalosis) may occur

Pregnancy and Lactation

• Use may be acceptable during the pregnancy. 
• Lactation: Drug excreted in breast milk; use with caution (American Academy of Pediatrics states that it is “compatible with nursing”)