Glaucoma Drugs Flashcards
What groups of drugs are used to treat glaucoma?
Miotics
Sympathomimetics
Beta blockers
Carbonic Anhydrase Inhibitors
Prostaglandin Analogues
Hyperosmotic agents
What are miotics also known as?
Parasympathomimetics
Cholinergic agonists
How do miotics reduce IOP?
Increase the rate of aqueous outflow by causing increased trabecular meshwork tension due to ciliary muscle contraction
What is the aim of glaucoma meds?
To reduce IOP, resulting in the maintenance of the current level of vision (bc ganglion cell axons are not being damaged due to high IOP)
What are the contraindications for using miotics?
Anterior uveitis
Iris-mounted IOL
Iridectomy
Prev RD
Secondary glaucoma with extensive obstruction of outflow
What are the side effects of miotics?
Sweating
Bradycardia
Bronchospasm
Hypersalivation
Intestinal colic
Frontal headache
Pseudomyopia (if remaining accommodation)
Constricted visual field
Retinal detachment
What is Pilocarpine available as and what’s its dose?
2% minims
1/2/4% bottles
3-6x daily
What is Pilocarpine’s mode of action?
direct-acting cholinergic agonist
What is sympathomimetics mode of action?
Selective or non-selective adrenergic agonists which reduce aqueous humour production and sometimes increase outflow via the uveoscleral route
What are the contraindications for sympathomimetics?
Closed angle glaucoma (mydriatic so closes the angle further)
Sympathomimetic
What is the mechanism for Brimonidine?
Highly selective alpha2 adrenergic agonist
Sympathomimetic
What is Brimonidine available as? What’s it’s dose?
Name and concentration
Alphagan 0.2% solution
2x daily
Sympathomimetic
What are the possible side effects of Brimonidine?
Hyperaemia
FB sensation
Stinging
Blurred vision
Dry mouth
Headache
Fatigue/drowsiness
Allergic reaction
Reduction in heart rate and BP
Sympathomimetic
What is the mechanism for Apraclonidine?
Selective alpha2 adrenoceptor agonist
Sympathomimetic
What is Apraclonidine available as? What is it mostly used for?
Name and concentration
Iopidine 1% solution
Short term treatment e.g. post surgery
What is Beta blockers mode of action?
Beta receptor adrenergic antagonists which reduce aqueous humour secretion
Where are beta1 receptors located?
Heart and kidney
Where are beta2 receptors located?
Bronchi
What are the systemic side effects of beta blockers?
Bradycardia
Reduced BP
Respiratory difficulty
What are the contraindications for beta blockers?
Obstructive airway disease (e.g. asthma)
Bradycardia
Heart block/failure
Beta blocker
Is Timolol selective?
No - blocks both beta1 and beta2
What are the potential ocular side effects of beta blockers?
Stinging
Burning
Gritty sensation
Beta blocker
What is Timolol available as? What’s the dose?
Name and concentration
Timolol 0.25%/0.5% drops (2x daily)
Timoptol 0.25%/0.5% gel (1x daily)
Tiopex 0.1% gel (1x daily)
Beta blocker
Is Levobunolol selective?
No - blocks both beta1 and beta2
Beta blocker
What is Levobunolol available as? What’s the dose?
Name and concentration
Levobunolol 0.5% drops (1-2x daily)
Betagan 0.5% with 1.4% PVA vehicle drops (1-2x daily)
What does a PVA vehicle do?
Increases the viscosity of the drop, increases contact time of the drug and therefore prolongs release time/effectivity time
Beta blocker
Is Betaxolol selective?
Yes - only blocks beta1
Beta blocker
What is Betaxolol available as? What’s it’s dose?
Name and concentration
Betoptic 0.5% drops or 0.25% Ophthalmic suspension (2x daily)
What combination preparations does Timolol come in?
Combigan (Brimodone 0.2%, Timolol 0.5%)
CoSopt (Dorzolamide 2%, Timolol 0.5%)
Azarga (Brinzolamide and Timolol)
Ganfort (Bimatoprost and Timolol)
Xalacom (Latanoprost 50mg/ml and Timolol 5mg/ml)
Duotrav (Travoprost and Timolol)
How do Carbonic Anhydrase Inhibitors work?
Stop carbonic anhydrase (enzyme) catalysing bicarbonate formation which reduces aqueous humour production
Bicarbonate is an important component in aqueous humour formation
What can carbonic anhydrase inhibitors be used in combination with?
