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Prisoner Health Update: Over-the-Counter Medications

by Eike Blohm, MD

Various medications are available to prisoners for purchase in commissaries and can be taken without instructions from medical staff. Yet taken incorrectly, these medications may have significant adverse effects or result in false positive drug tests, leading to loss of good time and potentially solitary confinement.


Acetaminophen (Tylenol ®) is one of the most frequently used analgesics (pain reliever) in the U.S. It also has antipyretic (fever reducing) effects. Despite decades of use, it is still not entirely understood how it actually works. Likely, it modulates the sensation of pain in the brain rather than working at the site where the pain originates. A person can safely take 1,000 mg three times a day if the doses are spaced six-to-eight hours apart. In normal dosing, acetaminophen does not damage the liver and even people with cirrhosis (liver scarring) can safely take the medication. However, using more than 6,000 mg a day can lead to liver damage.

Non-steroidal Anti-inflammatory Drugs

In addition to treating pain and fever, NSAIDs also fight inflammation. The process of inflammation is integral to the body repairing damaged tissue (e.g., ankle sprain) and fighting infection (e.g., cellulitis). Unlike acetaminophen, NSAIDs actually address the source of the pain, at least in part. NSAIDs are a family of chemically different compounds; aspirin is a salicylic acid derivative, while ibuprofen is based on propionic acid. For that reason, one particular NSAID may work better for one person than another.

Most NSAIDs have a therapeutic ceiling, meaning that taking more does not provide any additional effect (though it increases toxicity). For ibuprofen (Motrin ®), taking more than 400 mg will not provide additional pain relief. For inflammation the maximum effect is seen at 800 mg every six hours.

Adverse effects of NSAIDs are typically seen with long-term use (greater than one week). These drugs reduce blood flow to the kidneys and can thus cause kidney damage. They also reduce the amount of mucous that the stomach makes to protect itself from its own acid, so use of NSAIDs can lead to gastritis and gastric ulcers. Lastly – and ironically – both NSAIDs and acetaminophen can cause a headache with chronic use, which will only go away once the medication is stopped.


Loperamide (Immodium ®) is a medication that treats diarrhea. It is the only opioid sold over-the-counter in the U.S. because it is very poorly absorbed. The drug is recognized by P-glycoprotein pumps which – like a bilge pump on a boat – pump any absorbed loperamide right back into the intestine. However, if taken in excess it can overwhelm the pumps and lead to a positive drug test as well as heart arrhythmias.

Pepto Bismol

This well-known pink liquid is used for stomach upset and diarrhea. Its active ingredient – bismuth subsalicylate – is relatively benign, but can turn stool tar-black. This alone is not dangerous, but the appearance of black stool is often worrisome to patients as well as medical providers, since it is also seen with intestinal bleeding. Blood turns black as it is digested (melena). Thus, unless a medical provider tests the black stool to find it contains no blood, this benign discoloration may lead to invasive, unnecessary medical testing.


The carbonate anion of calcium carbonate absorbs stomach acid, converting it to water and carbon dioxide. The calcium will get absorbed, and in overuse (more than 15 tablets per day) can produce hypercalcemia (high blood calcium levels). This in turn causes abdominal pain – which may lead to more Tums use – and kidney stones. It can even lead to psychosis. In addition, the buffering of acid results in the body’s pH rising and can result in milk-alkali-syndrome.


Vitamin D allows the body to absorb calcium. Taking large amounts of supplemental vitamin D results in hypercalcemia as discussed above.

Vitamin C is a water-soluble vitamin. This means that the body has no good place to store it, and taking more than 100% of the recommended daily amount (RDA) just results in the excess vitamin C being excreted in the urine. Since vitamin C is ascorbic acid, which lowers the pH of urine, it can predispose users to kidney stones. Contrary to popular belief, high doses of vitamin C do NOT help the body fight colds or COVID-19, as long as the person is not vitamin C deficient.

Vitamin B12 is also water soluble. It turns urine into a fluorescent yellow color, which is benign but might alarm some people.

Niacin, part of the vitamin-B complex, can produce a “flush reaction” in susceptible individuals. Even at normal doses it can cause a red rash that feels like a sunburn. This is benign and goes away in a few hours, but it is often confused with an allergy. A myth about niacin is that it helps “flush” drugs from the body to avoid detection in urine drug testing, which is untrue. 

Disclaimer: This column aims to educate prisoners about common health concerns but does not constitute medical advice. It is no substitute for evaluation by a trained medical professional.