Terazosin (capsules)
Generic name: terazosin hydrochloride · Brand names: Hytrin, Tezruly (oral solution, ANI Pharmaceuticals)
Quick facts
Drug class
Value
alpha-1-selective adrenoceptor blocking agent (alpha-blocker)
Source text (exact source wording)
Terazosin hydrochloride, an alpha-1-selective adrenoceptor blocking agent, is a quinazoline derivative
Rx or otc
Value
Rx only
Source
Amici Pharma terazosin capsules label (DailyMed set ID 4007dbd3-e850-43e7-8a56-8735e31063cd), How Supplied 'Rx only'
Forms and strengths
- Capsules: 1 mg, 2 mg, 5 mg, 10 mg (terazosin, as the hydrochloride; Amici label How Supplied and Description)
Generic available
Value
yes
Source
Amici label marketing category ANDA (ANDA074823); DailyMed list shows many ANDA capsule labelers
Common use one line
Treats symptomatic benign prostatic hyperplasia (BPH) and high blood pressure (hypertension).
What it is used for
Terazosin treats the symptoms of benign prostatic hyperplasia (BPH) and also treats high blood pressure. Approximately 70% of patients had more urine flow and better BPH symptoms. It can be used alone or with other blood pressure medicines such as diuretics or beta-blockers. The long-term effects on surgery or other BPH complications are not yet known.
Source
Amici Pharma terazosin capsules label (DailyMed set ID 4007dbd3-e850-43e7-8a56-8735e31063cd)
Section
INDICATIONS AND USAGE
Confidence
high
Medlineplus source
https://medlineplus.gov/druginfo/meds/a693046.html
Source text (exact source wording)
Terazosin capsules, USP are indicated for the treatment of symptomatic benign prostatic hyperplasia (BPH). There is a rapid response, with approximately 70% of patients experiencing an increase in urinary flow and improvement in symptoms of BPH when treated with terazosin capsules, USP. The long-term effects of terazosin capsules, USP on the incidence of surgery, acute urinary obstruction or other complications of BPH are yet to be determined. Terazosin capsules, USP are also indicated for the treatment of hypertension. Terazosin capsules, USP can be used alone or in combination with other antihypertensive agents such as diuretics or beta-adrenergic blocking agents.
Medlineplus source text (exact source wording)
Terazosin is used to: treat benign prostatic hyperplasia (BPH; enlarged prostate that can cause difficulty urinating, painful urination or increased urinary frequency or urgency). treat high blood pressure. Terazosin is in a class of medications called alpha-blockers.
How it works
Terazosin blocks alpha-1 receptors, which relaxes smooth muscle in the bladder neck and prostate so urine flows more easily. It also relaxes blood vessels, which lowers blood pressure.
Source
Amici Pharma terazosin capsules label (DailyMed set ID 4007dbd3-e850-43e7-8a56-8735e31063cd)
Section
CLINICAL PHARMACOLOGY, Pharmacodynamics A and B
Confidence
high
Source text (exact source wording)
The reduction in symptoms and improvement in urine flow rates following administration of terazosin is related to relaxation of smooth muscle produced by blockade of alpha-1 adrenoceptors in the bladder neck and prostate. Because there are relatively few alpha-1 adrenoceptors in the bladder body, terazosin is able to reduce the bladder outlet obstruction without affecting bladder contractility. In animals, terazosin causes a decrease in blood pressure by decreasing total peripheral vascular resistance. The vasodilatory hypotensive action of terazosin appears to be produced mainly by blockade of alpha-1 adrenoceptors.
Dosage: adults
For both BPH and high blood pressure, start with 1 mg at bedtime and do not start higher. For BPH, the dose is raised step by step to 2 mg, 5 mg, or 10 mg once daily, and 10 mg for a minimum of 4 to 6 weeks may be needed to judge the response. For high blood pressure, the usual range is 1 mg to 5 mg once a day, and some patients may benefit from up to 20 mg per day. If treatment stops for several days or longer, restart with the initial dosing regimen.
Source
Amici Pharma terazosin capsules label (DailyMed set ID 4007dbd3-e850-43e7-8a56-8735e31063cd)
Section
DOSAGE AND ADMINISTRATION (BPH and Hypertension)
Confidence
high
Source text (exact source wording)
Benign Prostatic Hyperplasia - Initial Dose: 1 mg at bedtime is the starting dose for all patients, and this dose should not be exceeded as an initial dose. Subsequent Doses: The dose should be increased in a stepwise fashion to 2 mg, 5 mg, or 10 mg once daily to achieve the desired improvement of symptoms and/or flow rates. Doses of 10 mg once daily are generally required for the clinical response. Therefore, treatment with 10 mg for a minimum of 4 to 6 weeks may be required to assess whether a beneficial response has been achieved. Hypertension - Initial Dose: 1 mg at bedtime is the starting dose for all patients, and this dose should not be exceeded. Subsequent Doses: The dose may be slowly increased to achieve the desired blood pressure response. The usual recommended dose range is 1 mg to 5 mg administered once a day; however, some patients may benefit from doses as high as 20 mg per day. Doses over 20 mg do not appear to provide further blood pressure effect and doses over 40 mg have not been studied. If terazosin administration is discontinued for several days or longer, therapy should be reinstituted using the initial dosing regimen.
