Names and pronunciation
(li′thee-um) Carbolith , Lithane , Lithamax
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Drug reference
(li′thee-um) Carbolith , Lithane , Lithamax
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Func. class.: Psychotropic agent— antimanic
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Chem. class.: Alkali metal ion salt
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Do not confuse: lithium/lanthanum/Ultram
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ACTION: May alter sodium, potas- sium ion transport across cell membrane in nerve, muscle cells; may balance bio- genic amines of norepinephrine, sero- tonin in CNS areas involved in emotional responses
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USES: Bipolar disorders (manic phase), prevention of bipolar manic- depressive psychosis
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Unlabeled uses: Major depression (augmented use)
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CONTRAINDICATIONS: Preg- nancy, breastfeeding, children <12 yr, hepatic disease, brain trauma, organic brain syndrome, schizophrenia, severe cardiac/renal disease, severe dehydration Precautions: Geriatric patients, thyroid disease, seizure disorders, diabetes mel- litus, systemic infection, urinary reten- tion, QT prolongation
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Black Box Warning: Lithium level >1.5 mmol/L DOSAGE AND ROUTES—NTI Bipolar disorder (mania) • Adult: PO 300 mg tid, maintenance 300 mg tid or qid; EXT REL 900 mg q12hr; dose should be individualized to maintain blood levels at 1-1.5 mEq/L or 0.6-1.2 mEq/L (maintenance) • Geriatric: PO 300 mg bid, increase q7days by 300 mg to desired dose • Child: PO 15-20 mg/kg/day in 3-4 di- vided doses; increase as needed; do not exceed adult doses; maintain blood levels at 0.4-0.5 mEq/L Depression (unlabeled use) Adult PO: PO 600 mg tid or 10 mL oral solution tid Renal dose • Adult: PO CCr 10-50 mL/min give 50%- 75% of normal dose, CCr <10 mL/min give 25%-50% of normal dose Black Box Warning: Lithium toxicity: diarrhea, vomiting, tremor, twitching, poor coordination, lassitude; major toxicity, coarse tremors, severe thirst, tinnitus, dilute urine; serum lithium levels week initially, then q2mo (therapeutic level: 0.5-1.5 mEq/L); toxic level >1.5 mcg/L; the drug has a narrow therapeutic index (NTI), measure level before AM dose • Weight daily; check for, report edema in legs, ankles, wrists • Sodium intake: decreased sodium in take with decreased fluid intake may lead to lithium retention; increased sodium, fluids may decrease lithium retention • Skin turgor at least daily • Urine for albuminuria, glycosuria, uric acid during beginning treatment, q2mo thereafter; specific gravity, any level <1.005 may indicate diabetes insipidus and should be reported to prescriber • Thyroid tests (TSH, T4) baseline and q6mo to 1 yr, hypo/hyperthyroidism may occur • Neurologic status: LOC, gait, motor reflexes, hand tremors • ECG in those >50 yr with CV disease; cardiology consult is recommended in those with risk factor; QT prolongation may occur • Pregnancy/breastfeeding: do not use in pregnancy, breastfeeding
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SIDE EFFECTS CNS: Headache, drowsiness, dizziness, tremors, twitching, ataxia, seizure, slurred speech, restlessness, confusion, stupor, memory loss, clonic movements, fatigue CV: Hypotension, ECG changes, dys rhythmias, circulatory collapse, edema, Brugada syndrome, QT prolongation EENT: Tinnitus, blurred vision ENDO: Hyponatremia, goiter, hyperglyce- mia, hypo/hyperthyroidism GI: Dry mouth, anorexia, nausea, vom- iting, diarrhea, incontinence, abdomi- nal pain, metallic taste GU: Polyuria, glycosuria, proteinuria, albu minuria, urinary incontinence, polydipsia HEMA: Leukocytosis INTEG: Drying of hair, alopecia, rash, pru- ritus, hyperkeratosis, acneiform lesions, folliculitis MS: Muscle weakness
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INTERACTIONS Increase: hypothyroid effects—antithy- roid agents, calcium iodide, potassium iodide, iodinated glycerol Increase: effects of neuromuscular blocking agents Increase: renal clearance—sodium bicarbonate, acetaZOLAMIDE, mannitol, aminophylline Increase: lithium level—ACE inhibitors Increase: QT interval—antiarrhythmics, other QT prolongation products Increase: masking of lithium toxicity— β-blockers used for lithium tremor Increase: toxicity—indomethacin, diuret ics, NSAIDs Increase: lithium effect/toxicity—carBA Mazepine, FLUoxetine, methyldopa, thia zide diuretics, probenecid; monitor drug levels Decrease: lithium effects—calcium channel blockers Drug/Herb • Avoid use with kava, St. John’s wort, valerian Decrease: lithium levels—black/green tea, guarana Drug/Food • Significant changes in sodium intake will alter lithium excretion Decrease: lithium levels—caffeine; adjust dose as needed Drug/Lab Test Increase: potassium excretion, urine glu- cose, blood glucose, protein, BUN Decrease: VMA, T3, T4, 131I
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TREATMENT OF OVERDOSE: Induce emesis or lavage, maintain air- way, respiratory function; dialysis for severe intoxication
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Available forms: Caps 150, 300, 600 mg; tabs 300 mg; ext rel tabs 300, 450 mg; oral solution 300 mg/5 mL (8 mEq/5 mL)
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Administer: • Do not break, crush, chew caps, ext rel tabs • Reduced dose to geriatric patients • With meals to avoid GI upset • Adequate fluids (2-3 L/day) to prevent dehydration during initial treatment, 1-2 L/day during maintenance
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Assess: • Mental status: manic symptoms; mood; behavior before, during treatment
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Evaluate: • Therapeutic response: decrease in ex- citement, manic phase
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CLINICAL CONSIDERATIONS
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Patient and caregiver information: • About the symptoms of minor toxic- ity: vomiting, diarrhea, poor coordination, fine motor tremors, weakness, lassitude; major toxicity: coarse tremors, severe thirst, tinnitus, diluted urine; to seek medical care immediately • To monitor urine specific gravity, em- phasize need for follow-up care to deter- mine lithium levels; to monitor lithium levels to ensure effective levels and treatment • Not to operate machinery until lithium levels are stable • To use emergency ID with diagnosis, product used • That beneficial effects may take 1-3 wk • About products that interact with lith- ium (provide list); about need for ade- quate, stable intake of salt and fluids; not to use OTC products unless approved by prescriber • Pregnancy/breastfeeding: that con traception is necessary because lithium may harm fetus; not to breastfeed L
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PHARMACOKINETICS PO: Onset rapid, peak ½-3 hr, half-life 18-36 hr depending on age, crosses blood-brain barrier, 80% of filtered lith- ium reabsorbed by renal tubules, excreted in urine, crosses placenta, enters breast milk, well absorbed by oral method
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