Altered mental status (AMS) refers to a noticeable change in a person’s usual brain function, impacting their awareness, thought processes, and behavior. While various medical conditions can lead to this state, many medications and substances, both prescribed and otherwise, are known to induce AMS.
What is Altered Mental Status?
Altered mental status is a broad term for a deviation from a person’s normal state of consciousness or mental clarity. It is a symptom, not a specific diagnosis, indicating changed brain function. Common signs include confusion, disorientation, difficulty concentrating, unusual drowsiness, agitation, or uncharacteristic behaviors. Decreased alertness and impaired judgment are also frequent indicators.
Prescription Medications That Can Cause Altered Mental Status
Prescription medications can affect brain function, leading to altered mental status, often by impacting neurotransmitters or central nervous system processes.
Opioids, such as morphine or oxycodone, are potent pain relievers that can cause confusion, sleepiness, and memory loss by depressing the central nervous system. Sedatives and hypnotics, like benzodiazepines (e.g., diazepam), increase the activity of gamma-aminobutyric acid (GABA), a neurotransmitter that slows brain activity. This can result in sedation, confusion, and impaired short-term memory.
Anticholinergic medications, which include some antihistamines, tricyclic antidepressants, and certain bladder control drugs, can block the action of acetylcholine. Acetylcholine is a neurotransmitter important for learning and memory; its disruption can lead to drowsiness, confusion, and cognitive impairment. Antipsychotics, used to manage severe mental health conditions, can also cause AMS through their effects on various neurotransmitters, potentially resulting in sedation or agitation.
Antidepressants, especially tricyclic antidepressants, can induce mental confusion, drowsiness, and in overdose, lead to more severe symptoms like delirium, hallucinations, or coma. Selective serotonin reuptake inhibitors (SSRIs) can also cause altered mental status, particularly in cases of overdose, leading to serotonin syndrome characterized by agitation and delirium. Anticonvulsants, prescribed for seizure disorders, can sometimes cause confusion, dizziness, and sedation as they stabilize electrical activity in the brain.
Corticosteroids, such as prednisone, are anti-inflammatory drugs that can induce mood and cognitive changes, including confusion, disorientation, and even psychosis, especially at higher doses. Muscle relaxants, used to alleviate muscle spasms, often depress the central nervous system, leading to drowsiness, dizziness, and confusion. Certain cardiovascular medications, like beta-blockers, can also rarely contribute to altered mental status, though the mechanisms are less direct and often involve systemic effects or toxicity.
Over-the-Counter and Illicit Substances
Over-the-counter (OTC) medications and illicit substances can also significantly alter mental status. OTC antihistamines, particularly first-generation types like diphenhydramine, are known to cross the blood-brain barrier and block histamine receptors, leading to drowsiness, confusion, and impaired cognitive function. Many cold and flu medications contain ingredients that can cause sedation or, conversely, agitation and sleeplessness, depending on their stimulant or sedative components. Certain sleep aids, often containing antihistamines, can similarly induce confusion and excessive drowsiness.
Illicit substances pose a considerable risk for altered mental status due to their potent and often unpredictable effects on the brain. Stimulants like cocaine and methamphetamine can cause extreme agitation, paranoia, hallucinations, and confusion by dramatically increasing neurotransmitter activity. Depressants, such as heroin or illicitly obtained benzodiazepines, slow down the central nervous system, leading to severe sedation, impaired judgment, and potentially unconsciousness or coma. Hallucinogens, including LSD, psilocybin (magic mushrooms), and ecstasy, profoundly alter perception, sensation, and mood, often causing vivid hallucinations, distorted reality, and a skewed sense of time. Cannabis can induce altered senses, euphoria, and impaired memory and concentration, with higher doses potentially leading to anxiety, paranoia, or psychosis.
Factors Increasing the Likelihood of Altered Mental Status
The development of drug-induced altered mental status is not solely dependent on the substance itself; several individual factors can increase a person’s susceptibility. Taking multiple medications simultaneously, a practice known as polypharmacy, escalates the risk of drug interactions and cumulative side effects that can lead to AMS. Age is another significant factor, as elderly individuals are often more sensitive to drug effects due to changes in metabolism, reduced kidney and liver function, and a more permeable blood-brain barrier.
Pre-existing medical conditions, such as kidney or liver impairment, can hinder the body’s ability to clear drugs, leading to higher concentrations and increased toxicity. Conditions like dementia or other neurological disorders can also make the brain more vulnerable to drug-induced confusion. The dosage and duration of drug use play a direct role; higher doses or prolonged use generally increase the likelihood and severity of AMS. Furthermore, drug interactions, including those with alcohol, can amplify side effects. Individual sensitivity, influenced by genetic variations or unique physiological responses, means that some people may experience AMS even at typical doses.
When to Seek Medical Attention
If someone exhibits sudden or significant changes in their mental state, such as acute confusion, severe disorientation, unresponsiveness, or unusual behaviors, immediate medical evaluation is necessary. Altered mental status is a serious symptom that requires prompt assessment to identify the underlying cause and prevent further complications.
In such situations, it is important to call emergency services, such as 911, or contact poison control for guidance. Avoid attempting to “wait it out” or administer other substances. When medical professionals arrive, provide all available information about any medications, supplements, or illicit substances the individual may have taken. This information is crucial for guiding diagnosis and treatment.