Dosage: children
Safety and effectiveness in children have not been determined.
Source
Amici Pharma terazosin capsules label (DailyMed set ID 4007dbd3-e850-43e7-8a56-8735e31063cd)
Section
PRECAUTIONS, Pediatric Use
Confidence
high
Source text (exact source wording)
Safety and effectiveness in pediatric patients have not been determined.
Dosage adjustments
Drug interaction caps
Use caution with other blood pressure medicines, especially verapamil, to avoid significant low blood pressure. A lower dose and re-titration of either medicine may be needed. Low blood pressure has been reported with PDE-5 inhibitors.
Source
Amici Pharma terazosin capsules label (DailyMed set ID 4007dbd3-e850-43e7-8a56-8735e31063cd)
Section
DOSAGE AND ADMINISTRATION, Use With Other Drugs
Confidence
high
Source text (exact source wording)
Caution should be observed when terazosin capsules are administered concomitantly with other antihypertensive agents, especially the calcium channel blocker verapamil, to avoid the possibility of developing significant hypotension. When using terazosin capsules and other antihypertensive agents concomitantly, dosage reduction and retitration of either agent may be necessary (see PRECAUTIONS). Hypotension has been reported when terazosin capsules have been used with phosphodiesterase-5 (PDE-5) inhibitors.
Kidney
Kidney impairment had no significant effect on how terazosin is eliminated, and no dose change for hemodialysis appears to be necessary.
Source
Amici Pharma terazosin capsules label (DailyMed set ID 4007dbd3-e850-43e7-8a56-8735e31063cd)
Section
CLINICAL PHARMACOLOGY, Pharmacokinetics
Confidence
high
Source text (exact source wording)
Impaired renal function had no significant effect on the elimination of terazosin, and dosage adjustment of terazosin to compensate for the drug removal during hemodialysis (approximately 10%) does not appear to be necessary.
Liver
The label text read has no liver dosing statement.
Source
Amici Pharma terazosin capsules label (DailyMed set ID 4007dbd3-e850-43e7-8a56-8735e31063cd)
Confidence
low
Elderly
In people 70 and older the average half-life was 14.0 hours, versus 11.4 hours in ages 20 to 39, and clearance was 31.7% lower. The label gives no separate elderly dose.
Source
Amici Pharma terazosin capsules label (DailyMed set ID 4007dbd3-e850-43e7-8a56-8735e31063cd)
Section
CLINICAL PHARMACOLOGY, Pharmacokinetics
Confidence
high
Medlineplus source
https://medlineplus.gov/druginfo/meds/a693046.html
Source text (exact source wording)
In a study that evaluated the effect of age on terazosin pharmacokinetics, the mean plasma half-lives were 14.0 and 11.4 hours for the age group ≥ 70 years and the age group of 20 to 39 years, respectively. After oral administration the plasma clearance was decreased by 31.7% in patients 70 years of age or older compared to that in patients 20 to 39 years of age.
Medlineplus source text (exact source wording)
talk to your doctor about the risks and benefits of taking terazosin if you are 65 years of age or older. Older adults should not usually take terazosin to treat high blood pressure, because it is not as safe or effective as other medications that can be used to treat the same condition.
Missed dose
Label
The label has no standard missed-dose rule. If you miss several days, talk to your doctor, because you may have to restart at 1 mg.
Source
Amici Pharma terazosin capsules label (DailyMed set ID 4007dbd3-e850-43e7-8a56-8735e31063cd)
Section
DOSAGE AND ADMINISTRATION; PATIENT INFORMATION
Source text (exact source wording)
If terazosin administration is discontinued for several days or longer, therapy should be reinstituted using the initial dosing regimen. Talk with your doctor if you don’t take it for a few days, you may have to restart it at a 1 mg dose and be cautious about possible dizziness.
Medlineplus source
https://medlineplus.gov/druginfo/meds/a693046.html
Confidence
high
Medlineplus source text (exact source wording)
Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one. Check with your doctor if you have missed two or more doses.
Overdose
If an overdose causes low blood pressure, supporting the heart and circulation comes first, for example by lying flat, then fluids, and vasopressors if needed. Dialysis may not help because terazosin is 90-94% protein bound. In case of overdose call poison control at 1-800-222-1222.
Source
Amici Pharma terazosin capsules label (DailyMed set ID 4007dbd3-e850-43e7-8a56-8735e31063cd)
Section
OVERDOSAGE
Confidence
high
Medlineplus source
https://medlineplus.gov/druginfo/meds/a693046.html
Source text (exact source wording)
Should overdosage of terazosin capsules lead to hypotension, support of the cardiovascular system is of first importance. Restoration of blood pressure and normalization of heart rate may be accomplished by keeping the patient in the supine position. If this measure is inadequate, shock should first be treated with volume expanders. If necessary, vasopressors should then be used and renal function should be monitored and supported as needed. Laboratory data indicate that terazosin capsules are 90-94% protein bound; therefore, dialysis may not be of benefit.
