Lithium carbonate

Absorption

Lithium absorption is rapid and oral bioavailability is close to 100%.

Toxicity

In rats, the oral LD50 is 525mg/kg and the inhalation LC50 is >2.17mg/L over 4 hours.
There is insufficient data regarding the carcinogenicity, mutagenicity, or fertility impairment of lithium carbonate. However, studies in rats and mice have shown repeated daily dosing of lithium carbonate result in adverse effects on male reproductive organs, spermatogenesis, and testosterone levels.
There is conflicting evidence regarding the incidence of cardiovascular abnormalities in first trimester administration of lithium. Animal studies have shown adverse effects on the fetus and fertility overall. The risk and benefit of lithium use in pregnancy must be weighed and should lithium treatment continue in pregnancy, serum lithium concentrations should be regularly monitored, dosages should be adjusted, and lithium should be decreased or stopped 2 or 3 days before delivery to avoid maternal and/or neonatal toxicity.
Breastfeeding is not recommended with maternal lithium use but if it is continued, the infant should be monitored for thyroid function and symptoms of lithium toxicity such as hypertonia, hypothermia, cyanosis, and ECG changes.

Description

Lithium carbonate is a white hygroscopicpowder. Molecular weight = 73.89; Boiling point = 1310℃(decomposes below BP); Freezing/Meltingpoint = 618-735℃. Hazard Identification (based onNFPA-704 M Rating System): Health 1, Flammability 0,Reactivity 1. Slightly soluble in water.

Background

Lithium has been used to treat manic episodes since the 19th century. Though it is widely used, its mechanism of action is still unknown. Lithium carbonate has a narrow therapeutic range and so careful monitoring is required to avoid adverse effects.

Indications

Lithium carbonate is indicated as a monotherapy for the treatment of acute manic and mixed episodes associated with bipolar 1 disorder in patients ≥7 years of age. It is also indicated as a maintenance treatment for bipolar 1 disorder in patients ≥7 years of age.

Pharmacokinetics

Lithium's mechanism of action is still unknown. Lithium's therapeutic action may be due to a number of effects, ranging from inhibition of enzymes such as glycogen synthase kinase 3, inositol phosphatases, or modulation of glutamate receptors.

Side Effects

Drowsiness, dizziness, tiredness, increased thirst, increased frequency of urination, weight gain, and mildly shaking hands (fine tremor) may occur. These should go away as your body adjusts to the medication. This medication may increase serotonin and rarely cause a very serious condition called serotonin syndrome/toxicity. The risk increases if you are also taking other drugs that increase serotonin, so tell your doctor or pharmacist of all the drugs you take (see Drug Interactions section). Get medical help right away if you develop some of the following symptoms: fast heartbeat, hallucinations, loss of coordination, severe dizziness, severe nausea/vomiting/diarrhea, twitching muscles, unexplained fever, unusual agitation/restlessness.

First aid

If this chemical gets into the eyes, remove anycontact lenses at once and irrigate immediately for at least15 min, occasionally lifting upper and lower lids. Seek medical attention immediately. If this chemical contacts theskin, remove contaminated clothing and wash immediatelywith soap and water. Seek medical attention immediately. Ifthis chemical has been inhaled, remove from exposure,begin rescue breathing (using universal precautions, including resuscitation mask) if breathing has stopped and CPR ifheart action has stopped. Transfer promptly to a medicalfacility. When this chemical has been swallowed, get medical attention. Give large quantities of water and inducevomiting. Do not make an unconscious person vomit.Medical observation is recommended for 24-48 h afterbreathing overexposure, as pulmonary edema may bedelayed. As first aid for pulmonary edema, a doctor orauthorized paramedic may consider administering a corticosteroid spray.

Metabolism

Lithium carbonate is not metabolized before excretion.