Lithium is a medication prescribed for bipolar mania and resistant depression. It is a drug with very simple chemical structure but with complex mechanism of action. In addition The medication can easily become toxic and lithium toxicity can be lethal.
What are Causes?
Usually the toxicity is seen in patients with long term therapy. It is usually not toxic if you take a large single dose. Lithium toxicity is commonly caused by long term accumulation of lithium inside the body.
The toxicity is usually precipitated by dehydration, concurrent use of diuretic drugs such as HCT (Hydrochloro thiazide), usage of over the counter pain killers such as NSAIDS (Motrin, Naprosyn, and Advil), rapid increase in the dose and renal impairment.
So patients are usually advised to stop lithium therapy and see their doctor, if they stop eating or drinking due to any reason. In addition it is also important to tell that you are on lithium, whenever you take treatment from a general practitioner.
In addition patients are advised to check their blood lithium levels every six months, once they are stabilized.
What are the Symptoms?
Lithium toxicity is a very serious complication of lithium therapy. If not identified, it can become lethal. So early identification of toxicity is very important, in addition the toxicity features should be separated from lithium side effects.
>Early signs
- * Marked tremor: – Usually it can cause a fine tremor as a side effect. But marked coarse tremor is a toxic effect.
- * Loss of appetite, nausea and vomiting: – When these three symptoms are associated, it is due to toxicity.
- * Diarrhea
- * Lethargy can be nonspecific symptom of lithium toxicity.
>Late signs
- * Restlessness
- * Muscle twitching
- * Abnormal muscle movements: -These are usually dancing like abnormal movements that cannot be controlled by the patient.
- * Muscle incoordination: – Characterized by marked tremors when moving the limbs.
- * Difficulty in speaking
- * Epileptic fits
If you see any of the signs described above then you must admit the patient to a hospital emergency department right away.
How it is Managed?
Once the diagnosis is confirmed, lithium is stopped. Then an urgent serum Lithium blood level is done. After that, intravenous normal saline infusions are started to clear out it from the blood (if the kidneys are normal). If the lithium level is too high, or renal failure is present, dialysis (hemodialysis) is the treatment of choice. In addition supportive therapy is done until the patient recovers from the lithium toxicity.
Additional Information: Disease-related Concerns in Individuals Taking Lithium
Lithium is a potentially lethal medication at toxic doses, and can cause numerous adverse effects at therapeutic levels. There are specific concerns regarding the side effects of lithium in individuals with various medical conditions including heart disease, impaired kidney function, thyroid disease, and dehydration from any cause.
* Cardiovascular disease: Lithium should be used with caution in people who have mild to moderate heart disease. Known cardiac side effects that could have dangerous consequences in people with cardiovascular disease include bradycardia (slow heart rate), cardiac arrhythmia, reversible flattened or inverted T waves on an electrocardiogram or “EKG”, and hypotension (low blood pressure).
* Renal impairment: Lithium should be used with extreme caution in patients with mild to moderate impairment of kidney function. Lithium levels should be monitored frequently in all individuals on this drug. Those people with reduced kidney function should have their dose adjusted based on their estimated creatinine clearance (Clcr) as follows:
- Clcr 10-50 mL/minute: Administer 50% to 75% of the normal lithium dose.
- Clcr <10 mL/minute: Administer 25% to 50% of the normal dose of lithium.
* Thyroid disease: Individuals with thyroid disease should use the drug with caution. Thyroid side effects can occur in both men and women on lithium and may result in one of three thyroid abnormalities: hyperthyroidism, hypothyroidism or euthyroid goiter (enlargement of the thyroid with normal levels of thyroid stimulating hormone [TSH], and the thyroid hormones T4 and T3).
* Dehydration: Prolonged or severe fluid losses can significantly increase the toxicity of lithium. Thus, the drug should be used with caution in patients with medical conditions that cause significant fluid losses such as long periods of sweating, diarrhea, or a lengthy fever. In some situations the dose in these patients may need to be reduced, or even discontinued, temporarily.
As discussed above, there are numerous disease-related concerns regarding its side effects. Individuals starting lithium who have pre-existing medical conditions, or those who develop medical conditions while taking this medication, should work closely with their physician to avoid these potentially dangerous adverse effects.
Conclusion
Lithium is a medication that can easily become toxic. The toxicity can kill you, so early identification of lithium toxicity symptoms and prompt treatment is very important.
