LITHIUM Flashcards
LITHIUM INDICATIONS
Treatment and prophylaxis of:
- Mania
- Bipolar disorder
- Recurrent depression
- Aggressive or self-harming behaviour
BRAND NAMES
CAMCOLIT
PRIADEL
Therapeutic drug monitoring
2 Target serum concs
Serum concentrations - Samples should be taken 12 hours after the dose
Maintenance: 0.4–1 mmol/litre
An acute episode of mania: 0.8–1 mmol/litre
Routine serum-lithium monitoring should be performed:
- weekly after initiation and after each dose change until concentrations are stable
- then every 3 months for the first year, and every 6 months thereafter.
Patients who are 65 years and older, taking drugs that interact with lithium, at risk of impaired renal or thyroid function, raised calcium levels or other complications, have poor symptom control or poor adherence, or whose last serum-lithium concentration was 0.8 mmol/litre or higher, should be monitored every 3 months. Additional serum-lithium measurements should be made if a patient develops significant intercurrent disease or if there is a significant change in a patient’s sodium or fluid intake.
MONITORING PARAMETERS
- Assess renal, cardiac, and thyroid function before treatment initiation.
- An ECG recommended in patients with CVD or risk factors
- Body-weight or BMI, serum electrolytes, and a full blood count should also be measured before treatment initiation.
Monitor body weight or BMI, serum electrolytes, eGFR, and thyroid function every 6 months during treatment, and more often if there is evidence of impaired renal or thyroid function, or raised calcium levels.
TOXICITY RANGE
> 1.5 MMOL
Hyponatremia
HYPONATREMIA PREDISPOSES LITHIUM TOXICITY
NAME 5 TOXICITY SIDE EFFECTS ( SICK + TREMOR )
GI EFFECTS - VOMITING + DIARRHEA
FINE TREMOR INCREASING TO A COARSE TREMOR
VISUAL DISTURBANCES
RENAL IMPAIRMENT - INCONTINENCE, POLYURIA
CNS DISTURBANCES - CONFUSION. DROWSINESS
LITHIUM SE
- THYROID DISORDER
- NEPHROTOXCITIY
- RHABDOMYOLYSIS
- QT INTERVAL PROLONGATION
- TERATOGENIC IN 1 ST TRIMESTER OF PREGNANCY
- BENIGN INTRACRANIAL HYPERTENSION
Treatment cessation
Abrupt discontinuation of lithium increases the risk of relapse.
If lithium is to be discontinued, the dose should be reduced gradually over a period of at least 4 weeks (preferably over a period of up to 3 months).
LITHIUM INTERACTIONS
- DRUGS THAT CAUSE HYPONATRAMIA - E.G. DIURETICS, SSRI, CARBAMAZEPINE
- SALT IMBALANCE
- DRUGS THAT CAUSE SEROTONIN SYNDROME
- DRUGS THAT CAUSE QT INTERVAL PROLONGATION
- DRUGS THAT REDUCE SEIZURE THRESHOLD
- RENALLY CLEARED DRUGS ( INCREASED RISK OF TOXICITY)
Patient and carer advice
Patients should be advised to report signs and symptoms of lithium toxicity, hypothyroidism, renal dysfunction (including polyuria and polydipsia), and benign intracranial hypertension (persistent headache and visual disturbance).
Maintain adequate fluid intake and avoid dietary changes which reduce or increase sodium intake.
Lithium treatment packs
A lithium treatment pack should be given to patients on initiation of treatment with lithium. The pack consists of a patient information booklet, lithium alert card, and a record book for tracking serum-lithium concentration. Packs may be purchased from