Delirium is a serious medical condition characterized by an acute change in mental state, often manifesting as confusion and altered awareness. Medications are a significant and common factor that can contribute to or directly cause this condition. Recognizing the connection between certain drugs and delirium is important for both patients and healthcare providers.
Understanding Delirium
Delirium represents a sudden and fluctuating disturbance in attention, awareness, and cognition. It typically develops over hours or days, distinguishing it from conditions like dementia, which involve a more gradual decline in cognitive function over months or years. The symptoms of delirium can vary throughout the day, often worsening at night.
This condition is considered a medical emergency requiring prompt assessment and intervention. Delirium can present in different ways, including hypoactive forms marked by inactivity and drowsiness, hyperactive forms characterized by restlessness and agitation, or a mixed presentation. It affects a person’s ability to think clearly, focus, and understand their surroundings.
Medications Implicated in Delirium
Many classes of medications can cause or worsen delirium, particularly in vulnerable individuals such as older adults. One prominent group is anticholinergic medications, which block the action of a neurotransmitter called acetylcholine. Common examples include certain antihistamines like diphenhydramine (found in many over-the-counter sleep aids and cold medicines), some antidepressants (e.g., tricyclic antidepressants), and medications for overactive bladder or muscle spasms (e.g., oxybutynin, dicyclomine).
Sedatives and hypnotics, including benzodiazepines (such as lorazepam or midazolam) and “Z-drugs” (like zolpidem), are also frequently implicated. These drugs depress the central nervous system, leading to increased drowsiness and confusion. Long-term use of benzodiazepines can lead to delirium, particularly if stopped abruptly.
Opioid pain medications, such as morphine, fentanyl, oxycodone, and tramadol, are well-known contributors to delirium. Their use can increase the risk of delirium. Corticosteroids, like prednisone, can also induce delirium.
Additionally, some cardiovascular drugs have been linked to delirium. These include certain antiarrhythmics (e.g., disopyramide, digoxin), which can affect the brain, and diuretics, which may cause electrolyte imbalances that impact brain function. Polypharmacy, the concurrent use of multiple medications, significantly increases the likelihood of drug-induced delirium due to potential drug interactions and cumulative side effects.
How Drugs Trigger Delirium
Medications can trigger delirium through several complex pathways within the brain and body. A primary mechanism involves disrupting the balance of neurotransmitters, which are chemical messengers in the brain. For instance, many drugs cause delirium by interfering with acetylcholine, a neurotransmitter important for memory, attention, and learning.
Another pathway involves the neurotransmitter dopamine. Some medications can increase dopamine levels or alter its activity, contributing to symptoms like hallucinations and agitation often seen in hyperactive delirium. Sedative medications, including benzodiazepines, affect gamma-aminobutyric acid (GABA), an inhibitory neurotransmitter. While they initially cause sedation, imbalances or withdrawal can lead to over-excitation and delirium.
Drugs can also cause delirium indirectly by affecting other bodily systems. Kidney or liver impairment, either pre-existing or caused by certain drugs, can reduce the body’s ability to clear medications, leading to their accumulation and increased toxicity in the brain.
What to Do If Delirium Occurs
Recognizing the signs of delirium and acting quickly is important. Key indicators often include a sudden onset of confusion, difficulty concentrating, disorientation to time or place, and problems with memory. A person experiencing delirium might also exhibit fluctuating levels of alertness, unusual drowsiness or agitation, disorganized thinking, or even hallucinations.
If you suspect someone is experiencing delirium, especially if they have recently started a new medication or changed a dose, seek immediate medical attention. Prompt evaluation by a healthcare provider is essential. It is important to inform medical staff about all medications the person is currently taking, including prescriptions, over-the-counter drugs, and herbal supplements.
Do not attempt to stop or change any prescribed medications without consulting a doctor, as this could worsen the condition or lead to withdrawal symptoms. The primary goal of treatment is to identify and address the underlying cause, which often involves adjusting or discontinuing the offending medication if it is safe and appropriate to do so. Supportive care is also provided to manage symptoms and ensure the person’s safety and comfort.