Pronunciation: LITH-ee-uhm
Class: Antipsychotic agent

Trade Names

Eskalith
- Capsules 300 mg lithium carbonate (8.12 mEq lithium)

Lithobid
- Tablets, slow-release 300 mg lithium carbonate (8.12 mEq lithium)

Lithonate
- Capsules 300 mg lithium carbonate (8.12 mEq lithium)

Lithotabs
- Tablets 300 mg lithium carbonate (8.12 mEq lithium)

Apo-Lithium Carbonate (Canada)
Apo-Lithium Carbonate SR (Canada)
Carbolith (Canada)
Duralith (Canada)
PMS-Lithium Carbonate (Canada)
PMS-Lithium Citrate (Canada)

Pharmacology

Specific mechanism unknown; alters sodium transport in nerve and muscle cells and effects shift toward intraneuronal metabolism of catecholamines.

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Pharmacokinetics

Absorption

Readily absorbed from the GI tract. Absorption is not significantly impaired by food. T max is 0.5 to 3 h. Therapeutic serum level is 0.4 to 1 mEq/L. Steady state is reached in 5 to 7 days.

Distribution

Distribution space of lithium approximates that of total body water. Not protein bound. Distribution across the blood-brain barrier is slow; however, the CSF lithium level is about 40% of the plasma concentration.

Elimination

About 95% eliminated by the kidney; primarily excreted in the urine. Renal excretion is proportional to its plasma concentration. The t ½ is about 24 h (10 to 50 h).

Special Populations

Elderly

Decreases rate of excretion; increases incidence of toxic effects. Therefore, lower doses and more frequent monitoring are recommended.

Indications and Usage

Management of bipolar disorder and manic episodes of manic-depressive illness.

Unlabeled Uses

Treatment of neutropenia; unipolar depression; schizoaffective disorder; prophylaxis of cluster headaches; premenstrual tension; tardive dyskinesia; hyperthyroidism; SIADH, postpartum affective psychosis; corticosteroid-induced psychosis.

Contraindications

History of leukemia.

Dosage and Administration

Adults

PO 900 to 1800 mg/day in 2 to 4 divided doses. Give regular capsules 3 or 4 times daily; slow-release tablets 2 or 3 times daily. Max dose, 2,400 mg/day.

Children 12 yr of age and older

15 to 20 mg/kg/day in 2 to 3 divided doses.

General Advice

  • Administer with meals to minimize GI upset.
  • Do not crush, chew, or break extended-release capsules or coated tablets.

Storage/Stability

Store at room temperature. Protect capsules from moisture.

Drug Interactions

Acetazolamide, osmotic diuretics, theophyllines, urinary alkalinizers

Increased renal excretion of lithium.

ACE inhibitors, fluoxetine, loop diuretics, NSAIDs, thiazide diuretics

Increased lithium serum levels.

Carbamazepine, haloperidol, methyldopa

Increased neurotoxic effects despite therapeutic serum levels and normal dosage range.

Iodide salts

Increased risk of hypothyroidism.

Neuromuscular blocking agents, tricyclic antidepressants

Increased pharmacological effects of additive drug.

Phenothiazines

Neurotoxicity, decreased phenothiazine concentrations, or increased lithium concentrations may occur.

Verapamil

Reductions in lithium levels and lithium toxicity have occurred.

Laboratory Test Interactions

None well documented.

Adverse Reactions

Cardiovascular

Arrhythmias; hypotension; bradycardia; peripheral circulatory collapse.

CNS

Tremor; muscle hyperirritability; headache; fatigue; ataxia; dizziness; psychomotor retardation; confusion; dystonia; hallucinations; blackouts; seizures; pseudotumor cerebri; drowsiness; poor memory and intellectual function; muscular weakness; slurred speech.

Dermatologic

Drying or thinning hair; dry skin; pruritus; exacerbation of psoriasis; acne.

EENT

Blurred vision; tinnitus.

GI

Anorexia; nausea; vomiting; diarrhea; sialorrhea; dry mouth; parotitis.

Genitourinary

Urinary urgency; stress incontinence; polyuria; albuminuria; sexual dysfunction; symptoms of nephrogenic diabetes; decreased CrCl.

Hematologic

Leukocytosis; leukemia.

Metabolic

Hypothyroidism; hypercalcemia; hyperparathyroidism; hyponatremia; dehydration; weight gain.

Miscellaneous

Taste distortion; thirst; fever; swollen joints.

Precautions

Warnings

Toxicity is closely related to serum concentrations and may occur at doses close to therapeutic levels. Equipped facilities should be identified prior to initiation of therapy to provide prompt and accurate serum concentration data.


Pregnancy

Category D .

Lactation

Excreted in breast milk.

Children

Safety and efficacy not established in children less than 12 yr.

Renal Function

Chronic use may lead to nephrogenic diabetes insipidus. Patients who have reduced renal function, including elderly, should take lower doses.

Tartrazine Sensitivity

Some products contain tartrazine, which may cause allergic-type reactions in susceptible individuals.

Encephalopathic syndrome

Encephalopathic syndrome has occurred in patients also taking a neuroleptic and may cause irreversible brain damage. Characterized by weakness, lethargy, fever, tremors, confusion, extrapyramidal symptoms, leukocytosis, and elevated serum enzymes, BUN, and fasting blood sugar.

Hypothyroidism

Has occurred with chronic use. Thyroid hormone replacement therapy may be required.

Infections

Reduction in dose or discontinuation may be required if patient has infection with fever, especially if accompanied by protracted sweating, vomiting, or diarrhea.

Sodium/Volume depletion

Because drug decreases renal sodium absorption, patients must maintain adequate salt and fluid intake.

Toxicity

Toxicity can occur even at therapeutic doses. Toxicity risk is greater in patients with renal or CV disease, debilitation, dehydration, or sodium depletion.

Overdosage

Symptoms

ECG changes, slurred speech, seizures, acute renal failure, coma, diarrhea, vomiting, drowsiness, muscle weakness, ataxia.

Patient Information

  • Explain that therapeutic improvement will be noted in 1 to 3 wk.
  • Instruct patient to take medication regularly even if feeling well. Symptoms may return if medication is discontinued.
  • Advise patient not to decrease or increase dietary sodium intake.
  • Tell patient to drink 8 to 10 glasses of water or other caffeine-free liquids daily.
  • Caution patient to avoid excessive caffeine intake, as caffeine may increase urinary excretion of drug.
  • Advise patient that thirst, frequent polyuria, taste distortion, and fine hand tremors are common adverse reactions.
  • Instruct patient to report the following symptoms to health care provider immediately: nausea, vomiting, diarrhea, muscular weakness, ataxia, blurred vision or tinnitus.
  • Advise patient that drug may cause drowsiness and to use caution while driving or performing other tasks requiring mental alertness.
  • Emphasize need for serum lithium level monitoring every 1 or 2 mo or as advised by health care provider.
  • Encourage patient to wear medical identification (eg, card, bracelet) at all times stating medication name and dosage.

Copyright © 2009 Wolters Kluwer Health.

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