Prednisolone (For Asthma)
Chemical
Synthetic glucocorticoid
Use
Asthma
Presentation
Tablets
Route/Dose
5 – 60mg / day
MoA
- Glucocorticoid receptor AGONIST
- Binds corticoreceptor-ligand complex
- Translocates itself into cell nucleus
- Alters protein DNA transcription
- Inhibits phospholipase A2 (which breaks down phospholipids to give arach. Acid)
- ↓Arach acid
- ↓PG/leukotriene/IL production
- ↓inflam cascade, ↓oedema, ↓capillary leakiness
- (↓airway hyperresponsiveness)
PD
Resp
- Contract engorged vessels of bronchial mucosa
- Potentiate B2 agonist effects
- Inhibit infiltration of asthmatic airways by LC, eosinophils, MCs
GI
- ↑risk of peptic ulcers
- ↓Ca2+ absorption
Renal
- Na+ retention, K+ excretion
CVS
- +ve inotropy & VC by ↑no. of α1 & β adrenoreceptors
Metabolic
- Gluconeogenesis
- Inhibit use of peripheral glucose
- ↑lipolysis
- ↓amino acid → protein
Immune
- Blocks neutrophil & macrophage recruitment
- Blocks lymphokines
- Inhibits all stages of inflammatory process
PK
A
Rapidly & completely, PO or PR
80 – 100% bioavailability
D
PPB 90%
VD 0.35 – 0.7L/kg
M
Liver hydroxylation → conjugation
E
10% doses unchanged in urine
t ½ B 2.5 – 5hrs
Adverse Effects
- Acute withdrawal syndrome
- Cushing’s disease
- Peptic ulcers
- Osteoporosis