Crazy side effects from medicines you can somehow still buy

Almost everyone has taken some kind of medication, whether it's prescription or over-the-counter. Hopefully, you've read the directions and the potential side effects before taking it, and it's entirely possible you decided those crazy side effects would be worse than whatever you were trying to fix in the first place.

According to the FDA, some of the most common — and absolutely a-OK — side effects are things like anxiety, drooling, high blood pressure, bad dreams, headaches, skin reactions, and … performance problems. Sounds like a good time, right?

That's bad enough, but you already know about all those things. They're not good, but they're widely accepted as possible side effects. What about the other crazy side effects, so weird and so insane they're usually only linked to a single medication? Does your prescription come with a chance of turning into a vampire, suffering a psychotic break, or the potential for some murder? It's possible.

Vegas, baby ... Vegas

Restless leg syndrome is an actual medical condition. (Not like halitosis, which was just made up by Listerine to sell some product. Brilliant, right?) RLS is characterized by a feeling that something's crawling inside your legs and an inability to keep still, and the National Institute of Neurological Disorders and Stroke says it leads to exhaustion because there's no sleep for the restless. Sufferers are usually prescribed drugs called dopamine agonists, and that, says Science Blogs, is what leads to the bizarre side effect: a gambling addiction.

Requip is the trade name of one of the most popular drugs for RLS, and the Mayo Clinic linked the drug to a handful of patients who developed a major problem with compulsive gambling — so bad that a few lost more than $100,000 because of it.

They're pretty sure they know why it happens, too, stressing that people with prior gambling histories are most likely to go back and hit the slots. Requip — and other RLS drugs — are cousins to the drugs used to treat things like Parkinson's, and they're effective because they boost dopamine levels in the brain. That's happy-juice, and since high levels of dopamine have been linked to interfering with how we perceive pleasure, it might also be pushing some RLS sufferers into the casino and maybe the poor house.

We have no record of your identity

First off, cancer is the literal worst. Life with cancer is stressful and bad enough when treatment is going well, and unfortunately, some capecitabine-based drugs (like Xeloda) that treat various types of cancer come with what's called hand-foot syndrome. According to a paper in The Oncologist, the condition is characterized by things like tingling, blistering, and peeling skin on the palms and feet. There can be swelling, pain, and even desquamation, which is a term that means something as nasty as it sounds: the shedding of skin.

Bad, right? No one needs to deal with that, especially someone who's going through cancer treatments. It gets worse, though, because in some cases, a person sheds so much skin that it erases their fingerprints.

Great if you're going to rob a bank, less great if you need your fingerprints to do things like get through immigration to visit family or process documents to make sure that family's taken care of if the worst outcome becomes the ultimate outcome. That's exactly what's happened to some patients, including a 53-year-old man with stage IV cancer who couldn't get documents processed because he had no more fingerprints. CNN says another cancer patient was detained at U.S. immigration for hours because he had no fingerprints, and that's equal parts crazy and heartbreaking.

Snap, crackle, and pop

Osteoporosis is pretty common, and Harvard Health describes it like this: Bones are always breaking down and rebuilding, and when the first part starts happening faster than the second, bones become weak and more prone to breaking. Since the 1990s, drugs called bisphosphonates (like Fosamax, Reclast, Actonel, and Boniva) have been prescribed to slow bone decomposition and ultimately make them stronger.

Only, there's a problem. Any person taking these drugs for longer than five years has about an 11 percent chance of experiencing the problem first-hand. Studies suggest that bisphosphonates are only effective for a few years, and when people continue to use them, they're at risk of spontaneous fractures, according to ABC News. They interviewed NYU Langone Medical Center professor Dr. Kenneth Egol, and he says the bone in question is usually the femur, and he's had patients suffer traumatic, car accident-level fractures of the femur when doing something no more strenuous than walking down stairs.

Merck eventually added fractured femurs to the list of possible side effects of Fosamax, a drug which — just to recap — is prescribed to help prevent bone fractures.

Honest, it was a sleep-killing

Having trouble sleeping? You should know that in 2007, the New York Times reported 13 sleeping pills (including Ambien and Lunesta) were getting new FDA warnings saying people were at risk of not just sleep-walking, but sleep-driving and sleep-eating. Sleep-driving is dangerous for obvious reasons, and sleep-eating is dangerous, too. University of Minnesota researchers said they'd seen about 30 people who had developed sleep-eating disorders after taking Ambien. Others have reported ordering things online or making phone calls, and there are even cases of perfectly normal individuals popping a few sleeping tablets then waking up to find they'd gone on a nighttime murder spree.

