Opthalmic drugs & systemic effects Flashcards
Name the five category of drugs used to treat the eye
Mydriatic agents Cycloplegic agents Glaucoma agents Intraocular agents Local anesthetic agents
Mydriatic agents cause
pupillary dilation on the dilator muscle of the iris
Name two mydriatic drugs
phenylephrine
tropicamide
Phenylephrine’s MOA includes
pupillary dilation and capillary decongestion due to alpha-1 agonism without cycloplegic effects
Phenylephrine’s SE includes
Bradycardia
Hypertension
Tremors
HA
Tropicamide exerts its effects as an
antimuscarinic
Cycloplegic agents are classified as ——— that exert its effects by
parasympatholytic compounds
temporary paralysis’ ciliary muscles and muscles of accommodation
*used frequently in phacoEmulsificaton procedures
Name three cycloplegic agents
Homoatropine
Atropine
Cyclopentolate
Atropine causes both
mydriasis and cyclopegia
Atropine SE include
Irritability and delirium (crosses BBB) Tachycardia Flushing Dry skin Thirst
Atropine should be used with caution in which patient population
Narrow-angle glaucoma
Glaucoma agents are further classified as
cholinergic agonists (miotics)
adrenergic agents
carbonic anhydrase inhibitors
prostaglandin F2a analogues
cholineric agonists used to tx glaucoma are subdivided into
direct-acting
vs.
indirect-acting
Name two direct-acting cholinergic agonists
Pilocarpine
Carbachol
Name two indirect-acting cholinergic agonsists
physostigmine
echothiophate
*AKA anticholinesterases
What is the MOA of pilocarpine
Miosis via contraction of the iris sphincter and stimulation of ciliary muscle which opens the trabecular meshwork and facilitates the outflow of aqueous humor and decreases aqueous production…Net effect is to lower intraocular pressure.
*causes loss of accomodation
Does pilocarpine cross the BBB
Yes because it is a tertiary amine
Carbachole is a cholinomimetic agent that
reduces intraocular pressure
Physostigmine is an indirect-acting cholinergic agonist that causes
contraction of the sphincter muscle of the iris wihich opens the trabecular meshwork and facilitates the outflow of aqueous humor.
Does physostigmine cross the BBB
Yes bc it is a tertiary amine
Echothiophate is an indirect-acting cholinergic agent that irreversibly inhibits
acetylcholinesterase
*Takes 4-6 weeks required for activity to recover after stopping of echothiophate therapy
What effect does echothiophate have after systemic absorption through the lacrimal apparatus
it covalently bonds with pseudocholinesterases and inhibits its activity.
*prolongs the activity of succinylcholine, mivacurium, and LA ester compounds
What anesthetic agent should be avoided in patients taking echothiophate
Succinylcholine
What effect does echothiophate have as a gluacoma drug
produces miosis, increased outflow of aqueous humor and decreased intraocular pressure
The are two Major SE assocciated with echothiophate
BRONCHOSPASM and Paralysis r/t elevated achetylcholine levels
Name the classification of the adrenergic AGENTS used to treat glaucoma
Dipiverine (epi deriviative)
B-adrenergic antagonists (timolol, betaxolol)
A-adrenergic agonists (apraclonidine, brimonidine)
Timolol is a nonselective beta antagonist that
decreases the production of aqueous humor which decreases intraocular pressure
*Significant conjunctival absorpton so CAUTION in RAD, HF, hypotension
Alpha-adrenergic agonists exerts its effect on glaucoma patients by
postsynaptic alpha-2 binding which decreases aqueous humor production
Does the a-adrenergic agonist Apraclonidine cross the BBB
NO, highly ionized at physiologic pH
Name four carbonic-anhydrase inhibitors
AcetazolAmide
MethazolAmide
DorzolAmide
BrinzolAmide
What are carbonic-anhydrase inhibitors used for
glaucoma and production of mild diuretic
What is the MOA of carbonic Anhydrase Inhibitors
decreases secretion of aq. humor by the ciliary body which decreases intraocular pressure
*inhibits the conversion of carbon dioxide and water to bicarbonate and hydrogen ion, and affects sodium and fluid transport
Name the prostaglandin F2a analogues
IatanoPROST
TrasoPOST
BimatoPROST
UnoPROStone
What is the MOA of the Prostaglandin F2a drugs
Deceases intraocular pressure by increasing uveoscleral outflow of aqueous humor
*Doesn’t have systemic effects so replaced b-adrenergic antagonists
List three intraocular medications
Acetylcholine
Epinephrine
Sulfur hexafluoride/perfluorocarbons
Acetylcholine is used for what purpose in the eye room
used intraocularly after LENSs extraction to produce pupillary constriction
Epinephrine is used for what purpose in the eye room
placed in irrigating soln to provide continuous mydriasis
Sulfur hexafluoride/perfluorocarbons are used for what purpose in the eye room
bubble of sulfar hexa…injected into posterior chamber during vitreous surgery for insufflation of vitreous cavity or tamponade of a detached retina
15 minutes prior to intraocular gas injection what must be done
discontinue nitrous oxide
Nitrous oxide must be avoided for —-days after air bubble injection
5
Nitrous oxide must be avoided for —-days after sulfur hexafluride injection
10
Nitrous oxide must be avoided for —-days after perfluorocarbons injection
30