For millions of Americans, taking a prescription drug is part of their every day routine. And while the majority of drugs cause minimal side effects, there are some medications that can lead to some very serious and bizarre behaviors and even life-threatening disorders.

Here’s a look at several popular classes of medications people should always do their homework on:

The Big 3 Erectile Dysfunction Medications:

“Some might argue this is purely a ifestyle drug,” said Michael Inzerillo, corporate director of pharmacy at Continuum Health Partners in New York City. “However anywhere from 16 to 46 percent of patients might experience headaches.”

Without naming a specific ED product, Inzerillo said vision problems were also experienced by some patients.

“These particular medications might cause color changes in vision, blurred vision and they also might cause increased sensitivity to light,” he said.

There is also a more serious vision problem that may surface called non-arteritic anterior ischemic optic neuropathy (NAION), which causes a person to experience vision loss due a blockage affecting the optic nerve. In some cases, NAION can lead to permanent damage.

Recent studies have found a link between the main three ED medications and this condition. As a result, the Food and Drug Administration has requested that manufacturers of these products include a warning about the increased risk of NAION.

Click here for more information on these products from the FDA.

Antipsychotic Medications:

The first antipsychotic medications were introduced in the 1950s, according to the National Institutes of Mental Health. But these early days were riddled with obstacles. At the time, many of the medications had very unpleasant side effects including tardiv dyskinesia. This is a neurological syndrome caused by the long-term use of certain antipsychotic drugs, the National Institutes of Health said on its Web site.

Symptoms include:

— Grimacing;

— Tongue protrusion;

— Lip smacking;

— Puckering and pursing;

— Rapid eye blinking.

— Rapid movements of the arms, legs and trunk may also occur.

“These products are very powerful but they do bear some burden of adverse effects,” Inzerillo told FOXNews.com.

It took four decades, but finally in the 1990s several new drugs were developed called “atypical antipsychotics.” While these drugs greatly reduced serious side effects, some of the drugs may cause weight gain or they may cause glucose metabolism orders, according to Inzerillo.

Click here for more information on atypical antipsychotics.


“If someone has epilepsy or a seizure disorder, drug therapy is critically important in controlling seizures,” Inzerillo said. “However, you have to make an informed decision to understand the risks of therapy.”

One particular serious and very rare side effect Inzerillo mentioned was a condition called Stevens-Johnson syndrome.

It’s a disorder of the skin and mucous membranes and often begins with flu-like symptoms followed by inflammation of mucous membranes and a painful red or purplish rash that spreads and blisters, according to the Mayo Clinic. It eventually causes the top layer of your skin to die and shed.

While the exact cause of Stevens-Johnson syndrome can’t always be pinpointed – medications are most often the cause, the Mayo Clinic said on its Web site.

Drugs commonly associated with Stevens-Johnson syndrome include:

— Nonsteroidal anti-inflammatory drugs (NSAIDs)

— Sulfonamides and penicillins


Antihypertensive Medication:

High blood pressure medications are among the most commonly prescribed drugs in the United States. With that said, they also come with a slew of side effects from constipation to headaches.

And that’s not all. Check out these other adverse effects listed by Johns Hopkins University:

— Dehydration;

— Dizziness, light-headedness, or fainting;

— Drowsiness;

— Dry mouth;

— Frequent urination;

— Increased sensitivity to cold;

— Increased sensitivity to sunlight;

— Potassium loss;

— Tender, swollen, or bleeding gums;

— Upset stomach

Antidepressants: Suicidal Thinking

Antidepressants are the most commonly prescribed drugs in the United States, according to the Centers for Disease Control and Prevention. In fact, they beat out high blood pressure medications, high cholesterol and asthma drugs, a CDC study found. But these drugs don’t come without some very serious side effects.

In 2004, the Federal Food and Drug Administration issued a public warning and asked all manufacturers of antidepressants to update the existing ‘black box’ warnings on its products. The warning included increased risks of suicidal thinking and behavior in young adults ages 18 to 24. In 2006, the FDA recommended that the warning get extended to include adults up to the age of 25.

Click here for a list of antidepressant drugs with medication guides.

Prescription Sleep Aids: Bizarre Behavior

This is a true story: A friend of mine was working the overnight shift at a local news station and was having a hard time sleeping. So, he went to his doctor and asked for a prescription sleep aid. Eventually he started to get a good night’s rest – but what happened during those sleeping hours left him more than a little baffled. He recalled one morning when he woke up with a dozen Popsicle sticks covering his chest. At first he blamed his daughters, but after a little investigating he realized he had eaten an entire box of Fudgsicles in the middle of the night. Needless to say, he called his doctor after that incident.

“Certain prescription sleep aids may cause you to sleep walk and in so doing may eat the entire contents of your refrigerator,” Inzerillo said. “There have also been situations where people get in their car and drive. “Now, assuming you make it back home okay, you could have no memory of the event.”

Moral of the story – always talk to your doctor about any bizarre side effects you experience.

“Triple lock your doors and hide the car keys,” Inzerillo said on a lighter note.

The Bottom Line: Use Resources and Ask Questions

“Review adverse effects – but also review if the particular product carries a ‘black box’ warning, which is the strongest warning the FDA places on a medication,” Inzerillo said.

He also suggested getting a drug data summary fact sheet from the pharmacy and checking out drug information online. Inzerillo said Googling the drug and prescribing information works about 90 percent of the time.