Medlineplus source text (exact source wording)
In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at https://www.poisonhelp.org/help. If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911. Symptoms of overdose may include the following: dizziness; lightheadedness; fainting; blurred vision
Storage
Store at 20° to 25°C (68° to 77°F) and protect from light and moisture. Details are from the Amici label and may differ for other makers.
Source
Amici Pharma terazosin capsules label (DailyMed set ID 4007dbd3-e850-43e7-8a56-8735e31063cd)
Section
HOW SUPPLIED (Amici labeler-specific)
Confidence
high
Source text (exact source wording)
Store at 20° to 25°C (68° to 77°F) [see USP Controlled Room Temperature]. Protect from light and moisture. Dispense in a tight, light-resistant container.
Medlineplus source text (exact source wording)
Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from light and excess heat and moisture (not in the bathroom).
Boxed warning
NONEContraindications
Do not use if you are known to be allergic to terazosin hydrochloride.
Source
Amici Pharma terazosin capsules label (DailyMed set ID 4007dbd3-e850-43e7-8a56-8735e31063cd)
Section
CONTRAINDICATIONS
Confidence
high
Source text (exact source wording)
Terazosin capsules are contraindicated in patients known to be hypersensitive to terazosin hydrochloride.
Warnings and precautions
The first dose or first few days can cause a marked drop in blood pressure and fainting, and a similar effect can happen if therapy is stopped for several days and restarted. Treatment should always start with 1 mg at bedtime. Avoid driving or hazardous tasks when starting. In trials of nearly 2000 hypertensive patients, fainting was reported in about 1%. The risk is greatest in the first seven days.
Heading
WARNINGS: Syncope and “First-dose” Effect
Source
Amici Pharma terazosin capsules label (DailyMed set ID 4007dbd3-e850-43e7-8a56-8735e31063cd)
Section
WARNINGS: Syncope and “First-dose” Effect
Confidence
high
Source text (exact source wording)
Terazosin capsules, like other alpha-adrenergic blocking agents, can cause marked lowering of blood pressure, especially postural hypotension, and syncope in association with the first dose or first few days of therapy. A similar effect can be anticipated if therapy is interrupted for several days and then restarted. To decrease the likelihood of syncope or excessive hypotension, treatment should always be initiated with a 1 mg dose of terazosin capsules, given at bedtime. The 2 mg, 5 mg and 10 mg capsules are not indicated as initial therapy. The patient should be cautioned to avoid situations, such as driving or hazardous tasks, where injury could result should syncope occur during initiation of therapy. In multiple dose clinical trials involving nearly 2000 hypertensive patients treated with terazosin capsules, syncope was reported in about 1% of patients. The risk of the events is greatest during the initial seven days of treatment, but continues at all time intervals.
Rarely, a painful erection lasting for hours (priapism) has happened with terazosin and similar drugs. It can lead to permanent impotence if not treated promptly.
Heading
WARNINGS: Priapism
Source
Amici Pharma terazosin capsules label (DailyMed set ID 4007dbd3-e850-43e7-8a56-8735e31063cd)
Section
WARNINGS: Priapism
Confidence
high
Source text (exact source wording)
Rarely, (probably less than once in every several thousand patients), terazosin and other α 1-antagonists have been associated with priapism (painful penile erection, sustained for hours and unrelieved by sexual intercourse or masturbation). Two or three dozen cases have been reported. Because this condition can lead to permanent impotence if not promptly treated, patients must be advised about the seriousness of the condition (see PRECAUTIONS: Information for Patients).
Prostate cancer and BPH cause similar symptoms and can exist together, so patients thought to have BPH should be examined for prostate cancer before starting.
Heading
PRECAUTIONS: Prostatic Cancer
Source
Amici Pharma terazosin capsules label (DailyMed set ID 4007dbd3-e850-43e7-8a56-8735e31063cd)
Section
PRECAUTIONS: Prostatic Cancer
Confidence
high
Source text (exact source wording)
Carcinoma of the prostate and BPH cause many of the same symptoms. These two diseases frequently co-exist. Therefore, patients thought to have BPH should be examined prior to starting terazosin capsule therapy to rule out the presence of carcinoma of the prostate.
A pupil problem called IFIS has happened during cataract surgery in patients on or previously on alpha-1 blockers. The eye surgeon should be prepared, and stopping the drug before surgery does not appear to help.
