Drug Interaction:
Glucorticoids include -
Short acting- Cortisone, Hydrocortisone
Intermediate acting - Prednisone, Prednisolone, Triamcinolone, Methylprednisolone
Long acting- Dexamethasone, Betamethasone
Refer- Dexamethasone
Interacting drugs - summary
+Corticosteroids
Aminoglutethimide/dexamethosone +
possible loss of dexamethosone-induced adrenal suppression
Barbiturates
decreased pharmacolgic effects of the corticosteroids metabolism
through the induction of hepatic microsomal enzymes
Cholestyramine/ Hydrocortisone+
hydrocortisine AUC decreased
Contraceptives Oral-
Hepatic metabolism decreased by OCs, resulting in
increased therapeutic effects or toxicity
Ephedrine /Dexamethasone+
a decreased half-life and increased clearance of dexamethsone
may occur
Estrogens
estrogen coadministration reduce the clearance and
increase the elimination half-life of corticosteroids
Hydantoins
corticosteroids clearance decreased and the AUC increased
resulting in reduced therapeutic effects
Ketoconazole
corticosteroid clearance decreased and the AUC increased
Macrolide Antibiotics/ Methyl prednisolone +
significant decrease in methylprednisolone clearance has been used
to decrease methylprednisolone dose
Rifampicin
corticosteroid clearance increased resulting in decreased
therapeutic effects
Corticosteroids +
Anticholinesterases
anticholinesterase effect antagonised in myasthenia gravis
Anticoagulants oral
anticoagulant dose requirements reduced. Conversely,
corticosteroids may oppose the anticoagulant action.
Cyclosporine
although this combination is therapeutically beneficial for organ
transplant, toxicity may be enhanced
Digitalis glycosides
coadministratin enhance the possibility ofdigitalis toxicity
associated with hypokalemia
Isoniazid
isoniazid serum concentration decreased
Nondepolarising muscle relaxants
corticosteroids potentiate, counteract or have no effect on the
neuromuscular blocking action
Poatssium depleting agents eg.diuretics
observe patients for hypokalemia
Salicylates
corticosteroids will reduce serum salicylate levels and decrease
their effectiveness
Somatrem
growth-promoting effect of somatrem inhibited
Theophyllines
alterations in the pharmacologic activity of either agent occur
Adverse Reaction:
Acute adrenal insufficiency may be precipitated by infection trauma, in patients on long term corticosteroid therapy.
Cushings syndrome, growth retardation in children, osteoporosis and vertebral compression fractures.
Peptic ulceration, haemorrhage and perforation, glaucoma,hyperglycaemia.
GI upsets, nocturia, increased appetite, obesity, facial rounding, increased fragility of skin,
behavioural changes.
Topical applications to skin: Systemic absorption if applied to large areas,broken skin under
occlusive dressing.
Intra articular injection: Aseptic bone necrosis.
Inhalation: Cough, irritation, swallowed inhalation may cause epigastric pain.If no releif with usual dose symtoms may be aggrevated due to hypoxia.