Medicines that cause dry eyes, and what to do about it

How a medicine can dry your eyes

Your tear film has three layers: mucus next to the eye, which helps tears stick; water in the middle, made by the tear gland under your upper lid; and oil on top, made by the meibomian glands along your lid edges, which stops the water drying up between blinks. A medicine can upset any of them. There are four main ways.

1. Blocking the “make tears” signal

Your tear gland is switched on by a chemical messenger called acetylcholine. Many medicines block it. Doctors call this an anticholinergic effect. It is the same effect that gives you a dry mouth, so less signal means less water in your tears.

2. Lowering tears in other ways

Water tablets lower the fluid in your body. Some blood pressure tablets seem to reduce tear flow too, though exactly how is less clear.

3. Changing the oil glands

Medicines that shrink oil glands in the skin, such as isotretinoin, shrink the meibomian glands too. Hormones affect them as well. With a thin oil layer, tears evaporate in seconds even if you make plenty of water.

4. Preservatives in eye drops

Drops in multi-use bottles contain a preservative. The most common, benzalkonium chloride, works a bit like a mild detergent. Used now and then, it is fine. Used every day for years, as glaucoma drops often are, it can irritate the surface of the eye.

Often several things add up. For the full picture, read what causes dry eyes.

Which medicines can cause dry eyes?

These are the groups most often linked with dry eye, with common UK examples. It is not a complete list, and many people take these with no eye problems at all.

The pattern to notice: if a medicine gives you a dry mouth, it is more likely to dry your eyes. Several drying medicines together add up.

Antidepressants and dry eyes

The older tricyclic antidepressants, such as amitriptyline, are the most drying. Amitriptyline is also widely used at low doses for nerve pain, headaches and sleep, so many people taking it don’t think of it as an antidepressant. SSRIs such as sertraline and citalopram are linked with dry eye too, though usually more mildly.

Please don’t stop an antidepressant because of your eyes. Stopping suddenly can cause withdrawal symptoms and bring back what it was treating. The dryness can usually be managed well while you carry on. If you want to talk about other options, your GP is the right person.

Isotretinoin, HRT and hormones

Isotretinoin

Isotretinoin shrinks the oil glands in your skin, and the oil glands in your lids shrink with them. Sore, dry eyes are common during a course. Most people improve afterwards, but for some the glands don’t fully recover and the dryness lasts. If your eyes are getting worse on it, have your glands checked rather than waiting. Contact lenses often feel worse too (see why contact lenses dry out).

HRT, the pill and other hormones

Here the evidence is honestly mixed. Sex hormones affect the oil glands, and studies of HRT disagree on whether it makes dry eye better or worse. HRT is not a dry eye treatment: don’t start or stop it for your eyes. The menopause itself causes dry eye too, so it is often hard to separate the medicine from the life stage. More in dry eyes and the menopause.

Dry eye is a known side effect of tamoxifen and of aromatase inhibitors such as anastrozole. It is treatable, and these medicines are far too important to stop.

Glaucoma drops and preservatives

If you use glaucoma drops, you may be putting a preservative on your eyes every day for years. Typical signs are red, gritty, burning eyes that got worse over months. Many glaucoma drops now come preservative-free. Ask your eye doctor or GP if one suits you.

Never stop glaucoma drops, even for a few days. Glaucoma sight loss cannot be reversed, and the drops prevent it. The same goes for preserved lubricating drops used many times a day: they can add to the problem, which is why we usually suggest preservative-free ones.

What to do in the meantime

• Use a preservative-free lubricating drop regularly, not only when it is bad, and a gel at bedtime if mornings are worst. See which eye drops suit which dry eye.
• Look after the oil glands if your eyes burn or get worse through the day. A warm compress and lid clean helps the oil flow: our simple home lid routine shows how, and drops for blocked oil glands explains which drops add oil back.
• Blink and take screen breaks. Lower tears make screen work much harder. See screens and dry eyes.
• Keep fans, car vents and heating off your face, and drink enough water, especially on water tablets.

Not sure how bad yours is? Our free 60-second dry eye check gives you a score to bring to your GP or to us.

When you don’t need us, and when you do

If a medicine is short term, such as a week of hay fever tablets, the dryness usually settles soon after you stop. A lubricating drop meanwhile is enough. You don’t need an appointment.

Come and see us if you take a drying medicine long term and your eyes feel gritty or burning most days, if drops only help briefly, if your eyes are still sore after isotretinoin, or if it affects your work, driving or sleep. When the cause is blocked oil glands, drops alone rarely sort it. See how we treat blocked oil glands, or every treatment and price on our dry eye clinic page. For what to expect long term, read does dry eye go away?