NZ Formulary

Clonidine (tablet)


What does it do?

Clonidine is used to treat high blood pressure, severe pain, and sometimes other conditions.

How should you take it?

Take clonidine tablets regularly as directed with a glass of water.

What if you forget a dose?

Take the missed dose as soon as you remember. If it is close to the time for your next dose, skip the missed dose and carry on as normal. Do not take two doses at the same time.

Can you take other medicines?

Some medicines available without a prescription may react with clonidine including:

  • anti-inflammatories, such as diclofenac (e.g. Voltaren®), ibuprofen (e.g. Nurofen®), or aspirin (e.g. Disprin®, in doses used for pain relief). These can also be found in some cold and flu medicines (e.g. Nurofen Cold and Flu®).

Tell your pharmacist or doctor about all medicines or treatments that you may be taking, including vitamins, herbal products or recreational drugs.

What side effects might you notice?

Side EffectsRecommended action

Slow heartbeat

Tell your doctor immediately

Drowsiness, dizziness, tiredness or weakness, headache

Dry mouth, nausea, vomiting, constipation

Low mood

Changes in sexual function

Joint, muscle or bone aches and pains

Tell your doctor if troublesome

Lightheaded or dizzy after standing up

Stand up slowly. If it continues, or is severe, tell your doctor

If you notice any other effects, discuss them with your doctor or pharmacist.

Other information:

  • Tell your doctor if you have heart or kidney problems, diabetes, or depression.
  • Tell your doctor if you are pregnant, planning to become pregnant, or breastfeeding.
  • Do not stop taking clonidine without talking to your doctor as this may cause a sudden increase in your blood pressure.
  • Clonidine may make you dizzy or sleepy and make it dangerous to drive, operate machinery or do other activities that require you to be alert. Limit alcohol intake because it can increase these effects.