Lithium therapy

Question 1

What % of patients experience SE?

Answer 1

75% will experience some SE

Question 2

What major dose-related side effects should you mention to the patient starting lithium therapy?

Answer 2

Polyuria
Polydipsia
weight gain
cognitive problems (dulling, impaired memory, poor concentration, confusion) 
Fine tremor
sedation/lethargy
impaired coordination 
gastrointestinal disturbances- Nausea, vomiting, dyspepsida, diarrhoea 
Hair loss
Acne
Peripheral oedema

Question 3

What regular monitoring is required in lithium therapy?

Answer 3

Serum lithium
Thyroid function tests
U/E

Question 4

What is one option for treating the side effect of fine tremor?

Answer 4

Beta blocker

Question 5

What is one option for treating the side effect of peripheral oedema?

Answer 5

loop or thiazide diuretic

Question 6

What is one option for treating the side effect of acne?

Answer 6

Topical or systemic acne

Question 7

What are some approaches for managing the GI side effects of lithium?

Answer 7

Take lithium with meals
use anti-emetic or PPI (omeprazole or lansoprazole)
Switch lithium preparation- lithium citrate or lithium carbonate

Question 8

What are the long term effects of taking lithium?

Answer 8

may affect the kidneys and thyroid gland
>1% develop irreversible kidney failure after 10+ years
5-35% develop subclinical or clinical hypothyroidism, more in women than men, and usually between 6-18 months after commencing treatment

Question 9

What specific advice should you give to women who are starting lithium therapy?

Answer 9

Adverse risks of pregnancy while on lithium
-8x risk of fetus developing Ebstein’s anomaly- congential malformation of the tricuspid valve of the heart in 1st trimester
2/3rd trim: polyhydramnios, premature delivery, thyroid abnormalities, nephrogenic diabetes insipidus, floppy baby syndrome

Question 10

What advice should be given to a woman with mild, stable bipolar disease who wishes to become pregnant?

Answer 10

Lithium dose may be tapered down and stopped pre-pregnancy.

Question 11

What advice should be given to a woman with moderate risk of relapse in bipolar disorder, is on lithium who wishes to become pregnant?

Answer 11

Lithium should be tapered and discontinued during the first trimester

Question 12

What advice should be given to a woman with severe bipolar disorder, on lithium, and wishes to become pregnant?

Answer 12

Lithium should be maintained

• proper informed consent
• appropriate counselling of the risks to the foetus
• prenatal diagnosis
• detailed ultrasound and echocardiography at 16-18 weeks gestation

Question 13

What should you advice patients about lithium levels and toxicity?

Answer 13

Narrow therapeutic index
Upper limit- 1.2 mmol/L
-If >1.5mmol/L most have toxicity symptoms
-If >2.0mmol/L life-threatening toxic effects occur

Early s/s include: marked coarse tremor, poor appetite,nausea, vomiting, diarrhoea, associated lethargy and dehydration.

Later s/s: restlessness, muscle fasciculation, myoglonic jerks, increased muscle tone, ataxia, dyarthria, drowsiness,confusion, hypotension, cardiac arrhythmias, circulatory collapse, seizures, coma.

Advice: ensure adequate hydration and self intake. Lithium levels rise in dehydration.

Question 14

What tests will be done before starting lithium? How often will they have blood tests?

Answer 14

FBC
Renal function- U/Es
Thyroid- TFT
Pregnancy test- if female
ECG

Check lithium after 5 days after initial dose
Then weekly until stable for 4 weeks
Then every 3 month
Then every 6 months

Question 15

What drugs commonly interact with lithium?

Answer 15

anti-epileptics
diuretics
calcium channel blockers