U2vi: Outline the pharmacology of glucagon
Glucagon
Glucagon
Chemical
Polypeptide hormone extracted from α cells of pancreas
Use
- Hypoglycaemia rescue
- β-blocker OD
Presentation
- 1mg/mL pre-filled syringe
- 1mg/10mg powder reconstituted with H2O in vials
Dose
- 1 – 2mg IM (hypoglycaemia)
- 5mg → 5mg IV bolus → infusion (β-blocker OD)
Route
IV/IM
Onset
8 – 10 mins IM
1 min IV
DoA
↑BSL lasts 30 mins
MoA
- Agonist of glucagon receptor
- GS GPCR
- ↑Adenyl cyclase activity
- ↑cAMP → protein kinase cascade
PD
(systems)s
- CVS
- +ve inotropy
- +ve chronotropy
- ENDO
- ↑glycogen breakdown
- ↑gluconeogenesis
- ↑ketogenesis
- ↑protein + fat catabolism
- ↑BSL + ketones
- GI
- ↓tone
- Sphincter relaxation
- CNS
- ↑catecholamine release
- Hunger
- Tremor
- Agitation
PK
A
IV 1 – 3min
IM 10min
Orally degraded
D
VD 0.25L/kg
M
Rapid proteolysis in plasma, liver, kidneys
E
t½ 8min
Adverse Effects
Vomiting, diarrhoea, hyperglycaemia, hypokalaemia