No joke. According to a paper from the Primary Care Companion for CNS Disorders, one man — Mr. A — was suffering from depression and the pretty normal stress of being a new parent when he took doctor-prescribed sleep aids, fell asleep, and woke up to find he'd stabbed his wife 20 times. Ms. B was taking doctor-prescribed sleep aids, too, and had taken an extra one when she killed her husband with a metal pipe. She stayed in the house for another day before friends called 911, and responders found her on the verge of killing herself. MedPage Today adds a later case, a 2013 incident where Andrew McClay used a hammer to beat a housemate to death after taking zolpidem and whiskey. That goes way beyond bad dreams.

Mental illness in pill form

In 2016, Britain's House of Commons Defence Committee ruled the anti-malarial drug Lariam was only to be used as a last resort, mostly because of the risk of serious side effects fully acknowledged by the drug's manufacturer. In spite of warnings, Lariam was the go-to anti-malarial for the British military since 1993, and it's also been given to deployed U.S. soldiers. The Conversation says it was still regularly used after a 2013 warning from the FDA said it was known to "induce psychiatric symptoms such as anxiety disorders, paranoia, depression, hallucinations and psychosis." By 2015, around 1,000 servicemen and women had sought psychiatric treatment after being given Lariam.

Tim Notee was one of the lucky ones: He got help, and the help worked. He told The Guardian he was given Lariam before going to Ghana, and within days he was convinced he was the second son of God. Walls moved, colors changed, and he stopped taking allergy medications and wearing his contacts because he was waiting for a miracle to happen. He ended up in the hospital, became focused on meeting Bruce Springsteen, and believed his blood was the true cure for malaria. He got help, but others have been less fortunate: Ireland's RTE linked Lariam to multiple suicides (via The Journal), and one doctor described it as a "horror movie in a pill."

The vampire drug

Levofloxacin is an anti-bacterial, and according to the Mayo Clinic, it's also used to treat people after anthrax exposure. There are a ton of side effects, and most are pretty normal. But this drug also comes with the potential to cause the least awesome part of being a vampire, and that's an extreme sensitivity to sunlight.

You won't be craving blood and you definitely won't be immortal, but there's a chance you might start to burn when you step into the sunlight. It's officially defined by the FDA as severe photosensitivity and phototoxicity, and it's a common enough concern they also recommend that anyone taking it avoids prolonged exposure to sunlight. Anyone who's suffering from this crazy side effect is going to know it, as it's got the potential to cause sunburns, blistering, and some other nastiness. Exudation is a polite way of saying fluids are going to start leaking out of your skin, and if that's not bad enough, the areas most likely to start burning and leaking with even the briefest exposure to the sun are the hands and face, but hey, it's better than anthrax.

Quitting is the worst

The FDA's official line on stop-smoking medications like Chantix is a little vague, and in 2016 it removed a warning that said using the product might have some serious side effects impacting mental health. While the FDA says there's still potential there, it's not as bad as previously thought. Essentially, the "super-serious" part of the warning was dropped.

There's a huge "but" here, though. Medical Daily says over the course of five years, it was linked with 544 suicides and 1,869 more attempted suicides. The FDA and Pfizer maintain there is not a causal link, but the FAA and the DoD still banned pilots and air traffic controllers from using it.

Vice took a closer look at the side effects Chantix users reported, and at the top of the list were things like suicidal thoughts, crazy-intense nightmares, changes in behavior, and thoughts of killing others. In 2007, musician Carter Albrecht started taking Chantix, and after attacking his girlfriend, he headed over to a neighbor's and was ultimately shot and killed. His family blamed Chantix for his bizarre behavior, and more reports started to surface. It's been linked to causing depression, paranoia, and nightmares leading to exhaustion, and Vice spoke to several people who said they considered suicide without really understanding what they were thinking about. A number of studies have been done, but they're largely inconclusive. That's actually even more terrifying.

A modern thalidomide

First, a quick recap of one of the most damaging drugs ever to hit the market. In the 1950s and '60s, thalidomide was marketed as a sleep aid. Northwestern says one in seven Americans took it, and in 1960, there was as much thalidomide being sold as there was aspirin. Gradually, it was discovered that it relieved morning sickness. But it wasn't long before heartbroken parents found out the hard way that the drug interfered with fetal development and caused babies to be born with shortened or non-existent limbs. It's still used today, but only for leprosy and certain types of cancer. Certainly, we've learned our lesson here, right?

Not quite. In 1988, the FDA's Dermatologic Drugs Advisory Committee filed a motion to remove Accutane from the market after it was linked to as many as 1,300 babies born with birth defects like cleft palates, undersized heads, and brain swelling. The drug, which is used to treat severe acne, is well known to cause birth defects and stillbirths, but according to the Embryo Project Encyclopedia of Arizona State University, the FDA decided not to restrict the drug at all, since it was typically prescribed just for a short-term treatment. Instead, women taking the drug must essentially promise to not become pregnant while they're on it, and it's been given to around 12 million people globally.

