Glyceral Trinitrate (GTN)

Question 1

GTN: mechanism

Answer 1

vasodilator

• venous and arterial vasodilation
• reduction in preload(venous return) reducing filling, CO, oxygen demand.
• reduced afterload (art dilation- fall in PVR - reduced back pressure)
• dilation coronary arts

Question 2

GTN: indications

Answer 2

• myocardial ischemia
• cardiogenic pulmonary odema
• hypertension sec. to autonomic dysreflexia

Question 3

GTN: contra

Answer 3

• systolic <100
• HR <40
• HR>130 (Rx STEMI, ischemia or cpo)
• HR> 150 ( Rx autonomic dys)
• VT

Question 4

GTN: cautions

Answer 4

STEMI: involving right venticle (V4R)/ inferior)

small or frail /unstable

poor perfusion(

Dysrhythmia (

erectile dysfunction drug <24hrs

Known aortic or mitral stenosis(?reduced CO)

Question 5

GTN: breast feeding

Answer 5

balance of risk, chances are low that the two will meet

Question 6

GTN: dose

Answer 6

• pain: 0.4mg @ 3-5 PRN (@10mins if caution)
• CPO 0.8 @ 3-5 (@10 if caution)
• CPO: (para/icp may increase dose/frequency with no improve /no hypotension)*
• Auto dys : 0.4 - 0.8 3-5 prn

Question 7

GTN: adverse

Answer 7

hypotension

flushing

headache

tachycardia

light headed

Question 8

GTN: onset

Answer 8

1-2 mins

Question 9

GTN: duration

Answer 9

15 - 30mins

Question 10

GTN preperation

Answer 10

metered dose inhaler 0.4mg

Question 11

GTN : kinetics

Answer 11

• rapidly absorbed from oral mucosa direct to vascular
• metabloised in liver
• (no contra by liver impairment)

Question 12

GTN: interactions

Answer 12

• maybe potentiated with anti hypertensives
• severe/ prolonged hypotension with erectile dysfunciton meds. - all are prolonged hypotensives ( sildenafil citrate used in Rx pulmonary hypertension)

Question 13

GTN: and stemi

Answer 13

used with caution! risks may out way benefits

drop intCO!

see cpgs