Terazosin 10mg (ten Mg) Capsules
It is used to treat high blood pressure.It is used to treat the signs of an enlarged prostate.It may be given to you for other reasons. Talk with the doctor.
Drug Class
Antihypertensive, Benign Prostatic Hyperplasia (BPH) agent
Pharmacologic Class
Alpha-1 Adrenergic Blocker
Pregnancy Category
Category C
FDA Approved
Aug 1987
DEA Schedule
Not Controlled
Overview
What is this medicine?
Terazosin is a medication used to treat high blood pressure (hypertension) and symptoms of an enlarged prostate (benign prostatic hyperplasia or BPH) in men. It works by relaxing blood vessels, which lowers blood pressure, and by relaxing muscles in the prostate and bladder, which helps improve urine flow.
How to Use This Medicine
Taking Your Medication
To get the most benefit from this medication, take it exactly as directed by your doctor. Carefully read all the information provided with your prescription, and follow the instructions closely. It's recommended to take this medication at bedtime. Continue taking the medication as prescribed by your doctor or healthcare provider, even if you start feeling well.
Storing and Disposing of Your Medication
To maintain the medication's effectiveness, store it at room temperature, protected from light, and in a dry place. Avoid storing it in a bathroom. Keep all medications in a safe location, out of the reach of children and pets. When disposing of unused or expired medication, do not flush it down the toilet or pour it down the drain unless instructed to do so by your pharmacist. Instead, check with your pharmacist for guidance on the best disposal method, or look into local drug take-back programs.
What to Do If You Miss a Dose
If you miss a dose, take it as soon as you remember. However, if it's close to the time for your next scheduled dose, skip the missed dose and resume your regular dosing schedule. Do not take two doses at the same time or take extra doses. If you miss two or more days of medication, contact your doctor for instructions on how to safely restart your medication regimen.
To get the most benefit from this medication, take it exactly as directed by your doctor. Carefully read all the information provided with your prescription, and follow the instructions closely. It's recommended to take this medication at bedtime. Continue taking the medication as prescribed by your doctor or healthcare provider, even if you start feeling well.
Storing and Disposing of Your Medication
To maintain the medication's effectiveness, store it at room temperature, protected from light, and in a dry place. Avoid storing it in a bathroom. Keep all medications in a safe location, out of the reach of children and pets. When disposing of unused or expired medication, do not flush it down the toilet or pour it down the drain unless instructed to do so by your pharmacist. Instead, check with your pharmacist for guidance on the best disposal method, or look into local drug take-back programs.
What to Do If You Miss a Dose
If you miss a dose, take it as soon as you remember. However, if it's close to the time for your next scheduled dose, skip the missed dose and resume your regular dosing schedule. Do not take two doses at the same time or take extra doses. If you miss two or more days of medication, contact your doctor for instructions on how to safely restart your medication regimen.
Lifestyle & Tips
- Take the first dose at bedtime to minimize the 'first-dose effect' (sudden drop in blood pressure).
- Avoid sudden changes in position (e.g., standing up quickly from sitting or lying down) to prevent dizziness or fainting.
- Avoid or limit alcohol consumption, as it can increase the risk of dizziness and low blood pressure.
- Be cautious when driving or operating machinery, especially when starting treatment or increasing the dose, until you know how the medication affects you.
- Stay hydrated, especially in hot weather or during exercise.
Available Forms & Alternatives
Dosing & Administration
Adult Dosing
Standard Dose:
Initial 1 mg orally once daily at bedtime. Titrate slowly based on patient response and tolerance.
Dose Range:
1 - 20 mg
Condition-Specific Dosing:
Hypertension:
Initial 1 mg at bedtime; may be increased to 2 mg, 5 mg, or 10 mg daily. Usual maintenance dose is 1-5 mg daily, maximum 20 mg daily.
Benign Prostatic Hyperplasia (BPH):
Initial 1 mg at bedtime; may be increased to 2 mg, 5 mg, or 10 mg daily. Usual maintenance dose is 5-10 mg daily, maximum 20 mg daily.
Pediatric Dosing
Neonatal:
Not established
Infant:
Not established
Child:
Not established
Adolescent:
Not established
Dose Adjustments
Renal Impairment:
Mild:
No specific adjustment recommended
Moderate:
No specific adjustment recommended
Severe:
No specific adjustment recommended
Dialysis:
Not significantly removed by dialysis; no specific adjustment recommended, but monitor response.
