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Generic Name: Cyproheptadine hydrochloride
Product Name: Periactin


Periactin is used to relieve the allergic symptoms for example runny nose, sneezing, hayfever and itchy and water eyes.  It also helps to relieve itch caused by mild reactions to chicken pox and insect bites and skin problems such as rash, hives, dermatitis, and eczema. Periactin is also used to treat anaphylactic reactions when other standard measures have been attempted and acute symptoms have ceased.
Periactin is rarely used to treat migraines and other headaches, in patients who still do not experience relief from other medications.

Your doctor may have prescribed Periactin for another reason. Ask your doctor if you have any questions about why Periactin has been prescribed for you.


Periactin is an antihistamine which works by blocking the action of histamine and other substances produced by the body, which causes symptoms of allergy or itchiness.

Dose advice

You should follow all instructions given by your doctor or pharmacist carefully

 For allergies and itching:

  • Adults: The usual starting dose is one tablet three times a day. Depending on your response, the dose may need to be changed. Do not take more than 8 tablets a day.
  • Children (7 to 14 years old): The usual starting dose is one tablet three times a day. Depending on your response, the dose may need to be changed. If an additional dose is required, it should be given at bedtime. Do not give more than 4 tablets a day.
  • Children (2 to 6 years old): The usual starting dose is half a tablet two to three times a day. Depending on your response, the dose may need to be changed. If an additional dose is required, it should be given at bedtime. Do not give more than 3 tablets a day.

For migraines and vascular types of headaches:

  • The usual starting dose is one tablet. This can be repeated in half an hour if needed. Do not take more than two tablets in a 4 to 6 hour period.  Relief from the migraine usually starts with two doses and is maintained with one tablet every 4 to 6 hours.
  • This medication may cause drowsiness. Do not to drive or operate machinery if this occurs.
  • Periactin increases the effect of alcohol. You should avoid alcohol and other medication that may cause sedation
  • You should inform your doctor or health professional if you are taking any other medicines, including those that are obtained without a prescription.
  • You should not be taking medicines used to treat anxiety or to help you sleep as Periactin may affect these medicines.

If you have any queries as to how to take Periactin, please ask your healthcare professional.


Schedule 3

Common side effects

All medicines have side effects. Most commonly the side effects are minor however some can be more serious. Usually the benefits of taking a medication outweigh the associated side effects. Your Doctor would have considered these side effects before starting you on Periactin.

Common side effects are those which occur in more than 1% of patients given Periactin. These include;

  • Difficulty working or thinking as a result of:
    • drowsiness, sleepiness, tiredness, sedation
    • dizziness, headache
    • restlessness, nervousness, irritability
    • excitation (especially in children)
    • buzzing or ringing in the ears
    • confusion
    • Difficulty sleeping
    • aggressive behaviour

Sleepiness and drowsiness often go away after the three or four days of taking Periactin. If you are above 65 years of age you are more likely to feel dizzy, drowsy and lightheaded.

  • stomach or bowel problems
    • nausea, vomiting
    • upset stomach
    • increased or loss of appetite, weight gain
    • diarrhoea, constipation
  • changes in your sight or taste such as:
    • blurred vision
    • dry mouth, nose and throatdisturbed co-ordination, tremor or shaking
    • excessive perspiration or sweating
    • early periods in women

Uncommon side effects

Side effects which occur in less than 1% of patients given Periactin are considered uncommon. Patients do not necessarily experience any of these side effects do not become alarmed by this list:

  • fast or irregular heart beats, also known as palpitations
  • skin rash, pinkish, itchy swellings on the skin, also known as hives 
  • yellowing of the skin and/or eyes, also known as jaundice
  • seeing, feeling or hearing things that are not there
  • frequent and/or severe infections such as fever, severe chills, sore throat or mouth ulcers
  • Numbness or tingling of the hands or feet
  • nose bleeds, bleeding or bruising more easily than normal
  • signs of anaemia, for instance looking pale, tiredness, being short of breath passing urine frequently, difficulty passing urine
  • spinning sensation, also known as vertigo

If you experience any of the listed side effects or any other symptoms which appear abnormal or unusual please tell your doctor.


  1. Australian Medicines Handbook 2007, Adelaide, Pharmaceutical Society of Australia, 2007.
  2. MIMS Online. [Monograph online] MIMS Australia Pty Ltd 2003. [Cited June 14, 2008]. Available from: [URL Link]

For further information talk to your doctor.

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Posted On: 22 July, 2003
Modified On: 24 June, 2008
Reviewed On: 23 June, 2008


Created by: myVMC