Lithium Level always low?

verene, MSN · May 12, 2020

Dosing? Have there been any changes to diet or hydration? Is this a new med for the patient or have they previously been at therapeutic levels? Any recent medication changes?

areason4stars, ASN, RN · May 16, 2020

(Sorry I was mistaken on my original post it was above 0.37 once back in Dec. and when I said the other week it was 0.1 it was actually 0.01 )

He has been on Lithium since 12/26/19 300mg BID

Dose change on 4/27/20 to 300mg at am and 600mg at HS

Labs are

12/30/20 0.49

02/03/20 0.29

4/16/20 0.27

5/05/20 0.01

5/11/20 0.37

His only other med is Aripiprazole 15mg q HS started 01/05/20

No changes to diet or Hydration. He has had a regular diet ordered the whole time and water has/is available as needed.

verene, MSN · May 16, 2020

16 hours ago, areason4stars said:
(Sorry I was mistaken on my original post it was above 0.37 once back in Dec. and when I said the other week it was 0.1 it was actually 0.01 )
He has been on Lithium since 12/26/19 300mg BID
Dose change on 4/27/20 to 300mg at am and 600mg at HS
Labs are
12/30/20 0.49
02/03/20 0.29
4/16/20 0.27
5/05/20 0.01
5/11/20 0.37
His only other med is Aripiprazole 15mg q HS started 01/05/20
No changes to diet or Hydration. He has had a regular diet ordered the whole time and water has/is available as needed.

Is he taking any non-psychotropic medication or supplements? When are labs drawn in relation to dosing? Immediate release or extended release formulation? What impact, if any, has this had on symptoms? My guess is 900mg/day may not be enough particularly if this is an adolescent who is closer to adult size.

Also -- why was abilify added?

areason4stars, ASN, RN · May 19, 2020

Thanks for your insight.

No other meds or supplements.

The lab comes out to the facility around 630am but starts on unit 1. This client is on unit 5. It varies depending how many clients have labs ordered that day. I think average is between 7-8am for this client.

The does at HS is st 2200. His am dose is at 8am

Abilify was added for depression according to the MAR.

He is 14 years old so maybe it is just the fact he is closer to adult size. The Dr was guessing it might be an absorption issue.

verene, MSN · May 28, 2020

On 5/19/2020 at 12:24 AM, areason4stars said:
Thanks for your insight.
No other meds or supplements.
The lab comes out to the facility around 630am but starts on unit 1. This client is on unit 5. It varies depending how many clients have labs ordered that day. I think average is between 7-8am for this client.
The does at HS is st 2200. His am dose is at 8am
Abilify was added for depression according to the MAR.
He is 14 years old so maybe it is just the fact he is closer to adult size. The Dr was guessing it might be an absorption issue.

It's sounding like an absorption issue to me based on this information and/or the patient needing a higher dose.

Spurse32 · Jul 1, 2020

I'm in PMHNP school and happen to be learning about lithium so this is good.

According to the FDA, people are often maintained on a dose of 600 TID which is only half of what your patient is taking. This makes me think you need to just titrate up until you reach a therapeutic level between 0.6-1.2, being cautious of any new side effects as you increase the dose. From what I can see, the dosage is not based on weight, as its excreted primarily by the kidneys. So as long as your patient has adequate kidney function, they should be able to handle a higher dose.

The only things that jumps out at me is the lab level on 05/05/2020. That makes me think that he didn't take his dose the day before or something weird happened. But again I'm only a student so I don't have a lot of experience with lithium lab draws and analyzing the results.

Those are just my thoughts :)

JimRN, BSN, RN · Aug 14, 2020

On 7/1/2020 at 6:15 PM, Spurse32 said:
"This makes me think you need to just titrate up until you reach a therapeutic level..."

That's the answer right there. The level has been consistently low since December. The fluctuations aren't really that dramatic considering the time between them. Focus on good lab draws prior to the first dose of the day and titrate. The best evidence says therapeutic dosages lay around 0.5 mEq/kg/day. Run that figure by the patient's weight and see how it compares to the current dosing. Considering Li has about 8 mEq per 300mg, unless I'm mathing wrong, the dose would be statistically adequate for a 48 kg person. Now, that's not a definitive truth but a decent general guide to consider whether the dose is adequate vs. absorption being a problem.

Don't forget to look at renal function too. Just because he's a kid doesn't mean his kidneys can't be insufficient. Ask the doc for GFR, BUN, and Creatinine next time he gets a lithium level.