Health Letter, July 2019
By Michael Carome, M.D.
Some patients find it difficult or impossible to swallow large tablets or capsules. This problem is particularly common in older patients with neurological disorders that impair swallowing, such as dementia and Parkinson’s disease; xerostomia (decreased saliva production causing dry mouth); and diseases of the throat and esophagus. Young children also often cannot swallow pills or capsules.
To cope with this problem, patients, caregivers and health care providers frequently crush tablets or open capsules and sprinkle the resulting powder, fragments or granules into food or liquids. Some patients also may resort to chewing on the pills or capsules before swallowing. However, an important 2014 review published in Prescrire International warned that many medicines available in tablet or capsule form are not supposed to be crushed, opened or chewed before swallowing — and that doing so may have serious, sometimes deadly, consequences.
Different drug designs
Oral medications available in tablet or capsule form contain one or more active ingredients — the actual drug intended to treat a particular disease or condition — and several inactive ingredients. Inactive ingredients include coating materials, flavorings, dyes and binders that hold tablets or granules from capsules together. Drug companies use complex manufacturing techniques to combine these ingredients into final products that are designed to release their active ingredients at a specific rate and in a specific location within the digestive tract, such as the stomach or the small intestine.
For example, some uncoated, immediate-release tablets are designed to disintegrate quickly in the stomach, whereupon the active ingredients are rapidly absorbed into the bloodstream. For these drugs to work, the active ingredients must be able to withstand exposure to the strong acid found in the stomach before they are absorbed.
For other drugs containing active ingredients that would otherwise be broken down by stomach acid, manufacturers have designed tablets and capsules with acid-resistant coatings (often called enteric coatings). Only when these tablets or capsules move from the stomach to the small intestine will the coating dissolve, allowing release of the active ingredients.
In addition, many drugs in tablet or capsule form are designed to release their active ingredients even more slowly, over a period of 12 to 24 hours as the tablets or granules from the capsule pass through the small intestine. This sustained-release (also called controlled-release, long-acting and extended-release) design provides the convenience of once- or twice-daily dosing and minimizes the variation in the amount of drug in the blood over the course of a day. This design can improve patient compliance and drug effectiveness while decreasing the risk of adverse effects.
Crushing a tablet, opening a capsule or chewing either of these can circumvent many of the protective design features intended to control when and where a drug is released in the digestive tract. Depending on the drug, this can result in overdosing, underdosing or direct toxic injury to the lining of the mouth, stomach or intestines. The Prescrire International review highlighted examples of each of these potentially dangerous circumstances for several commonly used drugs.
For some drugs, crushing, chewing or opening a tablet or capsule before swallowing can cause the rapid absorption of a large amount of the drug, potentially resulting in an overdose. This can be particularly dangerous with drugs for which there is only a small difference between a drug level that is effective and one that is toxic — the so-called “narrow therapeutic range” or margin of safety. Such drugs include digoxin (LANOXIN) and anticoagulants (blood thinners).
Digoxin is approved by the Food and Drug Administration (FDA) to treat heart failure and to slow the heart rate in patients who develop atrial fibrillation, a common abnormal heart rhythm characterized by an irregular and often rapid heart rate. According to the authors of the Prescrire International review, crushing digoxin tablets before swallowing may increase the risk of other dangerous abnormal heart rhythms. These include heart rhythms that are too slow or too fast and may progress to cardiac arrest and death.
Likewise, the authors noted that opening capsules containing the oral anticoagulant dabigatran
(PRADAXA) will increase the amount of drug that is absorbed, exposing the patient to a greater risk of serious bleeding. Both the FDA-approved drug label and the accompanying Medication Guide for patients advise health care providers and patients that dabigatran capsules must be swallowed whole and warn against breaking, chewing or emptying the capsules before taking the drug.
Sustained-release drugs also should not be crushed or chewed before swallowing because doing so will cause the dangerously rapid absorption of a large dose that was intended to be released slowly over many hours. (See text box, below, for stories of patients who have been seriously harmed or killed after ingesting tablets that were chewed or crushed.)
|Serious Adverse Events Following Chewing or Crushing Sustained-Release Medications
Here are just a few examples published in the medical literature of patients who
Damaging the protective coating
In contrast to the prior examples, for some drugs, crushing tablets, opening capsules or chewing either of these before ingestion can result in patients receiving an insufficient dose of the active ingredient. This occurs commonly with medications that have an enteric coating, designed to protect the active ingredient from being destroyed as the tablet or capsule passes through the stomach. Such drugs include proton pump inhibitors, which suppress stomach acid production and are used to treat gastroesophageal reflux (heartburn) and ulcers — for example, omeprazole (PRILOSEC; ZEGERID) — and sulfasalazine (AZULFIDINE ENTABS), which is used to treat rheumatoid arthritis and certain inflammatory diseases affecting the colon.
The authors of the Prescrire International review referenced a case of a 75-year-old man who had severe heartburn. He was diagnosed with severe gastroesophageal reflux disease. His doctor prescribed the proton pump inhibitor omeprazole twice daily. The omeprazole tablets were crushed before being administered via a tube placed in his stomach. After one month of treatment, the man’s heartburn symptoms persisted. Crushing the tablets likely compromised the integrity of their coating, allowing the stomach acid to inactivate the omeprazole, thus rendering the drug ineffective.
Omeprazole also is available over the counter (OTC). The directions in the “Drug Facts” label on the OTC version instruct consumers to swallow the medicine whole and not to chew or crush the tablets.
Finally, the authors of the Prescrire International review reported that some medications have a coating that is intended to prevent the active ingredients from causing ulcers and tissue injury in the mouth, stomach or intestines. For example, crushing certain iron supplements available in tablet form can cause ulcers in the mouth due to exposure to the iron. Likewise, crushing certain potassium supplements can cause ulcers in the intestines.
What You Can Do
When taking a prescription drug, you should never crush a tablet, open a capsule or chew either without first asking the prescribing health care provider or dispensing pharmacist whether it is safe to do so.
For an OTC medication, carefully read the “Drug Facts” section on the label for any instructions advising whether the tablet or capsule should be swallowed whole without crushing, chewing or opening. Carefully adhere to such instructions.
If you are experiencing difficulty swallowing tablets or capsules and are taking a prescription drug that is unsafe to crush, chew or open, consult the prescribing health care professional about other treatment options. There may be a liquid formulation of the same drug. There also may be a smaller tablet or capsule form of the same drug or another drug that you can swallow or that can be safely crushed or opened before ingesting.
 Boehringer Ingelheim Pharmaceuticals Label: dabigatran (PRADAXA). March 2018. https://www.accessdata.fda.gov/drugsatfda_docs/label/2018/022512s035lbl.pdf. Accessed March 14, 2019.
 Purdue Pharma. Label: oxycodone (OXYCONTIN). September 2018. https://www.accessdata.fda.gov/drugsatfda_docs/label/2018/022272s039lbl.pdf. Accessed November 25, 2014.
 ConsumerMedSafety.org. Cutting, crushing, chewing, opening, or dissolving medicines. March 7, 2014. http://www.consumermedsafety.org/the-basics/when-it-s-not-safe-to-cut-crush-or-chew-otc-medicines. Accessed March 14, 2019.