Psychic. Drugs Flashcards
1
Q
How is Lithium similar to Sodium in the human body?
A
- both eliminated by the kidneys
2. mostly reabsorbed in the Proximal Tubule
2
Q
Who is at risk of Lithium toxicity?
A
- those with renal impairment
- those who are volume depleted (will filter LESS plasma)
- elderly patients (low GFR)
3
Q
What drugs are said to raise Lithium levels and how?
A
- THIAZIDE DIURETICS (decr. GFR)
- ACE inhibitors (decr. GFR)
- NSAIDs ( decr. renal perfusion)
4
Q
What drug is said to DECREASE lithium levels?
A
- Potassium-Sparing diuretics
5
Q
What are the ACUTE effects of lithium?
A
TREMOR
- Symmetric
- hands and arms
6
Q
What are the long-term effects of Lithium?
A
- hypothyroidism (lithium is goitrogen; stops release of thyroid Hormones > enlarged thyroid by stimulation)
- Cardiac problems
- Nephrogenic diabetes insipidus
7
Q
What is the pathological consequence of Lithium?
A
-chronic tubulointerstitial nephropathy (inability to CONC. the urine- does NOT respond to ADH) -therefore very DILUTE urine > POLYDYPSIA and POLYURIA - normal or INCREASED serum sodium
8
Q
Which form of Diabetes Insipidus does not respond to vasopressin?
A
Nephrogenic DI
9
Q
What is the action of Amiloride on Lithium levels?
A
- amiloride blocks the re-absorption of Lithium into the principal cells of the collecting duct by blocking ENaC-channels
- therefore Improves nephrogenic DI
10
Q
What is the effect of Lithium on the heart?
A
- suppresses the SINUS node (therefore sinus node DYSFUNCTION)
- also cause BRADYCARDIA
- SYNCOPE
11
Q
What occurs on consumption of Lithium when pregnant?
A
- Ebstein’s Anomaly
the apical displacement of the tricuspid valve
