Lithium

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Questions

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USMLE® Step 2 style questions USMLE

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A 28-year-old man presents to the clinic because of increased thirst and urination for the past week. He has had large volumes of almost clear urine, especially at night. Since symptom onset, the patient has also felt lethargic and confused. Past medical history is significant for bipolar disorder and severe acne. Current medications include lithium, propranolol, aripiprazole, venlafaxine, and isotretinoin. Temperature is 37.0°C (98.6°F), blood pressure is 90/60 mmHg, heart rate is 105/min, and respiratory rate is 10/min. On physical examination, the patient is noted to have decreased skin turgor. Hemoglobin A1c and serum blood glucose are within normal limits. A water deprivation test shows a urinary osmolality less than 300 mOsm/kg after stimulation with ADH. Which of the following medications is most likely responsible for the patient’s current symptoms?  

Memory Anchors and Partner Content

External References

First Aid

2024

2023

2022

2021

Adverse effects/events

from lithium p. 592

Ataxia

lithium toxicity p. 587

Bipolar disorder p. 578

lithium for p. 592

Diabetes insipidus p. 349

lithium p. 592

lithium toxicity p. 587

Ebstein anomaly p. 285, 302, 304

fetal lithium exposure p. 632

lithium p. 592

Hypothyroidism p. 344, 345

lithium p. 592

Lithium p. 592

for bipolar disorder p. 578, 724

diabetes insipidus and p. 248, 349

hypothyroidism p. 345

prenatal exposure p. 304, 304

teratogenicity p. 632

therapeutic index of p. 233

thyroid functions with p. 248

toxicity of p. 587

Nephrogenic diabetes insipidus p. 213, 349

lithium toxicity p. 587

Polyuria p. 618

lithium as cause p. 592

Pregnancy p. 651

lithium in p. 304, 304

Teratogens p. 632

lithium as p. 592

Vomiting

lithium toxicity p. 587

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Transcript

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Lithium is mainly used for the treatment of bipolar disorder, which is a mental disorder characterized by periods of lowered mood and depression; as well as periods of heightened mood and mania.

Although the mechanism of action is relatively unknown, lithium acts as a mood stabilizer, that can smooth out the highs and lows they experience.

Alright, the average healthy individual might have normal ups and downs throughout their life. They can feel happy on a sunny day or a bit down when it’s raining outside.

They might also have some extreme highs, like when they meet the love of their life, and they might even have some pretty serious lows after losing a job or a person they were close to.

However in bipolar disorder, which used to be called manic depression, the patient has dramatic shifts in emotions, mood, and energy levels: moving from extreme lows to extreme highs.

These shifts usually happen over several days or weeks.

The low moods are identical to those in major depressive disorder, also known as unipolar depression.

Individuals with this feel hopeless and discouraged; have a lack of energy and mental focus; and have physical symptoms, like eating and sleeping too much or too little.

But along with these lows, they have periods of high moods as well, which are called manic episodes or hypomanic episodes, depending on their level of severity.

In a manic state, people feel energetic; overly happy and optimistic; or even euphoric with really high self-esteem.

And on the surface, these might seem like very positive characteristics, but when an individual is in a full manic episode, these symptoms can reach a dangerous extreme.

Patients experiencing mania behave recklessly, they can have pressured speech, where they talk constantly at a rapid-fire pace, or they might have racing thoughts, and feel as if they don’t need sleep.

Manic episodes also include delusions of grandeur, for example they might believe that they are on a personal mission from god, or that they have supernatural powers.

Now, the exact underlying cause of bipolar disorder isn’t known, but it’s thought that both genetic and environmental factors play a part.

Sources

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  2. "Rang and Dale's Pharmacology" Elsevier (2019)
  3. "Goodman and Gilman's The Pharmacological Basis of Therapeutics, 13th Edition" McGraw-Hill Education / Medical (2017)
  4. "Timing of onset of lithium relapse prevention in bipolar disorder: evidence from randomised trials" Br J Psychiatry (2018)
  5. "Lithium: still a major option in the management of bipolar disorder" CNS Neurosci Ther (2012)
  6. "Lithium Use in Pregnancy and the Risk of Cardiac Malformations" N Engl J Med (2017)