Most modern steroid enemas are foam based - as the likelihood of someone with colitis being able to retain a water based enema is quite low. These act topically applying the steroid directly to the colon - with only small amounts being absorbed into the bloodstream. This makes side effects less likely. The downside is that they can only reach the descending colon and rectum - so for those with extensive colitis oral steroids may be needed. A combination of Entocort and steroid enemas can provide topical treatment to the majority of the colon - again minimizing side effects. As the two main steroid enemas differ quite greatly I will cover them separately.
Prednisolone Acetate Ophthalmic Suspension USP 1%
FOR TOPICAL OPHTHALMIC USE ONLY.
INGREDIENTS: Each mL contains:
Active: prednisolone acetate %.
Preservative: benzalkonium chloride %.
Inactives: dibasic sodium phosphate, polysorbate 80, edetate disodium, glycerin, citric acid and/or sodium hydroxide (to adjust pH), purified water.
USUAL DOSAGE: Two drops topically in the eye(s) four times daily.
WARNING: Do not touch dropper tip to any surface, as this may contaminate the suspension.
Read enclosed insert.
SHAKE WELL BEFORE USING.
STORAGE: STORE UPRIGHT at 8° - 24°C (46° - 75° F).
Alcon Laboratories, Inc.
Fort Worth, Texas 76134 for
Princeton, NJ 08540
Printed in USA
As a glucocorticoid , the lipophilic structure of prednisolone allows for easy passage through the cell membrane where it then binds to its respective glucocorticoid receptor (GCR) located in the cytoplasm. Upon binding, formation of the GC/GCR complex causes dissociation of chaperone proteins from the glucocorticoid receptor enabling the GC/GCR complex to translocate inside the nucleus. This process occurs within 20 minutes of binding. Once inside the nucleus, the homodimer GC/GCR complex binds to specific DNA binding-sites known as glucocorticoid response elements (GREs) resulting in gene expression or inhibition. Complex binding to positive GREs leads to synthesis of anti-inflammatory proteins while binding to negative GREs block the transcription of inflammatory genes.