8.8 E) Iii) Toxicology Lithium

Front 1

What determines the need for haemodialysis in acute lithium toxicity?

Back 1

1. Established Renal failure

PLUS

a. GIT symptoms
b. Neurotoxicity

Front 2

Which of the following is incorrect regarding the factors that impair urinary lithium excretion in overdose?
A. Sodium elevation
B. Acute renal impairment
C. Chronic renal impairment
D. Sodium depletion.

Back 2

A. Hypernatraemia impairs lithium excretion.

Front 3

Which is incorrect regarding lithium ?

A. It is a monovalent cation
B. It is a direct irritant to the GI mucosa.
C. Peak serum levels occur after 6 hours
D. Tremor is the first sign of Neurotoxicity

Back 3

C. Within 4 hours.

Front 4

Which is incorrect regarding the management of acute lithium toxicity?
A. Haemodialysis is reserved for those with established renal failure

B. A serum lithium level < 3.5 mmol/L and no Neurotoxicity requires no active intervention.
C. Acute and Chronic lithium toxicity are distinct Clinical entities, with

different indications for Haemodialysis.
D. In the settng of normal renal function, IV fluids and a urine output

of > 1mL/kg is appropriate management.

Back 4

B. Level < 2.5 mmol/L

Front 5

Which is incorrect regarding lithium toxicity?
A. Elimination is entirely by the kidney.
B. The "Hansen and Amdisen" Classification for chronic toxicity has 3 grades
C. Gastrointestinal symptoms can be prominent in chronic lithium

toxicity.
D. The most common causes of impaired lithium excretion are

dehydration and drug interactions.

Back 5

C. GIT Symptoms are not prominent in

chronic Li+ toxicity.

Front 6

Detail the Grades of Hansen and Amdisen

Classification for Chronic lithium toxicity.

Back 6

Grade I = mild = tremor + agitation +hyperreflexia + weakness

Grade II = moderate = Stupor + hypotension + Hypertonia

+ rigidity
Grade III = Severe = Convulsions and coma + myoclonus

Front 7

List the causes of chronic lithium toxicity.

Back 7

1. Dehydration
2. Impaired renal function
3. Drug interactions
4. Diabetes insipidus

Front 8

What drugs can impair lithium excretion?

Back 8

1. NSAIDS
2. ACEI
3. SSRI
4. Thiazide diuretics

5. Acetazolamide

6. Theophylline / Aminophylline

7. Carbamazepine

8. Metronidazole

9. Calcium Channel Blockers (CCB)

10. Antipsychotics

[ Haloperidol ; quetiapine ; olanzapine ; clozapine ; risperidone ]

Front 9

Which of the following is incorrect regarding chronic lithium toxicity?
A. Serum levels correlate well with Clinical severity

B. Serum level > 2.5 mmol/L PLUS Neurological dysfunction

= haemodialysis.
C. Grade II toxicity = Seizures and coma.
D.There is no antidote for lithium toxicity.

Back 9

C. Grade III = seizures and coma

Grade II = hypotension + stupor + hypertonia + rigidity.