Brand & Generic Names
Basic Information
- Habit forming? No
- Prescription? Yes
- Available as generic? Yes
- Drug class: Antihypertensive
Uses
- Treatment for high blood pressure.
- May improve congestive heart failure.
- Treatment for Raynaud's 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.
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:
Expands and relaxes blood vessel walls to lower blood pressure.
Time lapse before drug works:
30 minutes.
Don't take with:
Any other medicine without consulting your doctor or pharmacist.
Overdose
SYMPTOMS:
Extreme weakness; loss of consciousness; cold, sweaty skin; weak, rapid pulse; coma.
WHAT TO DO:
- Dial O operator) or 911 (emergency) 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-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:
In case of overdose, see Overdose Section.
Common:
- Rapid heartbeat.
- Vivid dreams,
drowsiness, dizziness.
Infrequent:
- Rash or itchy skin,
blurred vision,
shortness of breath,
difficult breathing,
chest pain.
- Appetite loss,
constipation or
diarrhea, abdominal
pain, nausea, vomiting,
fluid retention, joint or
muscle aches,
weakness and
faintness when arising
from bed or chair.
- Headache, irritability,
depression, dry
mouth, stuffy nose,
increased urination.
Rare:
Decreased sexual
function, numbness or
tingling in hands or feet.
Warnings & Precautions
Don't take if:
- You are allergic to prazosin.
- You are depressed.
- You will have surgery within 2 months, including dental surgery, requiring general or spinal anesthesia.
Before you start, consult your doctor:
- If you experience lightheadedness or fainting with other antihypertensive drugs.
- If you are easily depressed.
- If you have impaired brain circulation or have had a stroke.
- If you have coronary heart disease (with or without angina).
- If you have kidney disease or impaired liver function.
Over age 60:
Begin with no more than 1 mg. per day for first 3 days. Increases should be gradual and supervised by your doctor. Don't stand while taking. Sudden changes in position may cause falls. Sit or lie down promptly if you feel dizzy. If you have impaired brain circulation or coronary heart disease, excessive lowering of blood pressure should be avoided. Report problems to your doctor immediately.
Pregnancy:
Studies inconclusive on harm to unborn child. Consult doctor.
Breast-feeding:
No proven problems. Consult doctor.
Infants & children:
Not recommended.
Prolonged use:
Talk to your doctor about the need for follow-up medical examinations or laboratory studies.
Skin & sunlight:
No problems expected.
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.
Discontinuing:
Don't discontinue without doctor's advice until you complete prescribed dose, even though symptoms diminish or disappear.
Others:
First dose likely to cause fainting. Take it at night and get out of bed slowly next morning.
Possible Interaction with Other Drugs
GENERIC NAME |
COMBINED EFFECT |
| |
------------------------- |
----------------------- |
Amphetamines* |
Decreased doxazosin effect. |
Antihypertensives, |
Increased anti-hypertensive |
other* |
effect. Dosages may require |
|
adjustments. |
Estrogen |
Decreased effect of doxazosin. |
Non-steroidal |
Decreased effect of doxazosin. |
| |
| |
Sympathomimetics* |
Decreased effect of doxazosin. |
Possible Interaction with Other Substances
INTERACTS WITH |
COMBINED EFFECT |
--------------- |
--------------- |
Alcohol: |
Excessive blood pressure drop. |
| |
Beverages: |
None expected. |
| |
Cocaine: |
Increased risk of |
|
heart block and high |
|
blood pressure. |
| |
Foods: |
None expected. |
| |
Marijuana: |
Possible fainting. |
|
Avoid. |
| |
Tobacco: |
Possible spasm of coronary |
|
arteries. Avoid. |
|