Decongestant medication - Side effects of decongestants

Decongestant medicines don't often cause side effects, and any side effects you may have are likely to be mild.

Reported side effects of decongestants include:

  • irritation to the lining of your nose
  • a skin rash
  • headaches
  • feeling sick or being sick
  • dry mouth
  • restlessness or anxiety
  • tremor (uncontrollable shaking and trembling)
  • problems sleeping (insomnia)
  • rapid and/or irregular heartbeat
  • noticing your heart beating inside your chest (palpitations)
  • in men – difficulty passing urine

These side effects should pass once you finish taking the medication.

More serious and rarer side effects include:

  • hallucinations (seeing and hearing things that are not really there)
  • experiencing a combination of vomiting, palpitations and headache – this could be due to a sudden rise in blood pressure

If you experience these rarer side effects, stop taking the medication and seek medical advice.

Very rarely you may experience a serious allergic reaction (anaphylaxis), such as swelling of the throat, that can cause breathing difficulties, as well as swelling of the lips and the appearance of a red skin rash.

Anaphylaxis is a medical emergency. Call 999 immediately and ask for an ambulance.

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