Heading
PRECAUTIONS: Intraoperative Floppy Iris Syndrome (IFIS)
Source
Amici Pharma terazosin capsules label (DailyMed set ID 4007dbd3-e850-43e7-8a56-8735e31063cd)
Section
PRECAUTIONS: Intraoperative Floppy Iris Syndrome (IFIS)
Confidence
high
Source text (exact source wording)
Intraoperative Floppy Iris Syndrome (IFIS) has been observed during cataract surgery in some patients on/or previously treated with alpha-1 blockers. The patient’s ophthalmologist should be prepared for possible modifications to their surgical technique, such as the utilization of iris hooks, iris dilator rings, or viscoelastic substances. There does not appear to be a benefit of stopping alpha-1 blocker therapy prior to cataract surgery.
Dizziness, lightheadedness, and palpitations from low blood pressure occurred in some 28% of patients in hypertension trials. In BPH trials, 21% had one or more of dizziness, hypotension, postural hypotension, syncope, or vertigo.
Heading
PRECAUTIONS: Orthostatic Hypotension
Source
Amici Pharma terazosin capsules label (DailyMed set ID 4007dbd3-e850-43e7-8a56-8735e31063cd)
Section
PRECAUTIONS: Orthostatic Hypotension
Confidence
high
Source text (exact source wording)
While syncope is the most severe orthostatic effect of terazosin capsules (see WARNINGS), other symptoms of lowered blood pressure, such as dizziness, lightheadedness and palpitations, were more common and occurred in some 28% of patients in clinical trials of hypertension. In BPH clinical trials, 21% of the patients experienced one or more of the following: dizziness, hypotension, postural hypotension, syncope, and vertigo. Patients with occupations in which such events represent potential problems should be treated with particular caution.
Avoid driving or hazardous tasks for 12 hours after the first dose, after a dose increase, and after restarting following a break. Drowsiness can occur.
Heading
PRECAUTIONS: Information for Patients
Source
Amici Pharma terazosin capsules label (DailyMed set ID 4007dbd3-e850-43e7-8a56-8735e31063cd)
Section
PRECAUTIONS: Information for Patients
Confidence
high
Source text (exact source wording)
Patients should be made aware of the possibility of syncopal and orthostatic symptoms, especially at the initiation of therapy, and to avoid driving or hazardous tasks for 12 hours after the first dose, after a dosage increase, and after interruption of therapy when treatment is resumed. Patients should also be told that drowsiness or somnolence can occur with terazosin capsules, requiring caution in people who must drive or operate heavy machinery.
Pregnancy and breastfeeding
Safety in pregnancy has not been established, and terazosin is not recommended during pregnancy unless the benefit justifies the risk. It is not known whether it passes into breast milk, so caution is advised when nursing.
Source
Amici Pharma terazosin capsules label (DailyMed set ID 4007dbd3-e850-43e7-8a56-8735e31063cd)
Section
PRECAUTIONS: Pregnancy (Category C) and Nursing Mothers
Confidence
high
Medlineplus source
https://medlineplus.gov/druginfo/meds/a693046.html
Source text (exact source wording)
There are no adequate and well-controlled studies in pregnant women and the safety of terazosin in pregnancy has not been established. Terazosin capsules are not recommended during pregnancy unless the potential benefit justifies the potential risk to the mother and fetus. Nursing Mothers: It is not known whether terazosin is excreted in breast milk. Because many drugs are excreted in breast milk, caution should be exercised when terazosin capsules are administered to a nursing woman.
Medlineplus source text (exact source wording)
tell your doctor if you are pregnant, plan to become pregnant, or are breastfeeding. If you become pregnant while taking terazosin, call your doctor.
Side effects
Common
In BPH trials, the only events significantly more common with terazosin than placebo were asthenia (weakness or tiredness), postural hypotension, dizziness, somnolence, nasal congestion or rhinitis, and impotence. In high blood pressure trials they were asthenia, blurred vision, dizziness, nasal congestion, nausea, peripheral edema, palpitations, and somnolence.
Source
Amici Pharma terazosin capsules label (DailyMed set ID 4007dbd3-e850-43e7-8a56-8735e31063cd)
Section
ADVERSE REACTIONS (BPH and Hypertension)
Confidence
medium
Note
No label-stated 'most common' list exists; the 'significantly more common than placebo' lists are the closest label statement.
Source text (exact source wording)
Benign Prostatic Hyperplasia: Asthenia, postural hypotension, dizziness, somnolence, nasal congestion/rhinitis, and impotence were the only events that were significantly (p ≤ 0.05) more common in patients receiving terazosin capsules than in patients receiving placebo. Table 1 summarizes those adverse events reported for patients in these trials when the incidence rate in the terazosin group was at least 1%, and was greater than that for the placebo group, or where the reaction is of clinical interest. Hypertension: Asthenia, blurred vision, dizziness, nasal congestion, nausea, peripheral edema, palpitations and somnolence were the only symptoms that were significantly (p < 0.05) more common in patients receiving terazosin capsules than in patients receiving placebo. Table 3 summarizes those adverse experiences reported for patients in these trials where the prevalence rate in the terazosin group was at least 5%, where the prevalence rate for the terazosin group was at least 2% and was greater than the prevalence rate for the placebo group, or where the reaction is of particular interest.
