On The Side

Imagine gaining 44 pounds—because a medication you're taking causes you to binge eat while you're sleeping. It sounds strange, but it's true. In fact, many medications have unintended consequences, which should be discussed with your doctor or pharmacist. Although the risks are typically very low, the Food and Drug Administration (FDA) and/or the manufacturers of the drug admit they are possible.

While these side effects are rare, they are acknowledged as possible complications. If you have concerns about a prescription medication you’re taking, be sure to speak to your doctor about the proper steps to take.

Blindness. In response to reports of sudden blindness in men taking erectile dysfunction medications, in 2005, the FDA mandated updated labeling for drugs containing sildenafil citrate, tadalafil, or vardenafil as their active ingredients. The blindness risk was reported in June of 2005 in the Journal of Neuro-Ophthalmology, which reported seven cases of unusual sudden blindness within 36 hours of taking an erectile dysfunction drug containing sildenafil citrate. The FDA received 38 additional reports of men experiencing impaired vision after taking the drug. These cases were related to reduced blood flow to the eyes in patients who were also suffering from high blood pressure and diabetes, according to the FDA. It is most common in older people. Patients who experience sudden or decreased vision loss in one or both eyes should stop taking the medications and to contact their doctor immediately, the FDA advises.

Black Tongue. Surprisingly, this side effect is not as scary as it looks. A compound of the element bismuth called bismuth subsalicylate has properties that have antidiarrheal, antibacterial, and antacid effects in the digestive tract, and it is commonly used in antidiarrheal over-the-counter medications. When it combines with sulfur in human saliva and in the gastrointestinal tract, it creates a black-colored substance called bismuth sulfide. This is what creates this deceptively frightening black tongue or even darkened stool. The discoloration can linger for a few days, but it's fortunately harmless.

Strange Sleep Behaviors. The FDA, in March 2007, requested that all sedative-hypnotic drug products (that is, sleeping pills) include information about the possible risk of sleep behaviors, including driving while sleeping. Worldwide, there have been reports of adverse reactions to prescription medications used for the short-term treatment of insomnia. These reactions include a woman who did not know why she had gained more than 44 pounds until she found out that she was binge eating from the fridge during her sleep. Another patient woke up holding a paintbrush, only to discover that she'd painted the front door in her sleep. There were also reports given that suggest patients may have driven, made phone calls, or had sexual intercourse—all while sleeping—and with no recollection of having participated in these acts.