Terazosin Side Effects
Some side effects of terazosin may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.
For the Consumer
Applies to terazosin: oral capsule, oral capsule liquid filled, oral tablet
Along with its needed effects, terazosin may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor as soon as possible if any of the following side effects occur while taking terazosin:More common
- Chest pain
- dizziness or lightheadedness when getting up from a lying or sitting position
- fainting (sudden)
- fast or irregular heartbeat
- pounding heartbeat
- shortness of breath
- swelling of feet or lower legs
- Weight gain
Some side effects of terazosin may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:More common
- unusual tiredness or weakness
- Back or joint pain
- blurred vision
- nausea and vomiting
- stuffy nose
For Healthcare Professionals
Applies to terazosin: oral capsule, oral tablet
Syncope has occurred in less than 1% of patients. Palpitations have been reported in 5% of patients, but are much less likely than with some other alpha-adrenergic blockers. Peripheral edema, cold extremities, and chest pain have been reported in up to 6%, 12%, and 5% of patients, respectively. Atrial fibrillation has been reported (incidence not given).
Cardiovascular side effects have included orthostatic hypotension, which generally occurs within 30 to 60 minutes after the first dose. For this reason, it is recommended that the first dose be administered at bedtime. Other symptoms of hypotension, such as mild to moderate dizziness, lightheadedness, palpitations and weakness have occurred in 1% to 30% of patients. Some cardiovascular side effects, particularly dizziness, have been more prevalent among persons greater than 65 years old.
Ocular side effects including Intraoperative Floppy Iris Syndrome (IFIS) have been observed in some patients undergoing phacoemulsification cataract surgery while being treated with alpha-1 blockers.
Most reports were in patients treated with an alpha-1 blocker at the time IFIS occurred, but in some instances the alpha-1 blocker had been stopped prior to surgery. The manufacturer recommends that patients be questioned to determine whether or not they have taken alpha-1 blockers prior to being considered for cataract surgery. If it is determined that the patient has taken an alpha-1 blocker, the patient's ophthalmologist should be prepared for possible modifications to their surgical technique that may be necessary should IFIS be observed during the procedure.
Nervous system side effects, such as dizziness (5% to 30% of patients) and blurred vision (2% of patients) may be related to hypotension. Headaches (2% to 10%), asthenia (8%), and somnolence (6%) have occurred following long-term use.
Metabolic side effects have included decreases in serum triglycerides and VLDL cholesterol, and increases in HDL cholesterol. Terazosin may counterbalance deleterious effects on the lipid profile associated with thiazide diuretics, making it a reasonable drug to use in combination with these agents.
Musculoskeletal complaints of pain or cold extremities have been reported in up to 17% and 12% of patients, respectively.
Nasal congestion and symptoms of sinusitis or dyspnea may be due to alpha-adrenergic blockade.
Respiratory system side effects have been limited to nasal congestion in 2% to 12% of patients.
Only 4% of 354 patients from a multicenter trial complained of general abdominal pain or diarrhea within the first 90 days of therapy.
Gastrointestinal problems have been limited mainly to nausea in 5% of patients.
Genitourinary complaints have rarely included impotence and priapism.
Hypersensitivity reactions have been reported, including anaphylaxis and rashes.
In a study of 226 patients on terazosin for up to 2 years, only 2 discontinued therapy due to rash.
A 56-year-old white male developed a generalized scaling erythematous rash on the third day after starting terazosin 2 mg daily for benign prostatic hypertrophy. The rash was accompanied by mild fever, asthenia, and intense pruritus. The patient was on no other medications. Hematologic and histopathologic studies suggested a drug reaction. Terazosin was discontinued. Two weeks following oral methylprednisolone (40 mg daily) and emollients, symptoms had resolved completely.
Dermatologic side effects of skin rash have been reported rarely. Lichenoid drug eruption has been associated with terazosin therapy.
Hematologic side effects have included thrombocytopenia.
More terazosin resources
- terazosin MedFacts Consumer Leaflet (Wolters Kluwer)
- terazosin Advanced Consumer (Micromedex) - Includes Dosage Information
- Terazosin Professional Patient Advice (Wolters Kluwer)
- Terazosin Prescribing Information (FDA)
- Hytrin Prescribing Information (FDA)
- Hytrin Monograph (AHFS DI)
- Hytrin Consumer Overview
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