Tuesday, October 15, 2013

Lithium Mechanism of Action (MOA)



1.       1st Line Tx Bipolar Disorder
Works like Na+. Blocks Na Channels
-Cell can’t become too positive
-Cell can’t become too negative
Mood Stabilizer (not acute Dz)
Blocks Relapse & acute Maniac Events
2.       Blocks ADH receptors V2
→ Nephro DI
SIADH Tx
3.       Fools kidney: Holds Li, let go Na
→Hyponatremia
Affects Electrolytes & ion transport
4.       Fools Thyroid (Resembles I)
→Hyponatremia
5.       Fools PTH receptors:
a.       ↑Ca+2, ↓PO4
6.       Phospho Inositol Cascade Inhibition
Inhibits dephospholiration of IP3->IP2, IP2-IP1 and IP1-IP
(inositol recycling steps → ↓PIP2)
7.       ↓DA & NE turnover (↓DA ↓ NE ↑Serotonin)

(IP3 is recycled back to PIP2 by the enzymes inositol monophosphate phosphatase (IMPase) and inositol polyphosphatase phosphatase (IPPase); both of which are inhibited by lithium)

Monday, October 07, 2013

Restrictive lung Diseases

Explain all restrictive lung diseases.


Restrictive: interstitial problem (non-bacterial)

- Small stiff lungs (↓VC)

- Trouble breathing IN → FEV1/FVC >0.8

- ABG: ↓pO2 → ↑RR, ↓pCO2, ↑pH

- CXR: reticulo-nodular pattern, ground-glass appearance

- Die of cor pulmonale

- Ex: NM dz (breathing out is passive), drugs, autoimmune dz

- Tx: Pressure support on ventilator, ↑O2, ↑RR, ↑inspiratory time



Obstrucrive Lung Diseases

Obstructive: airway problem (bacterial)

• Big mucus-filled lungs (RV, Reid index = airway thickness/airway lumen)

•Trouble breathing out → FEV1/FVC < 0.8

• ABG: pC02 → RR, pH

• Die of bronchiectasis

Ex: COPD

Tx: Manipulate rate on ventilator  RR expiratory time, O2 only if needed.