USA Today reports that a woman has been arrested after she allegedly poisoned her husband with eye drops. The South Carolina man died after Lana Sue Clayton supposedly put eye drops in his drink. She has been arrested and charged with malicious tampering of food. Autopsy results showed that Stephen Clayton died due to poisonous levels of tetrahydrozoline, which is found in over-the-counter eye drops.

Clayton, 52, told police she put the drops in Stephen’s drink between July 19 and 21.

The drug in question can cause comas, breathing difficulty, blurred vision and seizures. If a child swallows just 1-2 milliliters of the liquid they can suffer “serious adverse events,” according to the U.S. National Library of Medicine. Tetrahydrozoline is used in both eye drops and nasal sprays to reduce redness.

Stephen died at home on July 21. Motive is unclear for the poisoning.

*Photo credit York County Sheriff’s Office