Doxazosin (Doxazosin 4mg modified-release tablets)

Side effects

Information specific to: Doxazosin 4mg modified-release tablets when used in High blood pressure.


A medicine is only made available to the public if the clinical trials have shown that the benefits of taking the medicine outweigh the risks.

Once a medicine has been licensed, information on the medicine's effects, both intended and unintended, is continuously recorded and updated.

Some side-effects may be serious while others may only be a mild inconvenience.

Everyone's reaction to a medicine is different. It is difficult to predict which side-effects you will have from taking a particular medicine, or whether you will have any side-effects at all. The important thing is to tell your prescriber or pharmacist if you are having problems with your medicine.

Common: More than 1 in 100 people who take Doxazosin mesilate

  • a drop in blood pressure on standing or sitting up. This may cause feelings of faintness, dizziness, or tiredness. If you develop any of these symptoms you should lie down until you have recovered
  • back pain
  • breathing difficulties
  • bronchitis
  • chest pain
  • cough
  • cystitis
  • dry mouth
  • faster heart rate
  • feeling dizzy
  • flu or flu-like symptoms
  • headaches
  • indigestion
  • itching
  • lowered blood pressure
  • muscle pain or tenderness
  • nausea
  • oedema of the extremities
  • palpitations
  • respiratory tract infection
  • rhinitis
  • sleepiness
  • stomach pain
  • urinary incontinence
  • urinary tract infection
  • vertigo
  • weakness

Uncommon: More than 1 in 1000 people who take Doxazosin mesilate

  • abnormal laboratory test results
  • allergic reactions
  • angina
  • appetite gain
  • blood in the urine
  • constipation
  • depression
  • diarrhoea
  • difficult or painful urination
  • difficulty sleeping
  • facial oedema
  • fainting or brief loss of consciousness
  • feeling anxious
  • flatulence
  • gastroenteritis
  • gout
  • heart attack
  • hypoaesthesia
  • impotence
  • joint pain
  • loss of appetite
  • nose bleed
  • pain
  • skin rash or rashes
  • stroke
  • tinnitus
  • tremors
  • urinating more often
  • vomiting
  • weight gain

Very rare: Fewer than 1 in 10,000 people who take Doxazosin mesilate

  • blood problems
  • blurred vision
  • breast enlargement in men
  • bronchospasm
  • feeling agitated
  • feeling nervous
  • flushing
  • gallbladder problems
  • general feeling of being unwell
  • hair loss
  • heart problems
  • jaundice
  • liver problems
  • muscle cramps
  • muscle weakness
  • paraesthesiae
  • passing much more urine than usual
  • priapism
  • slower heart rate
  • tiredness
  • unexplained or easy bruising of the skin or mucous membranes
  • urinary problems
  • urinating more often at night
  • urticaria

The frequency of these side-effects is unknown

  • complications during cataract surgery
  • ejaculation problems

If you feel unwell or if you have concerns about a side-effect, you will need to seek advice. If you feel very ill, get medical help straight away. Contact your prescriber, pharmacist, nurse or call 111.

Content provided by Datapharm

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The Yellow card Scheme is vital in helping the MHRA monitor the safety of the medicines and vaccines that are on the market.

Before a medicine is granted a licence so that it can be made available in the United Kingdom, it must pass strict tests and checks to ensure that it is acceptably safe and effective. All effective medicines however, can cause side effects.