Your own 'child of the corn'

In 2018, a family from Allen, Texas, gave their 6-year-old a dose of Tamiflu to help her get over a bout of the flu. Unfortunately for her, she was one of the 1 percent of children who experience some heavy side effects that include hallucinations and a sudden psychotic break. The little girl from Texas ran away from school and tried to jump out her second-story bedroom window before her parents restrained her, and LiveScience says this is a rare — but very real — side effect doctors have known about for a long time.

According to NBC News, the warning information on Tamiflu was updated in 2006 after around 100 cases of children becoming delirious and hallucinating were linked to the drug. Weirdly, most of those incidents came from Japan, where Tamiflu already came with a warning label stressing there was a potential for a child patient to suffer a psychotic break while on the medication. U.S. labels only warned about the potential for "seizure and confusion," and that's already pretty scary — especially considering Tamiflu is only meant to shorten the duration of the flu by a day or two, and it only really works if it's prescribed before someone's in the grip of a full-blown flu.

Show off those pearly ... whites?

There's a good chance you've heard of tetracycline. It's an antibiotic used for everything from skin infections and acne to pneumonia and plague (via MedlinePlus). A ton of people have taken it, and before the 1980s, it was deemed perfectly safe and side effect-free for pregnant women, too. As you might guess, that's not entirely true.

According to the Academy of General Dentistry, tetracycline not only passes from a mother to her unborn child, but it has the crazy side effect of staining the child's teeth. Stains are permanent, can be brown, gray, or black, and sometimes appear as a series of stripes. Children who are prescribed the drug develop the staining, too, and it gets even weirder. Staining patterns on some teeth can be read like weather patterns might be read in the rings of a tree trunk. Dentists can even tell if a child with tetracycline-stained teeth suffered from an illness or high fever.

The Mayo Clinic says staining can also develop in the permanent teeth of adults exposed to tetracycline as children, and it's so deeply embedded in teeth and bones that no amount of bleaching is going to be getting that out.

May cause tiredness, weight gain, and complete memory loss

If you're in need of a bit of help getting your cholesterol down, a doctor might prescribe a statin like Lipitor. There are lots of side effects listed on the FDA's official report on Lipitor, but according to Scientific American, there's a really big one that's not on there yet: dementia. The magazine says there have been hundreds of complaints registered with the FDA claiming some people who start taking Lipitor experience complete and terrifying amnesia that might be misdiagnosed as dementia.

One of those people was a former NASA astronaut named Duane Graveline. He started taking Lipitor, then ended up in the hospital after he lost any sense of where he was (in front of his home) or who the strange woman talking to him was (his wife).

A study from the University of Pittsburgh found even patients who didn't experience severe memory loss like Graveline did also seem to suffer other memory problems and difficulties in learning new tasks. In all fairness, some studies showed there was no apparent connection, so this one is still filed under the "Maybe … but scary either way" category.

It makes sense, too. Cholesterol gets a bad reputation for clogging arteries, but it also insulates and supports neurons in the brain — particularly those that are crucial for memory and learning. That's not a smoking gun, but it's pretty close.

A vaginal yeast infection ... in the mouth

There's a good chance you've taken amoxicillin. It's an antibiotic used for common illnesses like pneumonia and UTIs, and it's also what a dentist might prescribe after surgery or getting a tooth pulled. It also has a very, very squicky side effect called thrush.

The problem with amoxicillin — and other antibiotics — is that they can kill the good bacteria that keeps everything in your body running smoothly, along with killing the bad. According to the NHS, killing off some of that bacteria opens the door for a fungal infection to set up shop in your squishy bits, and by that, they mean the vagina and mouth. Vaginal yeast infections and oral thrush are caused by the same fungus (according to the Mayo Clinic), and that means they have the same symptoms: white lesions, redness, possible bleeding, and the growth of fungus that has a definite cottage cheese texture.

Canadian researchers also suggest (via Medical Daily) that amoxicillin is such a common and over-prescribed drug that cases of this particular side effect are under-reported. Eww.

Killing your skin tissues

Lamictal is prescribed for epilepsy, and it has some nasty side effects, according to the all-caps notice on the FDA's official fact sheet. It's been known to cause Stevens-Johnson syndrome in about 8 of every 1,000 patients. It's a serious rash that could be life-threatening, but that's only part of the story.

The NHS says it starts with flu-like symptoms including the development of skin rashes. Those rashes blister, the skin dies, and it starts falling off. It happens to the skin all over the body, but it also targets the mucous membranes: genitals, eyeballs, and the inside lining of the digestive tract, from mouth to South.

Let that sink in for a minute. Some cases are so severe they require intensive care treatment with help from burn units. The skin doesn't heal right, leading to open sores, inside and out and on your eyeballs. Survive, and you're looking at complications like skin infections, sepsis, the buildup of scar tissue (particularly on those mucous membranes), and even blindness. There has to be a better way, right?