6 Strange Drug Side Effects

Side effects may vary, and occasionally take an odd turn.

Everyone knows the common side effects listed on the label of virtually every prescription drug: nausea, constipation, drowsiness, dry mouth, or allergic reactions.

But sometimes, bizarre side effects can present in certain patients.

Here are some of the more peculiar prescription drug side effects that pharmacists may want to mention to patients:

Urine Color Changes

Many drugs can cause changes in urine color, but certain hues are more alarming than others.

Pharmacists are already aware that phenazopyridine (Pyridium), a common OTC analgesic for urinary tract infections, can turn urine orange or even red. But did you know that other drugs can turn urine blue?

Dyrenium, a CYP1A2 substrate used to treat fluid retention and high blood pressure, sometimes turns urine blue. Other medications with this peculiar side effect include amitriptyline (Elavil), indomethacin (Indocin), and propofol (Diprivan).

Then there are the drugs that can turn urine dark brown or even black, including antimalarial drugs chloroquine and primaquine, and the antibiotic metronidazole (Flagyl).

Although they are interesting, these abnormal urine colors could also signal that something is wrong with the body, such as dehydration or internal bleeding.

Painful, Unwanted Erections

Certain drugs sometimes cause priapism, a painful erection that lasts more than 4 hours. But this unusual side effect isn’t limited to erectile dysfunction drugs, as it has been reported with the antidepressant trazodone (Oleptro).

In one case, a male patient sued a pharmacy on the basis that he was not properly counseled about priapism when he filled his trazodone prescription. He woke up with a persistent erection and sought medical attention 30 hours later.

The patient had emergency surgery and was left permanently impotent. The pharmacy was found to be 51% negligent, and the plaintiff was awarded $357,000 in damages.

Hair Growth

Not every unexpected side effect is scary, as some patients welcome effects such as hair growth.

For instance, finasteride (Proscar) was first introduced to treat noncancerous enlargement of the prostate gland, but now, it is also used to treat female hair loss in combination with an oral contraceptive due to a known birth defect potential.

Similarly, minoxidil was originally marketed as an oral high blood pressure medication, but was later found to grow hair in patients. Now, it is a popular OTC remedy for baldness.

Vanishing Fingerprints

On rare occasions, patients taking the cancer drug capecitabine (Xeloda) have lost their fingerprints as a sub-side effect of hand-foot syndrome.

In one case, a 62-year-old male patient with metastatic nasopharyngeal carcinoma was detained in US customs in December 2008 when immigration officers at the airport were unable to detect his fingerprints.

He was later advised to travel with a letter from his oncologist confirming that his condition and associated treatment were the reasons he lacked fingerprints.

Gambling Addiction

One drug’s effect on decision-making and impulse control can cause a patient to develop a gambling addiction.

Pramipexole (Mirapex), a treatment for Parkinson’s disease and restless legs syndrome (RLS), has been the subject of several successful class-action lawsuits against drug manufacturers Boehringer Ingelheim and Pfizer.

In one instance, a retired police officer in Minneapolis, Minnesota, claimed that pramipexole caused him to develop a gambling addiction that lost him $260,000. The jury awarded him all of his gambling losses, in addition to punitive damages.

Sleep-Living

Prescription insomnia treatment zolpidem (Ambien) is effective for patients who need a good night’s sleep, but some users have reported bizarre behaviors while taking the drug.

Patients taking Ambien have reportedly gotten up in the middle of the night and participated in activities such as sleep eating, sleep sex, and even sleep driving while in a dream-like state. Many have no memory of these events the next morning.