Hepatic Impairment:
Mild:
Use with caution; monitor for increased hypotensive effects.
Moderate:
Use with caution; monitor for increased hypotensive effects.
Severe:
Use with caution; monitor for increased hypotensive effects. Consider lower starting dose and slower titration.
Pharmacology
Mechanism of Action
Terazosin is a selective competitive antagonist of postsynaptic alpha-1 adrenergic receptors. This blockade leads to vasodilation, reducing peripheral vascular resistance and lowering blood pressure. In BPH, it relaxes the smooth muscle in the prostate and bladder neck, reducing bladder outlet obstruction and improving urine flow.
Pharmacokinetics
Absorption:
Bioavailability:
Approximately 90%
Tmax:
1-2 hours
FoodEffect:
Minimal effect on absorption rate or extent.
Distribution:
Vd:
Approximately 25-30 L
ProteinBinding:
Approximately 90-94%
CnssPenetration:
Limited
Elimination:
HalfLife:
9-12 hours
Clearance:
Not available
ExcretionRoute:
Approximately 60% via feces and 40% via urine.
Unchanged:
Approximately 10% excreted unchanged in urine.
Pharmacodynamics
OnsetOfAction:
Within 15-30 minutes (for blood pressure lowering)
PeakEffect:
1-2 hours
DurationOfAction:
Up to 24 hours
Safety & Warnings
Side Effects
Urgent Side Effects: Seek Medical Help Right Away
While rare, some people may experience severe and potentially life-threatening side effects when taking this medication. If you notice any of the following symptoms, contact your doctor or seek immediate medical attention:
Signs of an allergic reaction, including:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Severe dizziness or fainting
Changes in vision
Abnormal or rapid heartbeat
Swelling in the arms or legs
A painful erection (priapism) or an erection that lasts longer than 4 hours, which can occur even when not engaging in sexual activity. If left untreated, this condition may lead to permanent sexual dysfunction.
Other Possible Side Effects
Like all medications, this drug can cause side effects, although many people may not experience any or may only have mild symptoms. If you encounter any of the following side effects or any other unusual symptoms that bother you or persist, contact your doctor or seek medical attention:
Dizziness, drowsiness, fatigue, or weakness
Nasal congestion
* Headache
This list is not exhaustive, and you may experience other side effects not mentioned here. If you have questions or concerns about side effects, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
While rare, some people may experience severe and potentially life-threatening side effects when taking this medication. If you notice any of the following symptoms, contact your doctor or seek immediate medical attention:
Signs of an allergic reaction, including:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Severe dizziness or fainting
Changes in vision
Abnormal or rapid heartbeat
Swelling in the arms or legs
A painful erection (priapism) or an erection that lasts longer than 4 hours, which can occur even when not engaging in sexual activity. If left untreated, this condition may lead to permanent sexual dysfunction.
Other Possible Side Effects
Like all medications, this drug can cause side effects, although many people may not experience any or may only have mild symptoms. If you encounter any of the following side effects or any other unusual symptoms that bother you or persist, contact your doctor or seek medical attention:
Dizziness, drowsiness, fatigue, or weakness
Nasal congestion
* Headache
This list is not exhaustive, and you may experience other side effects not mentioned here. If you have questions or concerns about side effects, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Seek Immediate Medical Attention If You Experience:
- Severe dizziness or lightheadedness
- Fainting (syncope)
- Palpitations (fast or irregular heartbeat)
- Chest pain
- Swelling in the ankles or feet
- Persistent headache
Before Using This Medicine
Before Taking This Medication: Important Information to Share with Your Doctor
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction you experienced, including any symptoms that occurred.
All medications you are currently taking, including prescription and over-the-counter (OTC) drugs, natural products, and vitamins. This information will help your doctor and pharmacist assess potential interactions between this medication and other substances you are taking.
* Any existing health problems, as this medication may interact with certain conditions or exacerbate underlying health issues.
To ensure your safety, it is crucial to verify that it is safe to take this medication with all your current medications and health conditions. Never start, stop, or change the dose of any medication without first consulting your doctor.
