MH is a 12 year old girl with bipolar disorder who is currently being treated with lithium citrate equivalent as lithium carbonate 450 mg once daily as a part of her drug therapy.
Patient’s lithium came back as 0.5 mmol/L (aim for 0.8-1.0) for active mania.
MH is currently receiving lithium citrate solution dosed in equivalents of lithium carbonate. However, upon discharge she will likely switch to a capsule formulation. Thus, it is suggested that we dose to the nearest dose available in capsules. For MH this would be 750 mg/day.
As MH is currently receiving 450 mg, I suggest we increase to 600mg and reassess the lithium concentration. I do not currently recommend a 750 mg increase from 450 mg, to allow us to keep a close monitoring on MH and ensure that she does not experience any lithium toxicities. Based on this recommendation of 600 mg daily, I recalculated that the 12-hour post-level concentration predicted would be 0.7 mmol/L.
I spoke with the attending psychiatrist and wrote the subsequent note in the chart.
Clinical Pharmacist Note, re: lithium levels
Oct 28, 2016
Patient is currently receiving lithium citrate equivalent to lithium carbonate 450 mg PO QHS (since October 24, 2016). Level taken appropriately after the 4th dose (October 24th at 09:40) was 0.5 mmol/L (usual target is 0.8-1.0 mmol/L). A dose increase to lithium citrate equivalent to lithium carbonate 750 mg PO QHS may be necessary to target 0.8-1.0 mmol/L. At this time it would be appropriate to try an increase of lithium citrate equivalent to lithium carbonate 600 mg PO QHS, which would likely result in a 12-hour post-level of 0.7 mmol/L. Discussed with attending psychiatrist.
– Iona Berger, Pharmacy Resident
Update: Patient has been on lithium citrate equivalent to lithium carbonate 600 mg PO QHS as suggested as above and a post-12 hour level after the 4th dose of the new dosing regimen was taken. As I had predicted (yay!) the level came back as 0.7 mmol/L. Based on this we continued with our plan as stated above to increase the dose to lithium citrate equivalent to lithium carbonate 750 mg PO QHS.