Less common
In the BPH trials, dizziness was reported by 9.1% of terazosin patients versus 4.2% on placebo, asthenia by 7.4% versus 3.3%, and postural hypotension by 3.9% versus 0.8%. In the high blood pressure trials, dizziness was 19.3% versus 7.5%, asthenia 11.3% versus 4.3%, and headache 16.2% versus 15.8%. The label also lists many other reactions seen in at least 1% of 1987 patients.
Source
Amici Pharma terazosin capsules label (DailyMed set ID 4007dbd3-e850-43e7-8a56-8735e31063cd)
Section
ADVERSE REACTIONS, Table 1 (BPH, terazosin N = 636 vs placebo N = 360) and Table 3 (Hypertension, terazosin N = 859 vs placebo N = 506)
Confidence
high
Note
Table values transcribed from the printed tables; column order was reconstructed from the label's row sequence.
Source text (exact source wording)
TABLE 1 (BPH), terazosin vs placebo: Asthenia 7.4% * vs 3.3%; Flu Syndrome 2.4% vs 1.7%; Headache 4.9% vs 5.8%; Hypotension 0.6% vs 0.6%; Palpitations 0.9% vs 1.1%; Postural Hypotension 3.9% * vs 0.8%; Syncope 0.6% vs 0.0%; Nausea 1.7% vs 1.1%; Peripheral Edema 0.9% vs 0.3%; Weight Gain 0.5% vs 0.0%; Dizziness 9.1% * vs 4.2%; Somnolence 3.6% * vs 1.9%; Vertigo 1.4% vs 0.3%; Dyspnea 1.7% vs 0.8%; Nasal Congestion/Rhinitis 1.9% * vs 0.0%; Blurred Vision/Amblyopia 1.3% vs 0.6%; Impotence 1.6% * vs 0.6%; Urinary Tract Infection 1.3% vs 3.9% *. (*p ≤ 0.05 comparison between groups.) TABLE 3 (Hypertension), terazosin vs placebo: Asthenia 11.3% * vs 4.3%; Back Pain 2.4% vs 1.2%; Headache 16.2% vs 15.8%; Palpitations 4.3% * vs 1.2%; Postural Hypotension 1.3% vs 0.4%; Tachycardia 1.9% vs 1.2%; Nausea 4.4% * vs 1.4%; Edema 0.9% vs 0.6%; Peripheral Edema 5.5% * vs 2.4%; Weight Gain 0.5% vs 0.2%; Pain – Extremities 3.5% vs 3.0%; Depression 0.3% vs 0.2%; Dizziness 19.3% * vs 7.5%; Libido Decreased 0.6% vs 0.2%; Nervousness 2.3% vs 1.8%; Paresthesia 2.9% vs 1.4%; Somnolence 5.4% * vs 2.6%; Dyspnea 3.1% vs 2.4%; Nasal Congestion 5.9% * vs 3.4%; Sinusitis 2.6% vs 1.4%; Blurred Vision 1.6% * vs 0.0%; Impotence 1.2% vs 1.4%. (*Statistically significant at p=0.05 level.) The following additional adverse reactions were reported by at least 1% of 1987 patients who received terazosin in controlled or open, short- or long-term clinical trials studies or have been reported during marketing experience: Body as a Whole: Chest pain, facial edema, fever, abdominal pain, neck pain, shoulder pain. Cardiovascular System: Arrhythmia, vasodilation. Digestive System: Constipation, diarrhea, dry mouth, dyspepsia, flatulence, vomiting. Metabolic/Nutritional Disorders: Gout. Musculoskeletal System: Arthralgia, arthritis, joint disorder, myalgia. Nervous System: Anxiety, insomnia. Respiratory System: Bronchitis, cold symptoms, epistaxis, flu symptoms, increased cough, pharyngitis, rhinitis. Skin and Appendages: Pruritus, rash, sweating. Special Senses: Abnormal vision, conjunctivitis, tinnitus. Urogenital System: Urinary frequency, urinary incontinence primarily reported in postmenopausal women, urinary tract infection.
Serious
After approval, rare allergic reactions including anaphylaxis, priapism, low platelets (thrombocytopenia), atrial fibrillation, and IFIS during cataract surgery were reported. The label also warns of fainting after the first dose.
MedlinePlus says to call your doctor right away or get emergency help for hives, rash, itching, trouble breathing, a rapid, pounding, or irregular heartbeat, or a painful erection lasting for hours. Report side effects to FDA MedWatch at 1-800-FDA-1088.
Label source
Amici Pharma terazosin capsules label (DailyMed set ID 4007dbd3-e850-43e7-8a56-8735e31063cd)
Label section
WARNINGS; ADVERSE REACTIONS, Post-marketing Experience
Medlineplus source
https://medlineplus.gov/druginfo/meds/a693046.html
Medlineplus section
What side effects can this medication cause?