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction you experienced, including any symptoms that occurred.
All medications you are currently taking, including prescription and over-the-counter (OTC) drugs, natural products, and vitamins. This information will help your doctor and pharmacist assess potential interactions between this medication and other substances you are taking.
* Any existing health problems, as this medication may interact with certain conditions or exacerbate underlying health issues.
To ensure your safety, it is crucial to verify that it is safe to take this medication with all your current medications and health conditions. Never start, stop, or change the dose of any medication without first consulting your doctor.
Precautions & Cautions
It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication.
When starting this medication, or after any dose increase, or if you restart it after stopping, do not operate a vehicle or engage in activities that require alertness for 12 hours. Before driving or performing other tasks, ensure you understand how this medication affects you.
To minimize the risk of dizziness or fainting, stand up slowly after sitting or lying down, and exercise caution when navigating stairs.
If you are scheduled to undergo cataract surgery or any other eye procedure, consult with your doctor beforehand.
Monitor your blood pressure as instructed by your healthcare provider.
For individuals taking this medication for an enlarged prostate, follow your doctor's recommendations for regular rectal exams to check the prostate gland and blood tests, including the prostate-specific antigen (PSA) test.
If you have high blood pressure and are taking this medication, discuss the use of over-the-counter (OTC) products with your doctor before taking them, as certain products such as cough or cold medications, diet pills, stimulants, non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen or naproxen, and some natural products or aids can increase blood pressure.
Consult your doctor before consuming alcohol while taking this medication.
As this medication may interfere with certain laboratory tests, inform all your healthcare providers and laboratory personnel that you are taking this medication.
If you are pregnant, plan to become pregnant, or are breastfeeding, discuss the potential benefits and risks of this medication with your doctor to make an informed decision regarding your treatment.
When starting this medication, or after any dose increase, or if you restart it after stopping, do not operate a vehicle or engage in activities that require alertness for 12 hours. Before driving or performing other tasks, ensure you understand how this medication affects you.
To minimize the risk of dizziness or fainting, stand up slowly after sitting or lying down, and exercise caution when navigating stairs.
If you are scheduled to undergo cataract surgery or any other eye procedure, consult with your doctor beforehand.
Monitor your blood pressure as instructed by your healthcare provider.
For individuals taking this medication for an enlarged prostate, follow your doctor's recommendations for regular rectal exams to check the prostate gland and blood tests, including the prostate-specific antigen (PSA) test.
If you have high blood pressure and are taking this medication, discuss the use of over-the-counter (OTC) products with your doctor before taking them, as certain products such as cough or cold medications, diet pills, stimulants, non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen or naproxen, and some natural products or aids can increase blood pressure.
Consult your doctor before consuming alcohol while taking this medication.
As this medication may interfere with certain laboratory tests, inform all your healthcare providers and laboratory personnel that you are taking this medication.
If you are pregnant, plan to become pregnant, or are breastfeeding, discuss the potential benefits and risks of this medication with your doctor to make an informed decision regarding your treatment.
Overdose Information
Overdose Symptoms:
- Profound hypotension (very low blood pressure)
- Dizziness
- Fainting
- Tachycardia (rapid heart rate)
What to Do:
In case of overdose, seek immediate medical attention or call a poison control center (1-800-222-1222). Management typically involves supporting cardiovascular function, elevating the patient's legs, and administering fluids or vasopressors if needed.
Drug Interactions
Major Interactions
- PDE5 inhibitors (e.g., sildenafil, tadalafil, vardenafil): Concomitant use can lead to additive hypotensive effects and symptomatic hypotension. If co-administration is necessary, patients should be stable on alpha-blocker therapy before initiating a PDE5 inhibitor at the lowest dose.
Moderate Interactions
- Other antihypertensive agents (e.g., beta-blockers, calcium channel blockers, diuretics, ACE inhibitors, ARBs): May cause additive hypotensive effects.
- Alcohol: May enhance hypotensive effects.
Minor Interactions
- Not available
Monitoring
Baseline Monitoring
Blood Pressure (BP)
Rationale: To establish baseline and assess the need for treatment.
Timing: Prior to initiation of therapy.
Orthostatic Blood Pressure
Rationale: To assess risk of first-dose syncope and orthostatic hypotension.
