FDA label a4e9517c-7696-9f50-e053-2995a90a460a

WARNING Lithium toxicity is closely related to serum lithium levels, and can occur at doses close to therapeutic levels. Facilities for prompt and accurate serum lithium determinations should be available before initiating therapy (see DOSAGE AND ADMINISTRATION ).

WARNINGS Lithium may cause fetal harm when administered to a pregnant woman. There have been reports of lithium having adverse effects on nidations in rats, embryo viability in mice, and metabolism in-vitro of rat testis and human spermatozoa have been attributed to lithium, as have teratogenicity in submammalian species and cleft palates in mice. Studies in rats, rabbits and monkeys have shown no evidence of lithium-induced teratology. Data from lithium birth registries suggest an increase in cardiac and other anomalies, especially Ebstein’s anomaly. If the patient becomes pregnant while taking lithium, she should be apprised of the potential risk to the fetus. If possible, lithium should be withdrawn for at least the first trimester unless it is determined that this would seriously endanger the mother. Chronic lithium therapy may be associated with diminution of renal concentrating ability, occasionally presenting as nephrogenic diabetes insipidus, with polyuria and polydipsia. Such patients should be carefully managed to avoid dehydration with resulting lithium retention and toxicity. This condition is usually reversible when lithium is discontinued. Morphologic changes with glomerular and interstitial fibrosis and nephron-atrophy have been reported in patients on chronic lithium therapy. Morphologic changes have also been seen in bipolar patients never exposed to lithium. The relationship between renal functional and morphologic changes and their association with lithium therapy has not been established. When kidney function is assessed, for baseline data prior to starting lithium therapy or thereafter, routine urinalysis and other tests may be used to evaluate tubular function (e.g., urine specific gravity or osmolality following a period of water deprivation, or 24-hour urine volume) and glomerular function (e.g., serum creatinine or creatinine clearance). During lithium therapy, progressive or sudden changes in renal function, even within the normal range, indicate the need for reevaluation of treatment. Lithium toxicity is closely related to serum lithium levels, and can occur at doses close to therapeutic levels (see DOSAGE AND ADMINISTRATION ).

ADVERSE REACTIONS Lithium Toxicity The likelihood of toxicity increases with increasing serum lithium levels. Serum lithium levels greater than 1.5 mEq/mL carry a greater risk than lower levels. However, patients sensitive to lithium may exhibit toxic signs at serum levels below 1.5 mEq/mL. Diarrhea, vomiting, drowsiness, muscular weakness and lack of coordination may be early signs of lithium toxicity, and can occur at lithium levels below 2.0 mEq/mL. At higher levels, giddiness, ataxia, blurred vision, tinnitus and a large output of dilute urine may be seen. Serum lithium levels above 3.0 mEq/mL may produce a complex clinical picture involving multiple organs and organ systems. Serum lithium levels should not be permitted to exceed 2.0 mEq/mL during the acute treatment phase. Fine hand tremor, polyuria and mild thirst may occur during initial therapy for the acute manic phase, and may persist throughout treatment. Transient and mild nausea and general discomfort may also appear during the first few days of lithium administration. These side effects are an inconvenience rather than a disabling condition, and usually subside with continued treatment or a temporary reduction or cessation of dosage. If persistent, a cessation of dosage is indicated. The following adverse reactions have been reported and do not appear to be directly related to serum lithium levels. Neuromuscular: Tremor, muscle hyperirritability (fasciculations, twitching, clonic movements of whole limbs), ataxia, choreo-athetotic movements, hyperactive deep tendon reflexes. Central Nervous System: Blackout spells, epileptiform seizures, slurred speech, dizziness, vertigo, incontinence of urine or feces, somnolence, psychomotor retardation, restlessness, confusion, stupor, coma, acute dystonia, downbeat nystagmus. Cardiovascular: Cardiac arrhythmia, hypotension, peripheral circulatory collapse, sinus node dysfunction with severe bradycardia (which may result in syncope). Neurological: Cases of pseudotumor cerebri (increased intracranial pressure and papilledema) have been reported with lithium use. If undetected, this condition may result in enlargement of the blind spot, constriction of visual fields and eventual blindness due to optic atrophy. Lithium should be discontinued, if clinically possible, if this syndrome occurs. Gastrointestinal: Anorexia, nausea, vomiting, diarrhea. Genitourinary: Albuminuria, oliguria, polyuria, glycosuria. Dermatologic: Drying and thinning of hair, anesthesia of skin, chronic folliculitis, xerosis cutis, alopecia and exacerbation of psoriasis. Autonomic Nervous System: Blurred vision, dry mouth. Thyroid Abnormalities: Euthyroid goiter and/or hypothyroidism (including myxedema) accompanied by lower T 3 and T 4 . Iodine 131 uptake may be elevated. (See PRECAUTIONS ). Paradoxically, rare cases of hyperthyroidism have been reported. EEG Changes: Diffuse slowing, widening of frequency spectrum, potentiation and disorganization of background rhythm. EKG Changes: Reversible flattening, isoelectricity or inversion of T-waves. Miscellaneous: Fatigue, lethargy, transient scotomata, dehydration, weight loss, tendency to sleep. Miscellaneous Reactions Unrelated to Dosage are: Transient electroencephalographic and electrocardiographic changes, leucocytosis, headache, diffuse non-toxic goiter with or without hypothyroidism, transient hyperglycemia, generalized pruritis with or without rash, cutaneous ulcers, albuminuria, worsening of organic brain syndromes, excessive weight gain, edematous swelling of ankles or wrists, and thirst or polyuria, sometimes resembling diabetes insipidus, and metallic taste. A single report has been received of the development of painful discoloration of fingers and toes and coldness of the extremities within one day of the starting of treatment of lithium. The mechanism through which these symptoms (resembling Raynaud’s Syndrome) developed is not known. Recovery followed discontinuance.