Lecture 11 - Medical management of Glaucoma 2 Flashcards
What initial beta blocker lowered IOP but caused corneal anesthesia?
Propranol
Practolo was developed, in the wake of Propranol, even though it didn’t cause corneal anesthesia, what was a major sideffect it created?
Occulomucuataneous syndrome
What type of beta adrenoreceptor causes dilation of bronchi and blood vessels?
Beta 2
OBB’s are what type of beta drug, agonist or antagonist?
Antagonist
What is the mechanism of action of a OBB?
Exact mechanism not known but it will reduce aqueous formation
What type of stimulation of the Ciliary process interfere with?
Tonic stimulation
Note: This is speculative
What type of Glaucoma(s) are OBB’s used for?
OAG, Secondary glaucoma, ACG and Ocular HTN
What type of Betaxolol is not contraindicated for 1. Pulmonary disease
- Bronchial Asthma
- Severe COPD?
Selective OBB’s
True or False. Taking OBB’s twice a day will have a larger impact than once a day?
True
Note: Exception to this rule are:
Isatalol qam
Timoptic XE or GFS (gels) qd
Betagan qd
What is the commonly used non-selective OBB?
Timolol 0.5%
What is the maximal effect regarding Timolol instillation?
12 hours but IOP lowering will stick around for 24 hours
Note: Onset is 30 minutes
When is the best time to to instill Timolol to get the best result?
In the AM
True or False. In all pts, short term escape of timolol will occur?
False. Not all pts but the efficacy of Timolol will decrease over a period of time, due to constant antagonism
What does Long term drift mean?
Control of IOP is not as good as once, as it use to be. Takes about months to year to occur.
What is washout period?
IOP lowering effects may persist for 2 weeks.
Aqueous flow upto 6 weeks
Note: Clinically a 4 week wash out period is acceptable
What are the benefits of using gels and disadvantage of using gels?
Advantage: Improve bioavailability, decrease systemic absorption, and once a day drop
Disadvantage: Blurry vision in the morning, has a preservative
What is the major difference between Istalol vs. Timoptic XE?
Istalol = BAK
Timpotic XE = Benzododdecinium
What does Betaxolol suspension have that the solution does not have?
resin coated beads
Note: Betaxolol is not available in the USA
True or False. You can use a selective BB with pts who have pulmonary disease?
True.
Note: Betxolol can used for this process and is less effective compared to Timolol
What are three benefits of betaxolol properties?
- May possess calcium channel blocker properties
- Thus may have neuroprotectic effect*
- Highly lipid soluble, binds well with plasma proteins
What are three ocular sideeffects of propranolol?
Discomfort, Burning and stinging
What OBB is associated with granulomarous uveitis?
Metipranolol
What are 4 local sideffects regarding BAK usage?
- Decreased tear production
- Decreased goblet cell density
- Dry eye symptoms
- Ocular cicatrical pemphigoid.
Which method do OBB’s enter the systemic system?
Nasolacrimal system
True or False. One of the major CNS adverse effects is the decrease in libido in men.
True but its also true in women aswell
What do OBB’s do to cardiovascular effects?
Reduce blood pressure
Bradycardia
What receptor is blocked that causes pulmonary effects?
Beta 2 receptor
True or False. OBB’s affect hypoglycemia?
True
Why is clonidine not used in IOP lowering?
Causes sedation, systemic hypotension and narrow therapeutic index
Apraclonidine would be a great IOP recducer but why is it not used?
Very hydrophillic, therefore does not penetrate eyes and BBB
Note: Use Post-laser surgery
Why should you avoid using Brominidine post laser IOP?
It acts as a prophylactic???
Note: Brominidine is contraindicated with pts on MAOI’s
What does Combigan consist of two drugs?
Brimonidine and Timolol
What does neuroprotection mean?
Prevent destructive cellular events and enhance survivial of cells after damage
Note: No glaucoma drug is neuroprotective
What are the 4 criteria to be considered neuroprotective in glaucoma?
1) the agent must have a target in the retina;
Yes they are present
2) it must be neuroprotective in animal models;
3) it must reach neuroprotective concentrations in the posterior segment after clinical dosing;
4) it must be shown to be neuroprotective in controlled clinical trials.
Which older drug is used for ACG with pupillary block?
Pilocarpine - works on anterior tendons of ciliary muscles and other CB structures
and
Contraction of ciliary muscle, which causes unfolding or meshwork and widening of schlemm’s canal
How is pilocarpine absorbed?
By the cornea
Note: Side effects are Stinging and Burning. You will notice intense miosis and constant accommodation as well
What is the pharmacological antagonist for pilocarpine?
Atropine
What family do CAI’s belong too?
Sulfonamide
Hence if someone has a sulfa allergy you don’t give CAI’s then.
What do CAI’s actually inhibit?
Reduction of Bicarbonate ions in posterior chamber
What will occur if you give CAI’s and cannot tolerate the increase in serum ammonia?
Hepatic insufficiency
What drug is known to cause Hirsutism, hairy-ness in women, as a side effect?
CAI’s
What are the two topical CAI’s available to us?
Dorzolamide and Brinzolamide