Confidence
high
Label source text (exact source wording)
Post-marketing experience indicates that in rare instances patients may develop allergic reactions, including anaphylaxis, following administration of terazosin hydrochloride. There have been reports of priapism and thrombocytopenia during post-marketing surveillance. Atrial fibrillation has been reported. During cataract surgery, a variant of small pupil syndrome known as Intraoperative Floppy Iris Syndrome (IFIS) has been reported in association with alpha-1 blocker therapy (see PRECAUTIONS).
Medlineplus source text (exact source wording)
Some side effects can be serious. If you experience any of these symptoms, call your doctor immediately or seek emergency medical treatment: hives, rash, itching, shortness of breath or difficulty breathing; rapid, pounding, or irregular heartbeat; painful erection of the penis that lasts for hours
Led to discontinuation
In the placebo-controlled trials, stopping early because of side effects was not statistically different between terazosin and placebo. Dizziness was the most frequent reason in both trials (2.0% versus 1.1% in BPH and 3.1% versus 0.4% in high blood pressure).
Source
Amici Pharma terazosin capsules label (DailyMed set ID 4007dbd3-e850-43e7-8a56-8735e31063cd)
Section
ADVERSE REACTIONS, Tables 2 and 4
Confidence
medium
Note
Table 2 and Table 4 pairings reconstructed from the label's row order. Pairings follow the label's terazosin-column-then-placebo-column row order.
Source text (exact source wording)
In the placebo-controlled clinical trials, the rates of premature termination due to adverse events were not statistically different between the placebo and terazosin groups. TABLE 2 (BPH) discontinuation, terazosin vs placebo: Fever 0.5% vs 0.0%; Headache 1.1% vs 0.8%; Postural Hypotension 0.5% vs 0.0%; Syncope 0.5% vs 0.0%; Nausea 0.5% vs 0.3%; Dizziness 2.0% vs 1.1%; Vertigo 0.5% vs 0.0%; Dyspnea 0.5% vs 0.3%; Blurred Vision/Amblyopia 0.6% vs 0.0%; Urinary Tract Infection 0.5% vs 0.3%. TABLE 4 (Hypertension) discontinuation, terazosin vs placebo: Asthenia 1.6% vs 0.0%; Headache 1.3% vs 1.0%; Palpitations 1.4% vs 0.2%; Postural Hypotension 0.5% vs 0.0%; Syncope 0.5% vs 0.2%; Tachycardia 0.6% vs 0.0%; Nausea 0.8% vs 0.0%; Peripheral Edema 0.6% vs 0.0%; Dizziness 3.1% vs 0.4%; Paresthesia 0.8% vs 0.2%; Somnolence 0.6% vs 0.2%; Dyspnea 0.9% vs 0.6%; Nasal Congestion 0.6% vs 0.0%; Blurred Vision 0.6% vs 0.0%.
Interactions
Drugs
Verapamil raised terazosin levels (AUC up 24% after 3 weeks) in a study of 24 people. Caution is advised to avoid significant low blood pressure.
Name
Verapamil
Source
Amici Pharma terazosin capsules label (DailyMed set ID 4007dbd3-e850-43e7-8a56-8735e31063cd)
Section
PRECAUTIONS, Use With Other Drugs
Source text (exact source wording)
In a study (n=24) where terazosin and verapamil were administered concomitantly, terazosin’s mean AUC 0-24 increased 11% after the first verapamil dose and after 3 weeks of verapamil treatment it increased by 24% with associated increases in C max (25%) and C min (32%) means.
Using other blood pressure medicines can cause significant low blood pressure, so a lower dose and re-titration may be needed.
Name
Other antihypertensive agents
Source
Amici Pharma terazosin capsules label (DailyMed set ID 4007dbd3-e850-43e7-8a56-8735e31063cd)
Section
DOSAGE AND ADMINISTRATION, Use With Other Drugs
Source text (exact source wording)
Caution should be observed when terazosin capsules are administered concomitantly with other antihypertensive agents, especially the calcium channel blocker verapamil, to avoid the possibility of developing significant hypotension. When using terazosin capsules and other antihypertensive agents concomitantly, dosage reduction and retitration of either agent may be necessary (see PRECAUTIONS).
Low blood pressure has been reported when terazosin is used with PDE-5 inhibitors.
Name
Phosphodiesterase-5 (PDE-5) inhibitors
Source
Amici Pharma terazosin capsules label (DailyMed set ID 4007dbd3-e850-43e7-8a56-8735e31063cd)
Section
DOSAGE AND ADMINISTRATION
Source text (exact source wording)
Hypotension has been reported when terazosin capsules have been used with phosphodiesterase-5 (PDE-5) inhibitors.
In a study of 6 people, terazosin did not change how captopril was handled by the body.
Name
Captopril
Source
Amici Pharma terazosin capsules label (DailyMed set ID 4007dbd3-e850-43e7-8a56-8735e31063cd)
Section
PRECAUTIONS, Use With Other Drugs
Source text (exact source wording)
In a study (n=6) where terazosin and captopril were administered concomitantly, plasma disposition of captopril was not influenced by concomitant administration of terazosin and terazosin maximum plasma concentrations increased linearly with dose at steady-state after administration of terazosin plus captopril (see DOSAGE AND ADMINISTRATION).
