A “lithium high” refers to lithium toxicity or overdose, a serious medical condition. Lithium is a prescription medication primarily used to manage certain mental health conditions. When the amount of lithium in the body becomes too high, it can lead to a range of adverse effects, from mild discomfort to life-threatening complications. Understanding the signs of this toxicity is important for individuals taking the medication and their caregivers.
Lithium as a Medication
Lithium is a mood stabilizer, primarily prescribed for the treatment of bipolar disorder. It helps to manage acute manic and mixed episodes and is also used for long-term maintenance treatment to prevent recurrence of mood swings. While the exact mechanism of action is not fully understood, it is believed to make the brain less responsive to stimuli that trigger manic episodes and to reduce the responsiveness to certain neurotransmitters.
This medication requires careful management due to its narrow therapeutic index, meaning there is a small difference between a safe and effective dose and a toxic one. Healthcare providers monitor blood levels regularly to ensure the concentration remains within the therapeutic range, typically between 0.6 and 1.2 milliequivalents per liter (mEq/L).
Recognizing Lithium Toxicity
Symptoms of lithium toxicity can vary in severity and may not always directly correlate with the measured blood lithium level, as lithium acts inside cells while blood tests measure extracellular levels. Mild toxicity, typically occurring with serum lithium concentrations between 1.5 and 2.5 mEq/L, can present with gastrointestinal issues such as nausea, vomiting, cramping, and diarrhea. Neurological symptoms at this stage may include lethargy, fatigue, and a fine tremor.
As lithium levels increase to moderate toxicity (generally 2.5 to 3.5 mEq/L), more pronounced neurological symptoms often appear. These can include confusion, agitation, delirium, and a coarse tremor. Other signs may involve uncoordinated movements (ataxia), muscle twitching (myoclonus), slurred speech (dysarthria), and overactive reflexes (hyperreflexia).
Severe lithium toxicity, occurring at concentrations above 3.5 mEq/L, represents a medical emergency. At this stage, symptoms can escalate to coma, seizures, and hyperthermia. Cardiovascular issues such as hypotension and abnormal heart rhythms have also been reported in severe cases. Persistent neurological symptoms can occur even after the acute phase of toxicity.
Factors Leading to Toxicity
Lithium levels can become toxic due to several factors that affect how the body processes and eliminates the medication. Accidental overdose, such as taking an extra pill, can quickly elevate lithium concentrations. Dehydration is a significant risk factor, as it can reduce the kidneys’ ability to excrete lithium, leading to increased levels in the blood. Conditions causing fluid loss, such as vomiting, diarrhea, or fever, can also contribute to dehydration.
Changes in kidney function, often associated with age or underlying medical conditions, can impair lithium clearance, causing levels to rise. Drug interactions are another common cause of toxicity. Certain medications, including nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen, diuretics (“water pills”), and ACE inhibitors (used for high blood pressure and heart failure), can increase lithium levels by affecting renal excretion. Additionally, dietary changes, particularly a low-sodium intake, can influence lithium reabsorption in the kidneys and lead to elevated concentrations.
Responding to Lithium Toxicity
If lithium toxicity is suspected, immediate medical attention is necessary. Contacting emergency services or a poison control center can provide guidance on the next steps. Prompt action is important, as untreated severe toxicity can lead to brain damage, coma, or even death.
Medical interventions for lithium toxicity focus on removing excess lithium and managing symptoms. This may involve stopping lithium administration, administering intravenous fluids to promote lithium excretion, and, in severe cases, procedures like gastric lavage (stomach pumping). Whole-bowel irrigation can be used to flush lithium from the gastrointestinal system. For very high levels or severe neurological symptoms, kidney dialysis (hemodialysis) may be performed.
Preventive measures are important for individuals on lithium therapy. Consistent dosing is important. Maintaining adequate hydration by drinking water regularly is also important. Regular blood tests to monitor lithium levels, kidney function, and thyroid function are recommended. It is also important to inform all healthcare providers about lithium use and any other medications or supplements being taken, as drug interactions can impact lithium levels.