Mood Stabilizers and Antiepileptics Flashcards
gold standard in treatment of bipolar disorder
Lithium
consitered a mood stabilizer
Lithium
Lithium Mechanism of action
Competes with Na+, Ca+ and Mg+ affecting cell membranes, H2O and neurotransmitters
Lithium volume of distribution
42L, through totoal body water
Lithium excretion
Renal excretion
Lithium and the kidney
- filtered by glomerulus and reabsorbed by the proximal renal tubules
- Proximal tubule reabsorbtion of Lithium and Na+ is compeditive
- Drugs that act directly on the distal tubule will NOT have any effect on the absorbtion of lithium
- If patient has low sodium much more lithium will be absorbed.
labs to monitor with lithium
Electrolytes - if patient gets low sodium more lithium will be absorbed at the proximal convoluted tubule
For anestheia know specifically - Na+, Ca++, Mg++, BUN/Creatinine - kidney function
What does Litium compete with? Where?
Sodium - at the proximal convoluted tubule
What drug will not have any effect on the absorbtion of lithium? Why?
Thiazide diuretics, because they work at the distle tubule and lithium is reabsorbed at the proximal convoluted tubule
What drugs should be avaided with lithium?
Anything that alters renal blood flow will increase plama concentration
avoid NSAIDS
NO TORRIDOL
Lithium and Cardiovascular side effects
T-wave changes, flattening or inversion
However, there are NO clinical effects with these changes
Renal side effects of lithium
- Evaluate renal side effects every 6 months
- Polydypsia and poluria; >3L/day (think Na)
- Imparied renal concetration r/t decreased ADH sensitivity
Lithium side effect more common in females
hypothyroidism
- new onstet psoriasis/acne
- Hand tremor
- sedation
- memory disturbances/cognitive slowing
- polydypsia/polyurea
- Twave flattening/inversion
Lithium side effects
Lithium and anesthesia
anesthesia requiremnents may be decreased and non-depolarizing muscle relaxants effects prolonged- r/t NA manipulation
- Sedation
- Nausea
- Skeletal musle weakness
- AV hear block
- seizure
- confusion in elderly
Signs of MILD lithium toxicity
Significant Lithium toxicity
- Medical emergency
- Aggressive treatment
- Hemodialysis
- Osmotic diuresis (mannitol)
- IV bicarbonate (ion trapping - lithium is given as lithum salt- means it is acidic)
When can seizures develop with lithum?
Greater than 2 mEq/L
Lithium therepeutic range
1 -1.2 mEq/L
Very Narrow therepeutic range
Lithium and pre-op cardiovascualr testing
Get an EKG - lithium can cause t wave depression and inversion and need to know so you can identify intraop changes and ischemia