Adding terazosin to diuretics and several beta-blockers produced no unexpected interactions in controlled trials.
Name
Diuretics and beta-blockers
Source
Amici Pharma terazosin capsules label (DailyMed set ID 4007dbd3-e850-43e7-8a56-8735e31063cd)
Section
PRECAUTIONS, Drug Interactions
Source text (exact source wording)
In controlled trials, terazosin capsules have been added to diuretics, and several beta-adrenergic blockers; no unexpected interactions were observed.
Food and alcohol
Taking it right after a meal has a minimal effect on how much is absorbed, but peak levels are delayed by about 40 minutes. MedlinePlus says to take it with or without food.
Name
Food
Source
Amici Pharma terazosin capsules label (DailyMed set ID 4007dbd3-e850-43e7-8a56-8735e31063cd)
Section
CLINICAL PHARMACOLOGY, Pharmacokinetics
Source text (exact source wording)
Administration of capsules immediately after meals had a minimal effect on the extent of absorption. The time to reach peak plasma concentration however, was delayed by about 40 minutes.
No alcohol statement was found in the label text read. The patient leaflet in the label lists reducing alcohol as a lifestyle change for high blood pressure.
Name
Alcohol
No grapefruit statement was found in the sources read.
Name
Grapefruit
Other
The label says no interactions were observed in a variety of other treatments, though these were not formal interaction studies.
Name
Alpha-blocker interactions studied without findings
Source
Amici Pharma terazosin capsules label (DailyMed set ID 4007dbd3-e850-43e7-8a56-8735e31063cd)
Section
PRECAUTIONS, Drug Interactions
Source text (exact source wording)
Terazosin capsules have also been used in patients on a variety of concomitant therapies; while these were not formal interaction studies, no interactions were observed.
Patient tips
Label
The first dose can cause a sudden drop in blood pressure, so get up slowly, avoid driving or hazardous tasks until you know how it affects you, and sit or lie down if dizzy. Call your doctor or go to an emergency room for an erection that lasts too long. Take it every day at the prescribed dose and do not share it.
Source
Amici Pharma terazosin capsules label (DailyMed set ID 4007dbd3-e850-43e7-8a56-8735e31063cd)
Section
PATIENT INFORMATION
Source text (exact source wording)
Terazosin Capsules, USP Can Cause a Sudden Drop in Blood Pressure After the VERY FIRST DOSE. You may feel dizzy, faint, or “light-headed” particularly after you get up from bed or from a chair. If you take terazosin capsules at bedtime but need to get up from bed to go to the bathroom, get up slowly and cautiously until you are sure how the medicine affects you. You should not drive or do any hazardous tasks until you are used to the effects of the medication. If you begin to feel dizzy, sit or lie down until you feel better. If you have a prolonged abnormal erection, call your doctor or go to an emergency room as soon as possible. Follow your doctor’s instructions about how to take terazosin capsules. You must take it every day at the dose prescribed. Do not share terazosin capsules with anyone else; it was prescribed only for you.
Medlineplus
Take with or without food once a day at bedtime or twice a day. Keep taking it even if you feel well and do not stop without talking to your doctor. Do not drive or do dangerous tasks for 12 hours after the first dose or a dose increase. Get out of bed slowly.
Source
https://medlineplus.gov/druginfo/meds/a693046.html
Section
How should this medicine be used? / What special precautions should I follow?
Source text (exact source wording)
Take with or without food once a day at bedtime or twice a day. Continue to take terazosin even if you feel well. Do not stop taking terazosin without talking to your doctor. Do not drive a car, operate machinery or perform dangerous tasks for 12 hours after the first time you take terazosin or after your dose is increased, and until you know how this medication affects you. To avoid this problem, get out of bed slowly, resting your feet on the floor for a few minutes before standing up.
Alternatives
Class source
Amici Pharma terazosin capsules label (DailyMed set ID 4007dbd3-e850-43e7-8a56-8735e31063cd) Description (alpha-1-selective adrenoceptor blocking agent) and MedlinePlus (alpha-blockers) https://medlineplus.gov/druginfo/meds/a693046.html
Indication source
Label INDICATIONS AND USAGE
Recommendation
none
Frequently asked questions
Question
What is terazosin used for?
Answer
Terazosin treats the symptoms of benign prostatic hyperplasia (BPH) and also treats high blood pressure.
Source section
INDICATIONS AND USAGE
Source
Amici Pharma terazosin capsules label (DailyMed set ID 4007dbd3-e850-43e7-8a56-8735e31063cd)
Question
How do I start and take terazosin?
Answer
Treatment starts with 1 mg at bedtime for everyone. For BPH the dose is raised step by step to 2 mg, 5 mg, or 10 mg once daily. For high blood pressure the usual range is 1 mg to 5 mg once a day. MedlinePlus says it can be taken with or without food.
