U2v: Fludrocortisone
Fludrocortisone
Fludrocortisone
Chemical
Synthetic mineralcorticoid
Use
Postural hypotension
Adrenocortical insufficiency
Adrenogenital syndrome
Presentation
Tablets
Dose
Initially: 0.05-0.1mg od
Maintenance: 0.05-0.2mg od
Variable schedule from bd to thrice weekly
Route
PO
Onset
Variable
DoA
1-2 days
MoA
Replaces endogenous aldosterone
Binds mineralcorticoid receptors in kidneys
Alters gene transcription
↑Na channels on apical side of renal tubule cells & ↑Na/K/ATPase channels on basolateral side
Overall: ↑Na reabsorption & ↓K excretion
Also acts on glucocorticoid receptors but with a much lower affinity
PD
RENAL: sodium and water reabsorption, K excretion
PK
A
Rapid & complete
D
80-85L
70-80% PPB
M
Liver to inactive glucuronide and sulfate metabolites
CYP3A
E
Renally (active – majority, inactive metabolites)
Small amounts excreted in feces
T1/2β 3 hrs
Adverse Effects
CVS: HF, cardiomegaly, oedema, HTN
CNS: delirium, depression, glaycoma
Endo: hypokalaemic alkalosis, hypokalaemia, hyperglycaemia, HPA-axis suppression, cushing’s syndrome, DM, glycycosuria, growth suppression, hirtutism
GI: abdominal distention, gastric & oesophageal ulcers, pancreatitis
Haem: petechia, purpura, bruising
MSK: osteoporosis, myopathy, osteonecrosis,
Derm: acne vulgaris, striae, erythema, hyperpigmentation, maculopapular rash
Multiple drug interactions