Users

Lithium monitoring

Affected Drug

• N05AN01 Lithium

Baseline

Baseline: TSH, Calcium, CBC, electrolytes, BUN/SCr, ECG (if >45 or CVD)

Follow-up

Follow-up: Q6mo: TSH, CBC, electrolytes, BUN/SCr, Lithium level Q2yr: Calcium Q5yr: ECG (if >45 or CVD) Drug Levels (bipolar disorder): 5 days after starting then weekly for 2 weeks then every 6 months or when new drug initiated Addendum Jan 23, 2012 (D Chan): Researchers examined some 385 studies, ranging from randomized controlled trials to case reports, to measure lithium's effects on renal, thyroid, and parathyroid function, weight gain, hair and skin disorders, and teratogenicity. Among the findings: Lithium's effects on glomerular filtration rates and urinary concentrating ability were small; data on renal failure were scarce, but the absolute risk was small. The rate of hypothyroidism was increased. Blood calcium levels and hyperparathyroidism were also increased with lithium. There was no increased risk for congenital malformations. The authors recommend monitoring calcium levels before therapy and assessing renal and thyroid function and calcium levels annually. Regarding pregnancy, clinicians should counsel women about the uncertainty surrounding lithium and birth defects, taking into account the risks for mood instability if treatment is withdrawn. Ref: http://www.thelancet.com/journals/lancet/article/PIIS0140-6736%2811%2961516-X/abstract

Important Interactions

• Drugs: benazepril, captopril, enalapril, fosinopril, lisinopril, perindopril, accupril, ramipril, Mavik
  Interaction Increases lithium levels by 35% causing possible toxicity
• Drugs: NSAIDs-diclofenac, arthrotec, diflunisal, etodolac, fenoprofen, flurbiprofen, ibuprofen, indomethacin, ketoprofen, mefenamic acid, nambutone, piroxicam, sulindac, tolmetin
  Interaction Increases lithium levels (>100% with some NSAIDs) causing possible toxicity.
• Drugs: caffeine
  Interaction Decreases lithium levels. May worsen tremor.
• Drugs: thiazide and K sparing diuretics: acetazolamide • AMILORIDE • bumetanide • CHLORTHALIDONE • DEMECLOCYCLINE • DESMOPRESSIN ACETATE (DDAVP) • dopamine • FUROSEMIDE • HYDROCHLOROTHIAZIDE • mannitol • metolazone • SPIRONOLACTONE • TRIAMTERENE
  Interaction Increases lithium levels
• Drugs: beta blockers: acebutolol, atenolol, betaxolol, bisoprolol, carvedilol, labetalol, metoprolol, nadolol, propranolol, timolol
  Interaction Increases lithium levels. May improve tremors

Details

Conditions	System	Monitoring		ADE	Incidence	Recommendation
		Baseline	Follow-up
	CNS	Physical Exam	PRN for signs & symptoms	tremors, incoordination, weakness, nystagmus	30-60%	Check Li level, reduce dose, eliminate caffeine, consider BB
	Cardiac	ECG (if >45 or CVD)	Every 5 years (if >45 or CVD)	qrs widening, benign t wave changes, bradycardia	20-30%	Clinical judgement
	Renal	Electrolytes, BUN, SCr	Every 6 months	polyuria, polydipsia, diabetes insipidus	Up to 60%	Usually reversible, consider D/C
				renal failure	uncommon	consider D/C, consider consult nephrol
	GI	Physical Exam	PRN for signs & symptoms	nausea, vomiting, diarrhea	20-50%	Administer with food, consider slow release formulation
	Endocrine	TSH: Calcium: Physical Exam	Every 6 months: Every 2 years: PRN for signs & symptoms	hypothyroidism	Up to 30%	Initiate levothyroxine
				hyperparathyroidism, hypercalcemia:	10-40%	Clinical judgment
				irregular or prolonged menstrual cycles	15%	Clinical judgment
	Hematologic	CBC	Every 6 months	leucopenia, leukocytosis	2-10%	Generally transient, use clinical judgement

References

• Yatham LN et al. Canadian Network for Mood and Anxiety Treatments (CANMAT) guidelines for the management of patients with bipolar disorder: consensus and controversies. Bipolar Disord. 2005;7(Suppl 3):5-69
• Bezchlibinyk-Butler, KZ, editor. Clinical Handbook of psychotropic drugs, 17th edition. Hogrefe and Huber Publishers; 2007
• Gray J, editor. Therapeutic Choices, 5th edition. Ottawa: The Canadian Pharmacists Association; 2007