[12] In a healthy person, the biological half-life of tetryzoline is approximately 6 hours, and it is excreted in urine, chemically unchanged, at least in part.

[3] An urban legend suggests that tetryzoline can cause violent diarrhea if given orally, such as by putting a few drops of Visine in an unsuspecting person's beverage.

[13] In late August 2018, a South Carolina woman was charged with murdering her husband by putting eye drops containing tetryzoline in his drinking water.

[14][15][16] Tetryzoline has been used as a date rape drug in a number of cases due to its ability to cause dizziness and unconsciousness.

[9] In 2018, a 62 year-old woman in Pewaukee, Wisconsin, died in an apparent overdose or suicide involving tetryzoline and other substances; in November 2023 her caregiver was convicted of first-degree murder, following the allegation that her death was caused by a water bottle laced with Visine.

[17][18] In 2019, a North Carolina paramedic was accused of using tetryzoline eye drops to cause the death of his wife.

[19][20] In the 9-1-1 Season 4 Episode 13 Suspicion, a mother, Sheila, poisons her son, Charlie, with tetryzoline eye drops by putting it into his food to make him seem sick and gain donations as a form of Munchausen syndrome by proxy.