Terazosin: uses, appearance and warnings

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.

Terazosin Capsules, USP are available as: 1 mg: White capsules imprinted AP 781 in black ink, filled with white powder are supplied as follows: NDC 87564-081-10 bottle of 100 capsules with child-resistant closure NDC 87564-081-01 bottle of 1000 capsules with child-resistant closure 2 mg: Yellow capsules imprinted AP 782 in black ink, filled with white powder are supplied as follows: NDC 87564-082-10 bottle of 100 capsules with child-resistant closure NDC 87564-082-01 bottle of 1000 capsules with child-resistant closure 5 mg: Pink capsules imprinted AP 783 in black ink, filled with white powder are supplied as follows: NDC 87564-083-10 bottle of 100 capsules with child-resistant closure NDC 87564-083-01 bottle of 1000 capsules with child-resistant closure 10 mg: Aqua capsules imprinted AP 784 in black ink, filled with white powder are supplied as follows: NDC 87564-084-10 bottle of 100 capsules with child-resistant closure NDC 87564-084-01 bottle of 1000 capsules with child-resistant closure 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. To report SUSPECTED ADVERSE REACTIONS, contact Amerisyn, LLC at 336-907-8990 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. Dispense with Medication Guide available at: www.amerisyn.us/products/ Rx only Manufactured for: Amerisyn, LLC Greensboro, NC 27410 Code. 300193 Rev. 08/2026

Terazosin capsules are contraindicated in patients known to be hypersensitive to terazosin hydrochloride.

Syncope and "First-dose" Effect 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. Syncope has also been reported with other alpha-adrenergic blocking agents in association with rapid dosage increases or the introduction of another antihypertensive drug. Syncope is believed to be due to an excessive postural hypotensive effect, although occasionally the syncopal episode has been preceded by a bout of severe supraventricular tachycardia with heart rates of 120 to 160 beats per minute. Additionally, the possibility of the contribution of hemodilution to the symptoms of postural hypotension should be considered. 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. Dosage should then be increased slowly, according to recommendations in the Dosage and Administration section and additional antihypertensive agents should be added with caution. 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 early investigational studies, where increasing single doses up to 7.5 mg were given at 3 day intervals, tolerance to the first dose phenomenon did not necessarily develop and the "first-dose" effect could be observed at all doses. Syncopal episodes occurred in 3 of the 14 subjects given terazosin capsules at doses of 2.5, 5 and 7.5 mg, which are higher than the recommended initial dose; in addition, severe orthostatic hypotension (blood pressure falling to 50/0 mmHg) was seen in two others and dizziness, tachycardia, and lightheadedness occurred in most subjects. These adverse effects all occurred within 90 minutes of dosing. In three placebo-controlled BPH studies 1, 2, and 3 (see CLINICAL PHARMACOLOGY ), the incidence of postural hypotension in the terazosin capsules, treated patients was 5.1%, 5.2%, and 3.7% respectively. In multiple dose clinical trials involving nearly 2000 hypertensive patients treated with terazosin capsules, syncope was reported in about 1% of patients. Syncope was not necessarily associated only with the first dose. If syncope occurs, the patient should be placed in a recumbent position and treated supportively as necessary. There is evidence that the orthostatic effect of terazosin capsules is greater, even in chronic use, shortly after dosing. The risk of the events is greatest during the initial seven days of treatment, but continues at all time intervals. Priapism 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 ).

Benign Prostatic Hyperplasia The incidence of treatment-emergent adverse events has been ascertained from clinical trials conducted worldwide. All adverse events reported during these trials were recorded as adverse reactions. The incidence rates presented below are based on combined data from six placebo-controlled trials involving once-a-day administration of terazosin capsules at doses ranging from 1 to 20 mg. 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. 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. …

In controlled trials, terazosin capsules have been added to diuretics, and several beta-adrenergic blockers; no unexpected interactions were observed. 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. Terazosin capsules have been used concomitantly in at least 50 patients on the following drugs or drug classes: 1. analgesic/anti-inflammatory (e.g., acetaminophen, aspirin, codeine, ibuprofen, indomethacin); 2. antibiotics (e.g., erythromycin, trimethoprim and sulfamethoxazole); 3. anticholinergic/sympathomimetics (e.g., phenylephrine hydrochloride, phenylpropanolamine hydrochloride, pseudoephedrine hydrochloride); 4. antigout (e.g., allopurinol); 5. antihistamines (e.g., chlorpheniramine); 6. …