lithium carbonate(redirected from Lithium toxicity)
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Pharmacologic class: Miscellaneous CNS drug
Therapeutic class: Antimanic drug
Pregnancy risk category D
FDA Box Warning
• Lithium toxicity is closely related to lithium blood level and can occur at doses close to therapeutic levels. Before starting therapy, ensure that resources for prompt, accurate blood lithium testing are available.
Unknown. Thought to disrupt sodium exchange and transport in nerves and muscles and control reuptake of neurotransmitters.
Capsules: 150 mg, 300 mg, 600 mg
Syrup (citrate): 300 mg (8 mEq lithium)/5 ml
Tablets: 300 mg
Tablets (extended-release): 300 mg, 450 mg
Tablets (slow-release): 300 mg
Indications and dosages
➣ Manic episodes of bipolar disorder
Adults and children ages 12 and older: 900 to 1,800 mg P.O. daily in divided doses (for example, 300 to 600 mg t.i.d. or 450 to 900 mg b.i.d. of controlled- or slow-release form) to achieve blood level of 1 to 1.5 mEq/L; measure blood level twice weekly until patient stabilizes. Maintenance dosage is 900 to 1,200 mg/day in divided doses (forexample, 300 to 400 mg t.i.d. or 450 to 600 mg b.i.d. of controlled- or slow-release form) to maintain blood level of 0.6 to 1.2 mEq/L. Monitor blood level at least q 2 months.
• Impaired renal function
• Elderly patients
• Acute manic episodes in children
• Corticosteroid-induced psychosis
• Neutropenia secondary to antineoplastic therapy
• Tardive dyskinesia
Use cautiously in:
• hepatic or thyroid disease, severe cardiovascular or renal disease, diabetes mellitus, seizure disorders, systemic infections, brain trauma, organic brain syndrome, urinary retention, severe sodium depletion
• elderly patients
• pregnant or breastfeeding patients
• children (safety not established).
☞ Be aware that dosages are individualized according to lithium blood level and response.
• Give with food or milk to minimize GI upset.
• Make sure patient swallows slow-release tablet whole without chewing or crushing.
• When switching patient from immediate-release to controlled- or slow-release form, give same total daily dosage.
CNS: dizziness, drowsiness, headache, tremor, tics, EEG changes, ataxia, choreoathetotic movements, abnormal tongue movements, extrapyramidal reactions, cogwheel rigidity, blackout spells, psychomotor retardation, slow mental functioning, slurred speech, startled response, restlessness, agitation, confusion, hallucinations, poor memory, worsening of organic brain syndrome, stupor, coma, epileptiform seizures
CV: bradycardia, ECG changes, hypotension, sinus node dysfunction with severe bradycardia and syncope, arrhythmias, peripheral circulatory collapse
EENT: blurred vision, nystagmus, tinnitus
GI: nausea, vomiting, diarrhea, abdominal pain, fecal incontinence, gastritis, flatulence, dyspepsia, anorexia, increased salivation, salivary gland swelling, dry mouth
GU: urinary incontinence, glycosuria, albuminuria, erectile or other sexual dysfunction, polyuria or other signs of nephrogenic diabetes insipidus, oliguria
Metabolic: hypothyroidism or hyperthyroidism, goiter, hyperglycemia, hypercalcemia, hyponatremia, hyperparathyroidism
Musculoskeletal: swollen or painful joints, muscle weakness, muscle fasciculations and twitching, clonic arm or leg movements, hypertonicity, hyperactive deep tendon reflexes, polyarthralgia
Skin: dry thin hair, alopecia, diminished or absent skin sensations, chronic folliculitis, eczema with dry skin, new onset or exacerbation of psoriasis, pruritus (with or without rash), cutaneous ulcers, angioedema
Other: altered, metallic, or salty taste; dental caries; weight gain; excessive thirst; polydipsia; fever; edema of lips, ankles, and wrists
Drug-drug. Acetazolamide, alkalinizing agents (such as sodium bicarbonate), urea, verapamil, xanthines: decreased lithium blood level
Calcium channel blockers, carbamazepine, haloperidol, methyldopa: increased risk of neurotoxicity
Diuretics: increased sodium loss, increased risk of lithium toxicity
Fluoxetine, loop diuretics, metronidazole, nonsteroidal anti-inflammatory drugs: increased risk of lithium toxicity
Iodide salts: synergistic effects, increased risk of hypothyroidism
Neuromuscular blockers: prolonged neuromuscular blockade, severe respiratory depression
Phenothiazines: decreased phenothiazine blood level or increased lithium blood level, greater risk of neurotoxicity
Selective serotonin reuptake inhibitors: increased risk of tremor, confusion, dizziness, agitation, and diarrhea
Sympathomimetics: decreased pressor sensitivity
Tricyclic antidepressants: increased antidepressant effects
Drug-diagnostic tests. Albumin, creatinine, sodium, thyroxine, triiodothyronine: decreased levels
Calcium, glucose,131I uptake, white blood cells (WBCs): increased levels
Drug-food. Caffeine-containing foods and beverages: decreased lithium blood level and efficacy
Drug-herbs. Caffeine-containing herbs (cola nut, guarana, yerba maté): decreased lithium blood level and efficacy
• Obtain baseline ECG and electrolyte levels before and periodically during therapy.
• Assess neurologic and psychiatric status. Institute safety measures as needed to prevent injury.
• Monitor lithium blood level, WBC count, and thyroid and kidney function tests.
• Assess cardiovascular status regularly.
• Monitor fluid intake and output. Watch for edema and weight gain.
• Advise patient to take with food or milk to minimize GI upset.
• Instruct patient to swallow slow-release tablet whole without chewing or crushing.
• Tell patient that beneficial effects may take 1 to 3 weeks to appear.
• Advise patient to limit foods and beverages containing caffeine, because they may interfere with drug action.
• Tell patient to maintain adequate fluid intake.
• Explain that drug may cause adverse CNS effects. Advise patient to avoid activities requiring mental alertness until effects are known.
☞ Emphasize importance of having regular blood tests, to help detect and prevent serious adverse reactions.
• Instruct patient to carry appropriate medical identification at all times.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, foods, and herbs mentioned above.