Source section
DOSAGE AND ADMINISTRATION; MedlinePlus
Source
Amici Pharma terazosin capsules label (DailyMed set ID 4007dbd3-e850-43e7-8a56-8735e31063cd) ; https://medlineplus.gov/druginfo/meds/a693046.html
Question
What if I miss a dose?
Answer
MedlinePlus says to take it when you remember, skip it if it is almost time for the next dose, and never double up. Check with your doctor if you have missed two or more doses. If you stop for several days, the label says to restart with the initial dosing regimen.
Source section
MedlinePlus: What should I do if I forget a dose?; DOSAGE AND ADMINISTRATION
Source
https://medlineplus.gov/druginfo/meds/a693046.html ; Amici Pharma terazosin capsules label (DailyMed set ID 4007dbd3-e850-43e7-8a56-8735e31063cd)
Question
Why do I feel dizzy when I start it?
Answer
Terazosin can cause a sudden drop in blood pressure after the first dose or first few days, which can cause dizziness, lightheadedness, or fainting. Get up slowly and avoid driving or hazardous tasks for 12 hours after the first dose, a dose increase, or restarting after a break.
Source section
WARNINGS; PRECAUTIONS, Information for Patients
Source
Amici Pharma terazosin capsules label (DailyMed set ID 4007dbd3-e850-43e7-8a56-8735e31063cd)
Question
What are the common side effects?
Answer
In BPH trials the events significantly more common than placebo were asthenia, postural hypotension, dizziness, somnolence, nasal congestion or rhinitis, and impotence. Dizziness was reported by 9.1% of BPH patients and 19.3% of high blood pressure patients.
Source section
ADVERSE REACTIONS
Source
Amici Pharma terazosin capsules label (DailyMed set ID 4007dbd3-e850-43e7-8a56-8735e31063cd)
Question
Can I take it with other blood pressure medicines or erection medicines?
Answer
Use caution with other blood pressure medicines, especially verapamil, because of the chance of significant low blood pressure. Low blood pressure has also been reported with PDE-5 inhibitors. A dose change may be needed.
Source section
DOSAGE AND ADMINISTRATION, Use With Other Drugs
Source
Amici Pharma terazosin capsules label (DailyMed set ID 4007dbd3-e850-43e7-8a56-8735e31063cd)
Question
What should I tell my eye doctor?
Answer
Tell the eye surgeon you take or have taken terazosin before cataract surgery, because Intraoperative Floppy Iris Syndrome (IFIS) has been seen with alpha-1 blockers.
Source section
PRECAUTIONS, IFIS; MedlinePlus
Source
Amici Pharma terazosin capsules label (DailyMed set ID 4007dbd3-e850-43e7-8a56-8735e31063cd) ; https://medlineplus.gov/druginfo/meds/a693046.html
Question
Is it safe in pregnancy or while breastfeeding?
Answer
Safety in pregnancy has not been established and it is not recommended unless the benefit justifies the risk. It is not known whether it passes into breast milk, so caution is advised.
Source section
PRECAUTIONS, Pregnancy and Nursing Mothers
Source
Amici Pharma terazosin capsules label (DailyMed set ID 4007dbd3-e850-43e7-8a56-8735e31063cd)
Sources
- Amici Pharma terazosin capsules (primary generic label)
Set id: 4007dbd3-e850-43e7-8a56-8735e31063cd · Label effective or revised date: Rev. 03/2026 (manufacturer revision in label body); also 'Revised: 5/2026' at the end of the DailyMed label · Dailymed version date: May 21, 2026 (DailyMed publish date) · Fetched at: 2026-11-03 · Sections used: entire label via get_page_text (first 50,000 of 54,564 characters; remainder was package and product data) - Jubilant Cadista terazosin capsules (alternate 1)
Set id: 43e92495-2cf2-46dd-a80c-f0c3c88c7b73 · Label effective or revised date: Revised 07/2025 and Rev. 12/25 in label body; 'Revised: 5/2026' at the end of the DailyMed label · Dailymed version date: May 06, 2026 · Fetched at: 2026-11-03 · Sections used: revised dates only - Apnar Pharma terazosin capsules (opened, not usable)
Set id: 619dd5cb-46fb-4ad9-a05f-f064261a636b · Label effective or revised date: Revised: 8/2026 · Dailymed version date: Aug 10, 2026 · Fetched at: 2026-11-03 · Sections used: none: page is an unclassified package-label stub (about 6,500 characters) with no full label text - MedlinePlus Terazosin
Label effective or revised date: Last Revised - 12/15/2025 · Fetched at: 2026-11-03 · Sections used: all patient sections - DailyMed SPL list (terazosin)
Fetched at: 2026-11-02 · Sections used: set IDs and publish dates - openFDA label API
Fetched at: 2026-11-03 · Sections used: class query returned NOT FOUND
Information is taken from the cited sources and is for general reference only. It is not medical advice. Report side effects to FDA MedWatch at 1-800-FDA-1088. For a poison emergency call 1-800-222-1222. See prices for this drug