Antihistamines are a type of medication that treats allergy symptoms. Some antihistamines can cause the eyes to produce fewer tears, which can cause or worsen dry eye syndrome.
Dry eye occurs when the eye does not produce enough tears. Oral antihistamines are one
Researchers have found popular oral antihistamines, such as diphenhydramine,
This article looks at antihistamine options that are less likely to cause or worsen dry eyes. It then discusses how antihistamines can cause dry eyes or worsen dry eye syndrome and ways to relieve dry eyes.
People with dry eye syndrome may benefit from using antihistamines in the form of eye drops.
Types of antihistamines in eye drop form include:
- Ketotifen (Zaditor): These eye drops combine antihistamines, which relieve itchiness, and mast-cell stabilizers. Mast-cell stabilizers help prevent eye allergies.
- Epinastine (Elestat): This medication also contains antihistamines and mast cell stabilizers.
- Alcaftadine (Lastacaft): Alcaftadine treats allergic conjunctivitis, which occurs when the eye comes into contact with allergens.
- Emedastine (Emadine): These are antihistamines in eye drop form.
- Azelastine (Optivar): These are antihistamines in eye drop form and are also available as a nasal spray.
Oral antihistamines
When a person encounters an allergen, the immune system releases the chemical called histamine, which binds to certain cell receptors.
When histamines bind to receptors, they trigger various allergic reactions, such as a runny nose and watery, itchy eyes.
Antihistamines block H1 histamine receptors on mast cells and treat certain allergy symptoms. While older, first-generation oral antihistamines may reduce symptoms, such as watery eyes and runny nose, they may also
This can lead to the development of dry eyes or worsen symptoms in those with dry eye syndrome.
There are various potential causes of dry eyes. These include:
- being in a smoky, dry, or windy environment
- using contact lenses for a prolonged period
- looking at a screen for a long time
- having laser eye surgery
- certain diseases, such as lupus, rheumatoid arthritis, and thyroid disease
- taking certain medications, such as antidepressants, diuretics, and beta-blockers
- ectropion, which is when the eyelids turn outward
- entropion, which is when the eyelids turn inward
- blepharitis, which refers to red, swollen eyelids
A doctor or pharmacist may be able to suggest an alternative allergy treatment, such as second-generation oral antihistamines or newer antihistamine eye drops, or provide a supplemental treatment for dry eyes, such as lubricating eye drops.
If another type of medication is the cause of a person’s dry eyes, a person can discuss this side effect with a doctor.
A doctor could suggest an alternative or provide a treatment for dry eyes. It is important that a person does not stop taking prescribed medication without discussing it with a healthcare professional.
There are several ways someone may find relief from dry eye. These include lifestyle changes and medical treatments.
Lifestyle adjustments
A person
- limiting screen time
- avoiding windy, dry, and smoky environments
- drinking 8–10 glasses of water a day
- wearing wraparound sunglasses while outside
- using a humidifier indoors
- sleeping 7–8 hours a night
Medical treatments
Treatments for dry eyes
- over-the-counter (OTC) eye drops, such as artificial tears and lubricating ointments
- prescription medications that can increase tear production, such as cyclosporine (Restasis)
- tear duct plugs, which are special plugs that a person can insert in the tear ducts to prevent tear drainage
- surgery on the eyelids to prevent tears from draining too quickly
A person needs to contact a doctor if their dry eyes do not respond to lifestyle changes or OTC treatment.
If an individual does not receive treatment and the condition becomes severe, dry eyes may cause persistent eye discomfort. They
Antihistamines help treat certain allergy symptoms by blocking H1 histamine receptors. However, while they may improve symptoms such as a runny nose, some oral antihistamines may also significantly reduce tear volume.
A reduction in tear volume can lead to dry eye, which can affect vision and leave the eyes dry and irritated. Oral antihistamines can exacerbate dry eyes in people with dry eye syndrome or cause someone to develop it.
A person can take antihistamines in the form of eye drops instead of orally, which may reduce the risk of dry eye as a side effect.