The incidence of adverse reactions was derived from clinical trials involving 1,986 hypertensive patients on terazosin monotherapy or combination therapy.
The most serious adverse reaction encountered with terazosin hydrochloride is syncope occurring in approximately 1% of patients.
The most common reactions were dizziness (18.9%), headache (14.1%), asthenia (11%), somnolence (4.8%), nasal congestion (4.6%) and palpitation (4.6%).
The most frequently reported adverse effects which resulted in termination of terazosin hydrochloride were dizziness (3.5%), asthenia (2.1%) and headache (1.8%).
The following events were reported in less than 1% of cases except as indicated in brackets. The order of presentation corresponds within each heading to the relative frequency of occurrence.
Body as a Whole:
Headache (14.1%), asthenia (11%), peripheral edema (3.6%), chest pain (2.2%), abdominal pain (1.5%), edema (1.3%), facial edema (1.0%), back pain, weight gain, allergic reactions, malaise.
Palpitation (4.6%), tachycardia (2.9%), syncope (1%), postural hypotension, angina pectoris, arrhythmias, cerebrovascular accident, heart failure, hypotension (at times severe), migraine.
Nausea (3.9%), dry mouth (1.7%), diarrhea (1.3%), dyspepsia, vomiting, anorexia, gastritis, liver function abnormality, jaundice.
Dizziness (18.9%), somnolence (4.8%), nervousness (2.2%), paresthesia (1.5%), insomnia (1.2%), incoordination, abnormal dreams, confusion, speech disorder, tremor, vertigo, seizure, depression.
Nasal congestion (4.6%), dyspnea (2.8%), rhinitis (1.2%), sinusitis, cold symptoms, pharyngitis, asthma, increased cough, laryngeal spasm.
Skin and Appendages:
Sweating (1.1%), pruritus, rash, photosensitivity.
Blurred vision (1.4%), eye disorder (1.2%), tinnitus, taste perversion.
Impotence (1.1%), urinary frequency, dysuria.
Pain in extremities (1.8%), hypokalemia, hypophosphatemia, decreased libido.
At least two cases of severe anaphylactoid reactions were reported to be associated with administration of terazosin hydrochloride (see Warnings).
Post-Marketing Experience: Body as a whole:
Fever, neck pain, and shoulder pain.
Vasodilation and atrial fibrillation have been reported; however, a cause and effect relationship has not been established.
Constipation and flatulence.
Bronchitis, epistaxis and flu symptoms.
Priapism, urinary tract infection, and urinary incontinence primarily reported in post-menopausal women.
Arthralgia, arthritis, joint disorder, and myalgia.
Thrombocytopenia has been reported.
Benign Prostatic Hyperplasia:
In clinical trials involving 1,171 patients with BPH, syncope was reported in 0.7% of patients following treatment with terazosin hydrochloride.
The most common reactions (≥1%) were dizziness (14.0%), asthenia (9.0%), headache (6.4%), somnolence (4.5%), postural hypotension (3.8%), impotence (3.5%), urinary tract infection (3.1%), pharyngitis (2.7%), dyspnea (2.5%), rhinitis (2.2%), dysuria (2%), back pain (1.8%), nausea (1.8%), flu syndrome (1.7%), rash (1.7%), sinusitis (1.7%), hypotension (1.5%), chest pain (1.5%), vertigo (1.3%), dyspepsia (1.1%), diarrhea (1%), palpitation (1%), abdominal pain (1%) and amblyopia (1.0%).
Thrombocytopenia has been reported. Atrial fibrillation has been reported; however, a cause and effect relationship has not been established. Priapism has also been reported.