Stories -- some perhaps apocryphal -- abound on the Internet: A husband on a romantic holiday with his wife takes a pill from his Cialis bottle to enhance his sexual performance, but ends up falling asleep early. His wife had packed her Ambien CR in an old container.
One 50-year-old El Dorado Hills, California, woman with a clean record confesses to a driving under the influence charge after taking the wrong medicine.
"I hit an electrical pole and have sporadic recollection of events from accident to arriving at jail," she writes. "Later I discovered I had mistakenly taken Ambien instead of Zoloft [an antidepressant] at 7 am that morning. Medications are identical color and shape, but differ slightly in size. I am really shook up."
Others confuse eye drops with ear drops; allergy medicine with beta blockers. One woman said she inadvertently brushed her teeth with Preparation H.
And it's not just medications that are a problem. Myszka Watt of Worcester, Mass., left her house in a rush, grabbing what she thought was hairspray and doused her hair with Lysol.
"Unfortunately, Lysol does not act like hairspray," the 59-year-old told ABCNews.com. "It was wet and heavy. Yes, I had to start over and was very late for work."
Just last week, the FDA warned about medication errors from swallowing a topical drug: Benadryl Extra Strength Itch Stopping Gel.
The FDA had received numerous reports of "adverse events" for the drug prescribed for itchy skin. Ingesting the drug can cause dangerous levels of the active ingredient, diphenhydramine, causing unconsciousness, hallucinations and even the inability to speak.
Some of those cases were serious enough to require emergency room treatment, hospitalization or admission to the intensive care unit. And it wasn't just adults. One 26-month-old toddler was mistakenly given the Benadryl to swallow.
Packaging and assumptions about delivery of a drug can often be confusing, according to Cynthia Reilly, director of the practice development division of the American Society of Health-System Pharmacists.
"To them it looked like from past experience, a liquid would be taken orally," she said. "If it's topical, we think ointments and tubes. Calamine lotion comes in a bottle, but from a young age we know the conditions and the pink lotion."
Many consumer errors go unreported, if a patient even realizes it happened at all.
"We live in a culture with very short attention spans," she said. "At a time when we are bombarded with distractions there are an increase in therapies that are more complicated and require more attention."
Over time, pharmacists learn to be "as clear as possible," such as reminding patients to "remove the foil" before inserting a suppository, Reilly said.
Medications have also changed. Women's yeast infections are now treated orally. Ear infections no longer require oral antibiotics, but ear drops.
"People tend to have an ailment in a specific region of the body and they automatically assume they deliver it there," she said.
Neither Reilly nor Casavant is excited about new color-coded systems for prescription medications.
Before antibiotics were available for treatment of syphilis, the drug-of-the day, mercuric chloride, was so dangerous if misused, that the pills were shaped like coffins. But special packaging can make consumers lazy, according to Casavant.