Antihistamine (eye drop)

Medication Information Leaflet

What are antihistamine eye drops for?

Antihistamines are a group of medications which can be used to relieve symptoms of allergic reactions. Antihistamine eye drops are used to treat symptoms of eye allergies (allergic conjunctivitis), such as red, itchy eyes and watery eyes. They may contain ingredients such as:

  • Ketotifen
  • Olopatadine
  • Pheniramine

How should I use these medications?

Apply this medication to the affected eye once or twice a day as directed by your healthcare professional.

For proper use of eye drop:

  • Wash your hands with soap and water, and read the instructions on the label.
  • Shake the bottle.
  • Tilt your head backwards and look up.
  • Gently pull the lower eyelid down to form a pocket and squeeze the bottle to apply one drop into your eye. To prevent the tip of the bottle from getting dirty, make sure the tip does not touch the eye or any other surface.
  • Close your eyes and press down gently on the inner corner of your eye for 1 to 2 minutes to allow the medicine to be absorbed and prevent it from being drained into the back of your throat.
  • If you need to use more than 1 drop of medicine, or if you are using another type of eye drop, wait at least 5 to 10 minutes before applying the next eye drop. This is to prevent the first drop of medicine from being washed away by the second drop of medicine before it has time to work. This also prevents any interactions between different eye drops.
  • If your doctor prescribed both eye drops and eye ointments, you should use the eye drops first.

For contact lens wearers:

  • Remove your contact lens before each application of medication.
  • If you are using hard lens, you can put them on directly after applying the eye drops.
  • If you are using soft lens, you can put them on 30 minutes after applying the eye drops. Otherwise, your lens may be damaged by the preservatives present in the eye drops.

What should I do if I forget to use these medications?

Antihistamine eye drops may be used when required for a short period of time. This means that you do not have to use them if you do not have any symptoms. If you miss a dose, apply it as soon as you remember. However, if it is almost time for your next dose, skip the missed dose and continue normally. Do not apply two doses or extra medication to make up for the missed dose.

What precautions should I take when using these medications?

Inform your healthcare professional if:

  • You are allergic to antihistamine eye drops or any other ingredients used in these medications
  • You are pregnant, planning to become pregnant, or breastfeeding

What are some common side effects of these medications?

  • Headache, blurred vision

These effects are mild and will subside after some time. Do not drive or operate machinery immediately after using the eye drops.

  • Burning, stinging, redness or irritation of the eye

If the discomfort continues for more than a few minutes, discontinue the medication, and rinse the affected eye with normal saline eye wash.

These side effects are usually mild and go away after some time. However, if the symptoms are bothersome, do not go away or become worse, stop these medications and consult your healthcare professional.

What are some rare but serious side effects that I need to see a doctor immediately?

The symptoms of a drug allergy include one or more of the following:

  • Swollen face/eyes/lips/tongue
  • Difficulty in breathing
  • Itchy skin rashes over your whole body

Signs that your condition may require further medical attention include:

  • Pain in the eye
  • Sensitivity to light
  • Change in vision
  • Gritty, sandy sensation in the eye
  • Discharge or mucus coming from the eye
  • Symptoms persist after self-treatment 

If you experience any of these symptoms, you should stop these medications and see your doctor immediately.

What should I avoid when I use these medications?

To avoid eye irritation, remove the contact lens prior to application of the eyedrops and wait at least 30 minutes before re-inserting the soft contact lens.

How should I store these medications?

Store in a cool and dry place, away from direct sunlight. Keep this medication away from children.

How do I throw these medications away safely?

Eye drops should be discarded 4 weeks after first opening, unless stated otherwise by the manufacturer.

Pack these medications into a black trash bag and seal it tightly before throwing it into the rubbish chute or bin. 



This article is jointly developed by members of the National Medication Information workgroup. The workgroup consists of cluster partners (National Healthcare Group, National University Health System and SingHealth), community pharmacies (Guardian, Unity and Watsons) and Pharmaceutical Society of Singapore. The content does not reflect drug availability and supply information in pharmacies and healthcare institutions. You are advised to check with the respective institutions for such information.

The information above is solely for informational purposes only and is not intended as a substitute for the advice provided by your physician, pharmacist or other healthcare professional. You should not use the information for diagnosing or treating a health problem or disease, or prescribing any medicine or other treatment. Always speak with your physician, pharmacist or other healthcare professional before taking any medicine or supplement, or adopting any treatment for a health problem. Under no circumstances will the National Medication Information workgroup be liable to any person for damages of any nature arising in any way from the use of such information.

Last updated on October 2023

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