Clinical trials were conducted on more than 900 patients.
During these trials and subsequent marketing experience, the most frequent
reactions associated with MINIPRESS therapy are: dizziness 10.3%, headache
7.8%, drowsiness 7.6%, lack of energy 6.9%, weakness 6.5%, palpitations 5.3%,
and nausea 4.9%. In most instances, side effects have disappeared with
continued therapy or have been tolerated with no decrease in dose of drug.
Less frequent adverse reactions which are reported to
occur in 1-4% of patients are:
Gastrointestinal: vomiting, diarrhea,
Cardiovascular: edema, orthostatic hypotension,
Central Nervous System: vertigo, depression,
Genitourinary: urinary frequency.
EENT: blurred vision, reddened sclera, epistaxis,
dry mouth, nasal congestion.
In addition, fewer than 1% of patients have reported the
following (in some instances, exact causal relationships have not been
Gastrointestinal: abdominal discomfort and/or
pain, liver function abnormalities, pancreatitis.
Central Nervous System: paresthesia,
Dermatologic: pruritus, alopecia, lichen planus.
Genitourinary: incontinence, impotence, priapism.
Other: diaphoresis, fever, positive ANA titer,
Single reports of pigmentary mottling and serous
retinopathy, and a few reports of cataract development or disappearance have
been reported. In these instances, the exact causal relationship has not been established
because the baseline observations were frequently inadequate.
In more specific slit-lamp and funduscopic studies, which
included adequate baseline examinations, no drug-related abnormal
ophthalmological findings have been reported.
Literature reports exist associating MINIPRESS therapy
with a worsening of pre-existing narcolepsy. A causal relationship is uncertain
in these cases.
In post-marketing experience, the following adverse
events have been reported:
Autonomic Nervous System: flushing.
Body As A Whole: allergic reaction, asthenia,
Cardiovascular, General: angina pectoris,
Heart Rate/Rhythm: bradycardia.
Vascular (Extracardiac): vasculitis.
Vision: eye pain.
Special Senses: 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).