Question
How do medications increase the likelihood of dysphagia?
Answer
Medications have a major potential for influencing dysphagia. Almost any medication could have some type of side effect, whether it is impairing consciousness, coordination, sensory function, motor function, or lubrication and peristalsis of the upper aerodigestive tract.
It is not unusual for older adults or individuals with complex medical conditions to be taking multiple medications which can increase the likelihood of drug-induced dysphagia. Certainly, medications affect each person differently. Their effects can be influenced by gender, age, physical body size of the patient, the patient's metabolic status at the time, other medications compounded on one another - polypharmaceutical side effects – as well as each individual person and his or her response. If two individuals take the same medication, even if they are the same gender, the same age, and around the same body size, that medication may affect them differently.
Factors to consider when looking at drug-induced dysphagia are dysphagia due to side effects, dysphagia due to the drug therapy itself, and potential esophageal injury.
Dysphagia due to side effects. The more medications a patient takes, the more polypharmaceutical side effects are possible. One medicine causes a side effect, and then the patient is prescribed another medicine to combat the side effect, but that causes yet another side effect. We get into a “hamster running on the wheel” mode because we are trying to treat one disease or one condition, but the side effects of that treatment cause other conditions.
Xerostomia, or dry mouth, can be caused by allergy medications (antihistamines), medications for depression, angiotensin converting enzyme (ACE) inhibitors, medications for nausea, medications for blood pressure with diuretics in them, cholesterol medications, etc. Medications may also cause decreased taste, or patients may complain of losing their appetites. Medications may increase constipation and then the patient is given another medication to remedy the constipation. Metabolic issues related to how those medications are absorbed can also be a factor. Antipsychotics, which are all too common in patients with dementia, may cause dyskinesias (muscle movement disorders) and when a person has a movement disorder there is an increased likelihood of dysphagia.
Dysphagia due to the drug therapy itself. This is the second factor that can lead to dysphagia. Xerostomia can fall into this category also. Radiation and chemotherapy increase the likelihood of dysphagia, and may also damage the mucosa. If there is damage to the mucosa, that is absolutely going to lead to an increased probability of dysphagia. Individuals who may have had transplants, or are on immunosuppressants or even sometimes antibiotics, may get viral or fungal infections. Thrush in the mouth is a very painful fungal infection. Typically, a mouthwash is given to combat the infection. Unfortunately, the taste of the mouthwash is terrible. Think about patients who have viral or fungal infections, and how those are going to lead to decreased PO intake and the potential for dysphagia.
High-dose corticosteroids, such as prednisone and those types of medications, may lead to muscle wasting. Usually, the muscle wasting does not affect the swallow, but it may. Younger people have to be cautioned when they are on a high dose of corticosteroids, because exercise or physical activity could potentially lead to some injury. Our patients may not be doing high impact exercise or physical activity, but the muscle wasting could have an effect on them as well.
Narcotic pain medications and muscle relaxers can cause decreased muscle control and decreased awareness due to the depression of the central nervous system. Anti-anxiety drugs such as benzodiazepines can also cause a depressed central nervous system. They are used for anxiety, but they do not just lessen the physical anxiety. They depress the nervous system functions, and thus can increase the risk for dysphagia. Anti-psychotics and neuroleptics can cause movement disorders or dyskinesias. Antibiotics can also cause esophogitis, glossitis, or fungal infections.
Esophageal injury. Esophageal injury is the third factor to consider. Patients take medication orally and then perhaps lie down too quickly or do not drink enough with the medication. The primary peristaltic wave has not moved that medication all the way down through the esophagus and into the stomach, so the medications remain in the esophagus for a longer period of time and can cause irritation and potential for esophageal injury. Aspirin, iron, potassium, vitamin C, and non-steroidal anti-inflammatory drugs (NSAIDs) are all common medications that can cause irritation and some injury if they remain in the esophagus.
Again, medications can have a major impact on swallowing. It is important to think about patients that are currently on your caseload and the influence that multiple medications can have on swallowing function and how they can increase the likelihood of drug-induced dysphagia.
Please refer to the SpeechPathology.com course, Dysphagia in Patients with Dementia: What's the SLP to Do? - Part 1, for more in-depth information on the common deficits in stages of cognitive decline and the difference between normal versus disordered swallowing.
