Brand & Generic Names
Basic Information
- Habit forming? No
- Prescription needed? Yes
- Available as generic? No
- Drug class: Antihypertensive
Uses
- Treatment of high blood pressure.
- Reduces fluid retention (edema) caused by conditions such as
heart disorders and liver disease.
Dosage & Usage Information
How to take:
Tablet--Swallow with liquid. If you can't swallow whole, crumble
tablet and take with liquid or food. Don't exceed dose.
When to take:
At the same time each day.
If you forget a dose:
Take as soon as you remember up to 2 hours
late. If more than 2 hours, wait for next scheduled dose (don't
double this dose).
What drug does:
Relaxes and allows expansion of blood vessel walls.
Forces sodium and water excretion, reducing body fluid.
Reduced body fluid and relaxed arteries lower blood pressure.
Time lapse before drug works:
4 to 6 hours. May require several
weeks to lower blood pressure.
Don't take with:
Any medicine that will decrease mental alertness such as
alcohol, antihistamines, cold/cough medicines, sedatives,
tranquilizers, narcotics, prescription pain medicine,
barbiturates, seizure medicine, anesthetics.
Overdose
SYMPTOMS:
Vomiting; fainting; rapid, irregular, slow heartbeat;
diminished reflexes; cramps; shortness of breath; weakness;
drowsiness; weak pulse; coma.
WHAT TO DO:
- Dial 911 (emergency) or O (operator) for an ambulance or
medical help. Then give first aid immediately.
- If patient is unconscious and not breathing, give mouth-to-
mouth breathing. If there is no heartbeat, use cardiac massage
and mouth-to-mouth breathing (CPR). Don't try to make patient
vomit. If you can't get help quickly, take patient to nearest
emergency facility.
- See EMERGENCY Information.
Possible Adverse Reactions or Side Effects
Life-threatening:
Irregular heartbeat, Discontinue. Seek
weak pulse. emergency treatment.
Common:
Dry mouth, increased
thirst, muscle cramps,
nausea or vomiting,
mood changes,
drowsiness.
Infrequent:
Vomiting, diminished
sex desire and
performance, insomnia,
dizziness, diarrhea,
constipation, appetite
loss.
Rare:
- Jaundice; easy
bruising or bleeding;
sore throat, fever,
mouth ulcers; rash or
hives; joint pain;
flank pain; abdominal
pain.
- Cold fingers and toes,
nightmares.
Warnings & Precautions
Don't take if:
- You are allergic to any thiazide diuretic drug or alpha-
adrenergic blocker.
- You are under age 12.
Before you start, consult your doctor:
- If you are allergic to any sulfa drug.
- If you have gout, liver, pancreas or kidney disorder, a
peripheral circulation disorder (intermittent claudication,
Buerger's disease), history of depression, heart disease.
- If you will have surgery within 2 months, including dental
surgery, requiring general or spinal anesthesia.
Over age 60:
Adverse reactions and side effects may be more frequent and
severe than in younger persons, especially dizziness and
excessive potassium loss.
Pregnancy:
Risk to unborn child outweighs drug benefits. Don't use.
Breast-feeding:
Drug passes into milk. Avoid drug or discontinue nursing until
you finish medicine. Consult doctor for advice on maintaining
milk supply.
Infants & children:
Use only after careful medical supervision after age 12. Avoid
before age 12.
Prolonged use:
- Don't discontinue without consulting doctor. Dose may require
gradual reduction if you have taken drug for a long time. Doses
of other drugs may also require adjustment.
- Continued use may cause fluid retention, requiring addition of
diuretic to treatment program.
- Request yearly eye examinations.
- Talk to your doctor about the need for follow-up medical
examinations or laboratory studies.
Skin & sunlight:
May cause rash or intensify sunburn in areas exposed to sun or
sunlamp.
Driving, piloting or hazardous work:
Don't drive or pilot aircraft until you learn how medicine
affects you. Don't work around dangerous machinery. Don't climb
ladders or work in high places. Danger increases if you drink
alcohol or take medicine affecting alertness and reflexes, such
as antihistamines, tranquilizers, sedatives, pain medicine,
narcotics and mind-altering drugs.
Discontinuing:
Don't discontinue abruptly. May cause rebound high blood
pressure, anxiety, chest pain, insomnia, headache, nausea,
irregular heartbeat, flushed face, sweating.
Others:
- Hot weather and fever may cause dehydration and drop in blood
pressure. Dose may require temporary adjustment. Weigh daily and
report any unexpected weight decreases to your doctor.
- May cause rise in uric acid, leading to gout.
- May cause blood-sugar rise in diabetics.
Possible Interaction with Other Drugs
GENERIC NAME |
COMBINED EFFECT |
| |
------------------------ |
----------------------- |
ACE inhibitors*: |
Possible excessive |
captopril, enalapril, |
potassium in blood. |
| |
Allopurinol |
Decreased allopurinol effect. |
Antidepressants, |
Dangerous drop in |
tricyclic (TCA)* |
blood pressure. Avoid combination |
|
unless under medical supervision. |
Antihypertensives, |
Excessive blood |
other* |
pressure drop. |
Appetite |
Decreased clonidine |
suppressants* |
effect. |
Barbiturates* |
Increased chlorthalidone effect. |
Beta-adrenergic |
Possible precipitous |
blockers* |
change in blood pressure. |
Carteolol |
Increased antihypertensive effect. |
Cholestyramine |
Decreased chlorthalidone effect. |
Cortisone drugs* |
Excessive potassium loss that |
|
causes dangerous heart rhythms. |
Digitalis |
Excessive potassium |
preparations* |
loss that causes dangerous heart |
|
rhythms. |
Diuretics* |
Excessive blood pressure drop. |
Fenfluramine |
Possible increased clonidine |
|
effect. |
Guanfacine |
Blood pressure control impaired. |
Indapamide |
Increased diuretic effect. |
Lithium |
Increased effect of lithium. |
MAO inhibitors* |
Increased chlorthalidone effect. |
Nabilone |
Greater depression of central |
|
nervous system. |
Nicardipine |
Blood pressure drop. Dosages may |
|
require adjustment. |
Nitrates* |
Possible excessive blood pressure |
|
drop. |
Potassium |
Decreased potassium |
supplements* |
effect. |
Probenecid |
Decreased probenecid effect. |
Sedatives* or central |
Increased sedative effect of |
nervous system (CNS) |
both drugs. |
| |
Sotalol |
Decreased antihypertensive effect. |
Terazosin |
Decreases effectiveness of |
|
terazosin. |
Possible Interaction with Other Substances
INTERACTS WITH |
COMBINED EFFECT |
--------------- |
--------------- |
Alcohol: |
Increased sensitivity to sedative |
|
effect of alcohol and very low |
|
blood pressure. Avoid. |
| |
| |
Caffeine-containing |
Decreased clonidine |
drinks. |
effect. |
| |
Cocaine |
Increased risk of heart block and |
|
high blood pressure. |
| |
| |
Licorice. |
Excessive potassium loss that |
|
causes dangerous heart rhythm. |
| |
Marijuana: |
Weakness on standing. May increase |
|
blood pressure. |
| |
Tobacco: |
None expected. |
|