Recurrent bipolar depression

1. In patients of average weight (70 kg) an initial total daily dose of 1,018–3,054 mg Lithium citrate (equivalent to 400-1,200mg Lithium carbonate which is 10-30ml of liquid) should be given in divided doses, in the morning and in the evening.

When changing between lithium preparations, serum lithium levels should first be checked, then lithium therapy commenced at a daily dose as close as possible to that of the other form of lithium. As bioavailability varies from product to product (particularly with regard to slow release preparations) a change of product should be regarded as initiation of new treatment.

2. Four to five days after starting treatment (and never longer than one week) a blood sample should be taken for the estimation of serum lithium level. Optimal maintenance serum levels may vary from patient to patient.

3. The objective is to adjust the lithium dose so as to maintain the serum lithium level permanently within the diurnal range of 0.5–1.0 mmol/L. Blood samples for measurement of serum lithium concentration should be taken before a dose is due and not less than 12 hours after the previous dose. ‘Target’ serum lithium concentration at 12 hours should be 0.5-0.8 mmol/L. Serum lithium levels should be monitored weekly until stabilisation is achieved. Levels of more than 1.5mmol/L must be avoided.

The liquid should be taken at the same time every day. A double dose to make up for a dose that has been missed should not be taken.

4. Lithium therapy should not be initiated unless adequate facilities for routine monitoring of serum concentrations are available. Following stabilisation of serum lithium levels, the period between subsequent estimations can be increased gradually but should not normally exceed two to three months. Additional measurements should be made following alteration of dosage, on development of intercurrent disease, signs of manic or depressive relapse, following significant changes in sodium or fluid intake, or if signs of lithium toxicity occur.

5. Whilst a high proportion of acutely ill patients may respond within three to seven days after the commencement of therapy with lithium, it should be continued through any recurrence of the affective disturbance. This is important as the full prophylactic effect may not occur for 6 to 12 months after the initiation of therapy.

6. In patients who show a positive response to therapy with lithium, treatment is likely to be long term. Careful clinical appraisal of the patient should be exercised throughout medication.

7. If lithium is to be discontinued, particularly in cases of high doses, the dose should be reduced gradually.

Treatment of acute mania, hypomania and recurrent bipolar depression

It is likely that a higher than normal intake of lithium may be necessary during an acute phase. As a general rule the monitoring should maintain serum levels at 0.8–1.2 mmol/l until acute symptoms have been controlled. In all other details the described treatment schedule is recommended. The dosage needed may vary from patient to patient. Serum lithium levels should be monitored (see above) and should not exceed 1.5 mmol/l. As soon as control of mania or depression is achieved, the serum lithium level should be determined and it may be necessary, dependent on the results, to lower the dose of lithium and to re-stabilise serum lithium levels to the prophylactic dose.