Brand & Generic Names
- Habit forming? No
- Prescription needed? Yes
- Available as generic? No
- Drug class: Antihypertensive
Controls, but doesn't cure, high blood pressure.
Dosage & Usage Information
How to take:
Tablet--Swallow with liquid or food to lessen stomach
irritation. If you can't swallow whole, crumble tablet and take
with liquid or food.
When to take:
At the same times 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 muscle cells of small arteries.
Time lapse before drug works:
Don't take with:
Any other medicine without consulting your doctor or pharmacist.
Severe dizziness, slow heartbeat, unusual tiredness or
weakness, pinpoint pupils, fainting, 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
- See EMERGENCY Information.
Possible Adverse Reactions or Side Effects
In case of overdose, see Overdose section.
- Dry mouth, drowsiness.
- Insomnia, weakness.
- Irregular heartbeat,
shakiness in hands.
- Dizziness, appetite
vomiting, painful or
Warnings & Precautions
Don't take if:
You are allergic to any sympathomimetic drug.
Before you start, consult your doctor:
- If you have blood disease.
- If you have heart disease.
- If you have liver disease.
- If you have diabetes or overactive thyroid.
- 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. Hot weather may cause need to
Risk to unborn child outweighs drug benefits. Don't use.
Unknown effect. Consult doctor.
Infants & children:
Side effects tend to diminish. Request uric-acid and kidney-
function studies periodically.
Skin & sunlight:
No problems expected.
Driving, piloting or hazardous work:
Avoid if you feel dizzy; otherwise, no problems expected.
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. Abruptly discontinuing
may cause anxiety, chest pain, salivation, headache, abdominal
cramps, fast heartbeat, increased sweating, tremors, insomnia.
- Stay away from high-sodium foods. Lose weight if you are
- May interfere with the accuracy of some medical tests.
Possible Interaction with Other Drugs
||potassium in blood.
||pressure more than either alone.
||May be beneficial, but requires
||Blood pressure control more
|Central nervous system
||Increased brain depression. Avoid.
||Toxic effect on the central nervous
||Decreases blood pressure more than
||either alone. May be beneficial,
||but requires dosage adjustment.
||Dangerous increased effects of
||ethinamate. Avoid combining.
||Increased depressant effects of
||May increase depressant effects of
||High alcohol content of leucovorin
||may cause adverse effects.
||Increased sedative effect, perhaps
||to dangerous level. Avoid.
||Greater depression of central
||Blood pressure drop. Dosages may
||Dangerous blood pressure drop.
||Increased depressive effects of
Possible Interaction with Other Substances
||Decrease salt intake to increase
||beneficial effects of guanabenz.
||Decreased guanabenz effect.