Ophthalmic medications are used for a number of conditions such as glaucoma, infection, allergy and inflammation, often on a chronic basis. Generally the drugs used in this manner have good safety profiles, but they do have the potential to cause significant adverse drug events, and can interact with other systemic medications.
Ophthalmic medications pass through the lacrimal sac and have access to the highly vascular nasal mucosa.
Because they avoid first-pass metabolism by the liver the pressure lowering side effect of a single drop of an ophthalmic medication is magnified 10 times when absorbed through the lacrimal sac.
Here's what you can do to prevent systemic absorption from your eye drops
The systemic absorption of ophthalmic medication can be minimised using the “double DOT” technique (Don’t Open Eyes Technique and Digital Occlusion of the Tear duct). This involves closing the eyes and applying pressure with the finger over the lacrimal sac (outside corner of the eye) for 1-2 minutes. This can reduce systemic absorption by up to 70%, thus decreasing the likelihood of significant systemic absorption.
Recommended Robbo, the pharmacist in the great Australian bush.
Health professionals can get more information on the systemic effects of ophthalmic medications from this bulletin by the Repatriation Hospital of South Australia, available via Robbo's bitethedust
|Some examples of the ophthalmic medications that can cause systemic side effects|