Timing: Prior to initiation of therapy (supine and standing).
AUA Symptom Score (for BPH)
Rationale: To quantify baseline BPH symptoms and monitor treatment efficacy.
Timing: Prior to initiation of therapy.
Routine Monitoring
Blood Pressure (BP)
Frequency: Regularly during dose titration and periodically thereafter.
Target: Individualized based on treatment goals (e.g., <130/80 mmHg for hypertension).
Action Threshold: Significant hypotension, especially orthostatic, or inadequate BP control.
Orthostatic Blood Pressure
Frequency: During initial dose titration and if symptoms of orthostasis occur.
Target: No significant drop (e.g., <20 mmHg systolic, <10 mmHg diastolic) upon standing.
Action Threshold: Symptomatic orthostatic hypotension or significant asymptomatic drop.
BPH Symptoms (AUA Symptom Score)
Frequency: Periodically (e.g., every 3-6 months) for BPH patients.
Target: Improvement in score.
Action Threshold: Lack of improvement or worsening of symptoms.
Symptom Monitoring
- Dizziness
- Lightheadedness
- Palpitations
- Syncope (fainting)
- Fatigue
- Nasal congestion
- Headache
- Edema
Special Patient Groups
Pregnancy
Terazosin is classified as Pregnancy Category C. It should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. Animal studies have shown adverse effects at high doses, but there are no adequate and well-controlled studies in pregnant women.
Trimester-Specific Risks:
First Trimester:
Potential for fetal harm, but human data are limited.
Second Trimester:
Potential for fetal harm, but human data are limited.
Third Trimester:
Potential for fetal harm, but human data are limited.
Lactation
Terazosin is excreted in small amounts in human breast milk. The decision to breastfeed while taking terazosin should consider the potential for infant exposure, the benefits of breastfeeding to the infant, and the benefits of treatment to the mother. Monitor the infant for signs of hypotension.
Infant Risk:
Low risk, but monitor for drowsiness, poor feeding, or hypotensive effects.
Pediatric Use
Safety and effectiveness in pediatric patients have not been established. Use is generally not recommended.
Geriatric Use
Geriatric patients may be more sensitive to the hypotensive effects of terazosin, particularly orthostatic hypotension. A lower starting dose (e.g., 0.5 mg if available, or 1 mg with careful monitoring) and slower titration may be appropriate. Monitor blood pressure closely, especially orthostatic readings.
Clinical Information
Clinical Pearls
- The 'first-dose phenomenon' (marked hypotension, dizziness, or syncope) can occur, especially with the initial dose or with rapid dose increases. To mitigate this, the first dose and any subsequent dose increases should be taken at bedtime.
- Patients should be advised to avoid situations where injury could result if syncope occurs (e.g., driving, operating machinery) for 12 hours after the initial dose or dose increase.
- Terazosin is a long-acting alpha-blocker, allowing for once-daily dosing.
- It can be used in patients with both hypertension and BPH, offering a dual benefit.
- If therapy is interrupted for several days, re-initiate with the lowest dose (1 mg) and re-titrate.
Alternative Therapies
- Other Alpha-1 Blockers (for BPH and/or Hypertension): Doxazosin, Prazosin, Tamsulosin, Alfuzosin, Silodosin
- Other Antihypertensives (for Hypertension): ACE inhibitors, Angiotensin Receptor Blockers (ARBs), Calcium Channel Blockers, Thiazide Diuretics, Beta-blockers
- 5-alpha Reductase Inhibitors (for BPH): Finasteride, Dutasteride
- PDE5 Inhibitors (for BPH with ED): Tadalafil
- Anticholinergics (for BPH with overactive bladder symptoms)
- Surgical interventions (for BPH): TURP, laser therapies
Cost & Coverage
Average Cost:
Varies widely, typically $10-$50 per 30 tablets
Generic Available:
Yes
Insurance Coverage:
Tier 1 or 2 (Generic)
General Drug Facts
If your symptoms or health issues persist or worsen, it's essential to contact your doctor for further guidance. To ensure your safety, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so be sure to check with your pharmacist for more information. If you have any questions or concerns about your medication, don't hesitate to reach out to your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek medical attention. When seeking help, be prepared to provide details about the medication taken, the amount, and the time it happened.