Hydrochlorothiazide
Brand name HydroSaluric
Used in the following combined preparations Acezide, Capozide, Co-Betaloc, Dyazide, Moducren, Moduretic, and others
GENERAL INFORMATION
Hydrochlorothiazide belongs to the thiazide group of diuretic drugs, which remove excess water from the body and reduce oedema (fluid retention) in people with congestive heart failure, kidney disorders, cirrhosis of the liver, and premenstrual syndrome. This drug is used to treat high blood pressure (see Antihypertensive drugs).
Hydrochlorothiazide increases the loss of potassium in the urine, which can cause a variety of symptoms, and increases the likelihood of irregular heart rhythms, particularly in patients who are taking drugs such as digoxin. For this reason, potassium supplements are often given with hydrochlorothiazide.
INFORMATION FOR USERS
Your drug prescription is tailored for you. Do not alter dosage without checking with your doctor.
How taken
Tablets.
Frequency and timing of doses
Once daily, or every 2 days, early in the day.
Adult dosage range
25-200mg daily.
Onset of effect
Within 2 hours.
Duration of action
6-12 hours.
Diet advice
Use of this drug may reduce potassium in the body. Eat plenty of fresh fruit and vegetables. Discuss with your doctor the advisability of reducing your salt intake.
Storage
Keep in a closed container in a cool, dry place out of the reach of children. Protect from light.
Missed dose
No cause for concern, but take as soon as you remember. However, if it is late in the day do not take the missed dose, or you may have to get up during the night to pass urine. Take the next scheduled dose as usual.
Stopping the drug
Do not stop the drug without consulting your doctor; symptoms may recur.
Exceeding the dose
An occasional unintentional extra dose is unlikely to be a cause for concern. But if you notice any unusual symptoms, or if a large overdose has been taken, notify your doctor.
POSSIBLE ADVERSE EFFECTS
Most effects are caused by excessive loss of potassium. This can usually be put right by taking a potassium supplement. In rare cases, gout may occur in susceptible people, and certain forms of diabetes may become more difficult to control.
INTERACTIONS
Non-steroidal anti-inflammatory drugs (NSAIDs)
Some NSAIDs may reduce the diuretic effect of hydrochlorothiazide, whose dosage may need to be adjusted.
Digoxin
Adverse effects may be increased if excessive potassium is lost.
Corticosteroids
These drugs further increase loss of potassium from the body when taken with hydrochlorothiazide.
Lithium
Hydrochlorothiazide may increase lithium levels in the blood, leading to a risk of serious adverse effects.
QUICK REFERENCE
Drug group Thiazide diuretic
Overdose danger rating Low
Dependence rating Low
Prescription needed Yes
Available as generic No
SPECIAL PRECAUTIONS
Be sure to tell your doctor if:
You have long-term liver or kidney problems.
You have had gout.
You have diabetes.
You are taking other medications.
Pregnancy
Not usually prescribed. May cause jaundice in the newborn baby. Discuss with your doctor.
Breast-feeding
The drug passes into the breast milk, but at normal doses adverse effects on the baby are unlikely. Discuss with your doctor.
Infants and children
Not usually prescribed. Reduced dose necessary.
Over 60
Increased likelihood of adverse effects.
Driving and hazardous work
No special problems.
Alcohol
Keep consumption low. Hydrochlorothiazide increases the likelihood of dehydration and hangovers after consumption of alcohol.
PROLONGED USE
Excessive loss of potassium and imbalances of other salts may result.
Monitoring
Blood tests may be performed periodically to check kidney function and levels of potassium and other salts.
