How Do BPH Alpha Blockers Work?

Benign prostatic hyperplasia (BPH) alpha-blockers are medications used to treat urinary symptoms associated with BPH and to reduce blood pressure in people with hypertension. BPH alpha blockers relax the smooth muscles in the bladder neck and prostate, and the smooth muscles around arteries and veins.

BPH alpha blockers relax the prostate and bladder neck muscles by blocking alpha1 adrenoreceptors, protein molecules that stimulate muscle contraction when activated by the hormones, epinephrine, and norepinephrine. Some BPH alpha-blockers selectively block alpha1A receptors, a subtype that is predominant in the prostate.

Most of the alpha1 receptors are located on the smooth muscles of the prostate, and vascular smooth muscles in the skin, sphincter muscles in the gastrointestinal system, kidney, and brain. Blocking alpha1 receptors improves urine flow, reduces the urinary symptoms associated with prostate enlargement, and lowers blood pressure.

BPH alpha-blockers are administered as oral tablets or capsules for the treatment of the following conditions:

FDA-approved:

• Benign prostatic hyperplasia (BPH)
• Hypertension

Off-label:

• Bladder outlet obstruction
• Ureteral stones, to facilitate kidney stone expulsion

Side effects of BPH alpha-blockers may include the following:

• Dizziness
• Fatigue
• Headache
• Retrograde ejaculation
• Abnormal ejaculation
• Impotence
• Orthostatic hypotension (drop in blood pressure when standing up from sitting or lying down)
• Vertigo
• Rhinitis (inflammation of the nasal passage)
• Nasal congestion
• Bronchitis (inflammation of the bronchial passage)
• Pharyngitis (inflammation of the throat)
• Nasopharyngitis (inflammation of nose and throat)
• Sinusitis (inflammation of the sinuses)
• Upper respiratory tract infection
• Dyspnea (shortness of breath)
• Aggravation of bronchospasm
• Cough
• Epistaxis (nasal bleeding)
• Edema
• Arthralgia (joint pain)
• Myalgia (muscle pain)
• Muscle cramps
• Muscle weakness
• Back pain
• Flu-like syndrome
• Malaise
• Infection
• Asthenia (weakness)
• Lightheadedness
• Postural dizziness
• Somnolence (drowsiness)
• Abdominal pain and discomfort
• Constipation
• Dyspepsia (indigestion)
• Nausea
• Diarrhea
• Vomiting
• Gastrointestinal obstruction
• Anorexia (loss of appetite)
• Flushing, hot flushes
• Hypotension (low blood pressure)
• Syncope (fainting)
• Chest pain
• Angina pectoris in patients with pre-existing coronary artery disease
• Palpitations
• Cardiac arrhythmias (irregular heart rhythms)
• Tachycardia (rapid heartbeat)
• Bradycardia (slow heartbeat)
• Atrial fibrillation
• Myocardial infarction (heart attack)
• Cerebrovascular accidents
• Anxiety
• Agitation
• Nervousness
• Insomnia
• Bitter taste
• Dry mouth
• Amblyopia (lazy eye)
• Blurred vision
• Visual impairment
• Intraoperative floppy iris syndrome (IFIS), a condition in which the pupils do not dilate normally, after cataract and glaucoma surgery in people on alpha1 blocker therapy
• Decreased libido
• Priapism (prolonged erection)
• Gynecomastia (breast tissue growth in males)
• Hypoesthesia (reduced skin sensation)
• Paresthesia (abnormal skin sensation)
• Hypersensitivity reactions such as:
  • Skin rash
  • Urticaria (hives)
  • Pruritus (itching)
  • Alopecia (hair loss)
  • Erythema multiforme (round lesions like a bullseye)
  • Exfoliative dermatitis (skin inflammation with redness and peeling of the skin)
  • Stevens-Johnson syndrome (a rare medical emergency with flu-like symptoms and a painful rash)
  • Toxic epidermal necrolysis (a severe skin condition with widespread redness, skin cell death, and exfoliation which can lead to sepsis)
  • Angioedema (swelling in the tissue under the skin or mucous membranes)
  • Respiratory symptoms
• Liver injury and impaired liver function
• Jaundice
• Abnormal liver function tests
• Hepatitis (liver inflammation)
• Blood disorders such as:
  • Leukopenia (low count of leukocytes, type of immune cells)
  • Thrombocytopenia (low platelet count in the blood)
  • Purpura (purple spots on skin from small blood vessels bursting under the skin)
• Hematuria (blood in urine)
• Micturition (urination) disorder
• Micturition frequency
• Nocturia (frequent nighttime urination)
• Polyuria (excessive urinary output)

Information contained herein is not intended to cover all possible side effects, precautions, warnings, drug interactions, allergic reactions, or adverse effects. Check with your doctor or pharmacist to make sure these drugs do not cause any harm when you take them along with other medicines. Never stop taking your medication and never change your dose or frequency without consulting your doctor.

Generic and brand names of BPH alpha-blocker drugs include:

• alfuzosin
• Cardura
• Cardura XL
• doxazosin
• Flomax
• Rapaflo
• silodosin
• tamsulosin
• terazosin
• UroXatral