What Happens When You Swallow Eye Drops?

young asian woman using eye drops

The Bottom Line

Over-the-counter anti-redness eyedrops are used to treat irritated, red eyes. When consumed by mouth, they can result in serious toxicity and even death.

bottle of eye drops next to pair of glasses

How do anti-redness eyedrops work?

Red eyes are the result of swelling of blood vessels in the conjunctiva (the membrane covering the surface of the eye and the inner eyelids). This swelling can be caused by a range of conditions, including conjunctivitis, allergies, and fatigue.

Over-the-counter anti-redness eye drops contain decongestant medications that reduce the swelling of these blood vessels. The most common decongestant medication is tetrahydrozoline, which is the active ingredient in Visine and Murine eye drops.

Are anti-redness eye drops poisonous if swallowed?

Tetrahydrozoline is similar to a commonly used blood pressure-lowering medication called clonidine. When swallowed, tetrahydrozoline can also cause sleepiness, low blood pressure, and a dangerously slow heart rate. Young children who consume small amounts of tetrahydrozoline eye drops (as little as ½ teaspoonful) can develop sleepiness and difficulty breathing. Teenagers and adults who drink larger amounts can develop heart rhythm abnormalities and breathing problems that can be life-threatening. Symptoms have been reported in cases where tetrahydrozoline eye drops reached the gastrointestinal tract by draining down tear ducts.

In 2023, 771 exposures to tetrahydrozoline eye drops were reported to US poison centers. About 40% were in children 5 years of age or younger, and about a third were treated in healthcare facilities. Despite its reputation as a gastrointestinal irritant, diarrhea is not a common side effect of tetrahydrozoline.

What to do if you drink eye drops

If you or a loved one drank eyedrops or nasal decongestant sprays by accident or on purpose, do not wait for symptoms to occur. Immediately use the webPOISONCONTROL online tool or call 1-800-222-1222. Both options are free for the public, and available 24 hours a day.

Kelly Johnson-Arbor, MD
Medical Toxicology Physician

Revised William G. Troutman, PharmD
Professor of Pharmacy Emeritus

Poisoned?

Call 1-800-222-1222 or

HELP ME online

Prevention Tips

  • Always use anti-redness eyedrops according to the package label; never drink these products.
  • Because anti-redness eye drops are often sold without child-resistant packaging, it is very important to keep these products far away from the reach of young children.
  • Anti-redness eye drops are intended for occasional use. If you need to use them often, see your eye care specialist because this might indicate a serious eye problem.

This Really Happened

A 64-year-old man was found dead in his home; the cause of death was initially presumed to be falling down a flight of stairs. When his autopsy revealed a high concentration of tetrahydrozoline in his system, investigators interviewed his wife, who admitted that she had been adding eye drops to his food to make him sick, similar to a scene in the movie, “Wedding Crashers.” The wife was convicted of voluntary manslaughter and tampering with a food or drug and is currently serving a 25-year prison sentence (from Lee, 2022).


For More Information

Gudgel DT. How to put in eye drops. American Academy of Ophthalmology. May 5, 2023. Accessed January 26, 2025.


References

Al-Abri SA, Yang HS, Olson KR. Unintentional pediatric ophthalmic tetrahydrozoline ingestion: case files of the medical toxicology fellowship at the University of California, San Francisco. J Med Toxicol. 2014;10(4):388-391.

Eddy O, Howell JM. Are one or two dangerous? Clonidine and topical imidazolines exposure in toddlers. J Emerg Med. 2003;25(3):297-302.

Lee BY. How Visine eye drops in the mouth can kill, here are two cases. Forbes. Updated April 14, 2022. Accessed January 26, 2025.

Menshawey E, Menshawey R. More than meets the eye: a scoping review on the non-medical uses of THZ eye drops. Forensic Sci Med Pathol. 2024;20(2):569-578.

Osterhoudt KC, Henretig FM. Sinoatrial node arrest following tetrahydrozoline ingestion. J Emerg Med. 2004;27(3):313-314.

Šoša I. Ingestion of fluids of the ocular surface containing eye drops of imidazole derivatives-alpha adrenergic receptor agonists as paragons. Pharmaceuticals (Basel). 2024;17(6):758.

Spiller H, Griffith J. Prolonged cardiovascular effects after unintentional ingestion of tetrahydrozoline. Clin Toxicol (Phila). 2008;46(2):171-172.

Poisoned?

Call 1-800-222-1222 or

HELP ME online

Prevention Tips

  • Always use anti-redness eyedrops according to the package label; never drink these products.
  • Because anti-redness eye drops are often sold without child-resistant packaging, it is very important to keep these products far away from the reach of young children.
  • Anti-redness eye drops are intended for occasional use. If you need to use them often, see your eye care specialist because this might indicate a serious eye problem.

This Really Happened

A 64-year-old man was found dead in his home; the cause of death was initially presumed to be falling down a flight of stairs. When his autopsy revealed a high concentration of tetrahydrozoline in his system, investigators interviewed his wife, who admitted that she had been adding eye drops to his food to make him sick, similar to a scene in the movie, “Wedding Crashers.” The wife was convicted of voluntary manslaughter and tampering with a food or drug and is currently serving a 25-year prison sentence (from Lee, 2022).