Decreased Na and Lithium Toxicity

Nursing Students General Students

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Specializes in CVICU and Trauma.

Can someone please explain to me the connection between lithium toxicity and hyponatremia? I can't seem to critically think this one. I know it must be simple but I'm just not seeing it. I have checked all my books but all they say is "decreased sodium intake is a common cause of Lithium toxicity". :hdvwl:

~GB

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Specializes in Psych.

From what im reading, they are both reabsorbed in the promixmal tubule of the kidney. So if the patient has hyponatremia more lithium with be reabsorbed.

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Specializes in CVICU and Trauma.

Ok, I think I've got it!

Lithium is a salt therefore the body absorbs more Lithium than it normally would when hyponatremia is present to replace the sodium deficit.

If I am wrong PLEASE correct me!!!!

~GB

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Specializes in Infusion.

I think you are correct. This is interesting to me because my dad took lithium for decades. He developed congestive heart failure from several small hearth attacks. He was given Lasix to reduce his fluid levels and you can guess what went wrong with that. Now I am understanding why the two drug don't go together. Period!

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Specializes in Infusion.

I was going to say yes because the body will compensated for the sodium loss by reabsorbing more of lithium or sodium or whatever is the same size solute. Lithium has such a narrow margin of being effective before it becomes toxic that maintaining sodium levels in the patient is really important.

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Specializes in CVICU and Trauma.
From what im reading, they are both reabsorbed in the promixmal tubule of the kidney. So if the patient has hyponatremia more lithium with be reabsorbed.

I read that too but I still didn't get it. Now I think I do tho ... read my other post and tell me what you think!

~GB

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Specializes in CVICU and Trauma.
I think you are correct. This is interesting to me because my dad took lithium for decades. He developed congestive heart failure from several small hearth attacks. He was given Lasix to reduce his fluid levels and you can guess what went wrong with that. Now I am understanding why the two drug don't go together. Period!

Ah yes, now the diuretic contraindication makes sense too! I just had an "ah hah" moment, lol.

~GB

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Specializes in Psych.
I read that too but I still didn't get it. Now I think I do tho ... read my other post and tell me what you think!

~GB

Makes sense to me. I will ask about when I am at work tonight ( work on a geri psych unit) or will ask when I have my psych rotation, in about 6 weeks

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Specializes in CVICU and Trauma.
Makes sense to me. I will ask about when I am at work tonight ( work on a geri psych unit) or will ask when I have my psych rotation, in about 6 weeks

Thanks! I find if I truly understand a concept, I can pass any test! I don't do well on the premise of "just know that it does this". Let me know what you find out too!

Do you Hesi for your clinical courses by chance? If you do I have a ton of practice materials I could pass down to you for when you get to Psych!

~GB

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Specializes in Psych.
Thanks! I find if I truly understand a concept, I can pass any test! I don't do well on the premise of "just know that it does this". Let me know what you find out too!

Do you Hesi for your clinical courses by chance? If you do I have a ton of practice materials I could pass down to you for when you get to Psych!

~GB

We have a Hesi exam at the end of the semester. Mine will cover Psych, Resp. and peds

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Because u need to stay hydrated when taking lithium. When u are dehydrated it increases it's affect causing toxicity. Therefore being on a diuretic to decrease excess fluid causing hyponatremia it will put u at risk for lithium toxicity

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