Ocular Pharmacology (Done) Flashcards
Most ocular drugs are formulated as ____________ because this formulation allows better penetration and bioavailability
Weak bases
Sympathetic cell bodies are located in the ___________ regions of the CNS.
Thoraco-lumbar regions
Parasympathetic cell bodies are located in the ___________ regions of the CNS.
Cranio-sacral regions
Which outflow mechanism does Pilocarpine act on for glaucoma?
Pulls on scleral spur, opening up the TM for increased outflow and decreased IOP
What are the 4 INDIRECT acting cholinergic Agonists?
- Neostigme
- Pyridostigmine»treats MG
- Edrophonium»diagnosis of MG
- Echothophate
Aside from treating glaucoma, what else is Pilocarpine used for?
- Utilized after angle closure attack in preparation for LPI
- 1% pilocarpine used to differentiate 3rd nerve palsy from a sphincter tear–3rd nerve palsies will constrict with pilocarpine
- 0.125% pilocarpine used in diagnosis of Adie’s Tonic pupil
What are the main side effects of Pilocarpine?
> > Browaches, headaches, and myopic shifts, cataracts, retinal detachments, and secondary angle-closure glaucoma
What do Cholinergic Antagonists block in the nerve?
These drugs block Ach at muscarinic sites in the ciliary body and iris (increase sympathetic effects)
Why is Scopolamine more likely to have CNS toxicity?
Penetrates the blood brain barrier better
What 3 junctions make up the blood-aqueous barrier?
- Iris vessels
- Schlemm’s canal
- Tight junctions of NPCE (ciliary body)
Tropicamide has the fastest onset and shortest duration of mydriatic effects
»It has a much stronger ________ than ________ effect.
Mydriatic than cycloplegic effects
There are 3 classes of SYSTEMIC drugs that are cholinergic antagonists»1) Anti-psychotics 2) Anti-depressants 3) Anti-Histamines»what are they all?
1) Chlorpromazine, Thoridazine
2) Amimphtyline, Imipramine
3) Diphenhydramine (Benadryl), Bropheniramine, Chlorpheniramine, Promethazine
What symptoms will be present if a patient has Atropine toxicity?
Dry mouth, dry flushed skin rapid pulse, disorientation and fever due to CNS effects on hypothalamus
What is Atropine’s onset time and duration of cycloplegic effects?
60-180 minutes onset and 7-12 days duration
Why is cyclopentolate favored in clinic over Atropine and Homatropine?
better cycloplegic effects than homatropine, but similar to atropine except faster onset w/ less duration of action
»can use to treat anterior uveitis as well along with Homatropine
Why is Homatropine, or any cycloplegic for that matter, used to treat anterior uveitis?
Dilates the pupil and keeps the iris MOBILE, which decreases the likelihood of posterior synechiae formation»also reduces pain by paralyzing the ciliary and sphincter muscles
What role does Botox play at the neuromuscular junction?
Blocks the release of Ach
What system does Phenylephrine target? what are all of its clinical uses?
alpha 1 agonist w/ no effects on B receptors»dilation WITHOUT cycloplegia, palpebral widening (acts on Muller’s muscle to retract lid), diagnosing Horner’s syndrome, confirming episcleritis diagnosis, 10% used to break posterior synechiae
What are the 2 main non-specific adrenergic agonists?
Naphazoline and Tetrahydrozoline (Visine)–which acts on alpha 1
When is Phenylephrine contraindicated?
patients taking MOAI’s, TCA’s and atropine
|»_space;also in patients with Grave’s disease
What effect does Naphazoline and tetrahydrozoline have on conjunctival blood vessels?
Constricts blood vessels»over time can cause dilation because of alpha effects on radial muscle.
What is the MAIN effect that alpha 2 agonists (apraclonide, brimonidine) have on aqueous humor outflow?
- Decreases aq. humor production
2. Increases uveoscleral outflow
What is the trade name of Brimonidine?
Brimonidine has show ___________ properties in rate nerve model.
Alphagan 0.2%, neuroprotective properties
In the past, Alphagan caused 30% of patients to develop _______________.
Follicular conjunctivitis
Brimonidine is contraindicated in patients taking ____________.
MAOI’s
What is the acronymn for diseases causing FOLLICLES to appear in the conjunctiva?
“CHAT”»chlamydia, herpes, adenovirus, and toxic
How can Brimonidine be effective in patients with post-refractive LASIK complaints?
Brimonidine causes MIOSIS and can be used to reduce glare, halos, and other night vision symptoms in these patients.
What is Apraclonidine used for?
Alpha 2 agonist with limited alpha 1 activity. used to control IOP spikes before and after ocular surgery. Also used during an acute angle closure attack, as well as in Diagnosis of Horner’s Syndrome
»Remember, Tachyphylaxis–not effective long-term
In what lighting setting will Horner’s syndrome be most evident?
Aniso will be greater in DARK, because the miotic pupil will have a dilation lag
What effect will Apraclonidine have on the pupil of a Horner’s syndrome patient?
It will cause the miotic pupil to DILATE!»in normal patients it will have no effect
What effect will Cocaine have on the pupil of a Horner’s syndrome patient?
Cocaine will have NO EFFECT on the miotic pupil in Horner’s patients
»Normal patients cocaine will DILATE
If a patient with Horner’s fails to dilate upon installation of Hydroxyamphetamine, what does this indicate?
It means it is most likely a POSTganglionic neuron that is damaged.
If a patient with Horner’s DILATES upon installation of Phenylephrine, what does this indicate?
It means the patient has a POSTganglionic lesion
What is the most common B-blocker used for glaucoma treatment?
Timolol
What is the main purpose of B-blockers?
They act primarily on B-receptors (mainly B2) in the NPCE to DECREASE aq. production