Beta blockers
Sympathomimetics
Carbonic anhydrase inhibitor
Why is Acetazolamide only available as a systemic treatment?
Poor lipid solubility and corneal penetration
Carbonic anhydrase inhibitor
What is Acetazolamide available as?
Name and concentration
Diamox 250mg tablets
Diamox SR 250mg sustained release tablets
Intravenous powder
Carbonic anhydrase inhibitor
What are the side effects of Acetazolamide?
Metallic taste
Digit numbness
Malaise/fatigue
Weight loss
Reduced libido and impotence
GI tract irritation
Altered renal function
Carbonic anhydrase inhibitor
What are the contraindications for Acetazolamide?
Pregnancy
Liver disease
Kidney disorder
Carbonic anhydrase inhibitor
What is Dorzolamide available as?
Name and concentration
Trusopt 2% solution
Cosopt 2% with 0.5% Timolol
Carbonic anhydrase inhibitor
What are the side effects of Dorzolamide?
Localised ocular irritation
FB sensation
Stinging
Blurred vision
Conjunctivitis/lid inflammation
Corneal oedema
Carbonic anhydrase inhibitor
When might Dorzolamide be a useful option?
If beta blocker ineffective
If beta blocker contraindicated (heart and lung disease)
Carbonic anhydrase inhibitor
What is Brinzolamide available as? What’s it’s dose?
Name and concentration
Azopt 10mg/ml drop suspension
Azarga (with Timolol)
What is the model of action of Prostaglandin Analogues?
Promotion of aqueous humour drainage via uveoscleral route by remodelling ciliary muscle extracellular space. This reduces collagen levels in ciliary muscle and surrounding sclera, resulting in reduced resistance to aqueous outflow
Prostaglandin Analogue
What is Latanoprost available as? What’s it’s dose?
Name and concentration
Xalatan 50mg/ml solution (drops) 1x daily at night
Xalacom 50mg/ml with Timolol 5mg/ml 1x daily in morning
Prostaglandin Analogue
What are the side effects of Latanoprost?
Darkening of iris, lids and lashes
Thickening of lashes and increase in number
Mild conjunctival hyperaemia
Prostaglandin Analogue
What pathologies are associated with Latanoprost and Travoprost?
Cystoid Macular Oedema
Anterior Uveitis
Mild punctate epithelial staining
Dendritic corneal epitheliopathy
Herpes simplex keratitis
Prostaglandin Analogue
What is Travoprost available as?
Name and concentration
Travatan 40mg/ml solution
Duotrav (with Timolol)
Prostaglandin Analogue
What are the side effects of Travoprost and Bimatoprost?
Darkening of iris, lids and lashes
Thickening of lashes and increase in number
Mild conjunctival hyperaemia
Headache
Photophobia
Prostaglandin Analogue
What is Bimatoprost available as? What’s it’s dose?
Name and concentration
Lumigan 300mg/ml or 100mg/ml drops 1x daily
Ganfort (with Timolol)
Prostaglandin Analogue
What other use does Bimatoprost have?
Cosmetic lash growth (in US)
Prostaglandin Analogue
What is Tafluprost available as? What’s it’s dose?
Name and concentration
Saflutan 15mg/ml drops (single dose units)
1x daily
For Prostaglandin Analogues, which side effects remain and which reverse?
Iris darkening can continue after ceasing of treatment
Lash and lid darkening normally reverses once treatment stopped
How do Hyperosmotic agents work?
An increase in blood plasma osmolarity causes fluid to move into plasma from the eye (and rest of the body), reducing IOP.
Hyperosmotic agents
What is Mannitol available as?
Concentration and Administration
20% solution administered intravenously
What are hyperosmotic agents used for?
Severely high IOPs that need quick short term reduction
e.g. Acute AC, pre-op IOP reduction, post penetrating trauma IOP reduction
Hyperosmotic agents
What is Glycerol available as?
Concentration and Administration
50% solution administered orally
Hyperosmotic agents
What is the onset and duration of Mannitol?
Onset: 30-60 mins
Duration: Up to 6 hours
Hyperosmotic agents
What is the onset and duration of Glycerol?
Onset: 15-30 mins
Duration: 4-5 hours
Hyperosmotic agents
What is Isosorbide available as?
Concentration and Administration
45% solution administered orally
Hyperosmotic agents
What is the onset and duration of Isosorbide?
Onset: 30-60 mins
Duration: 5-6 hours
What are the side effects of hyperosmotic agents?
Nausea and vomiting
Dehydration
Headache
Confusion/disorientation
Diuresis
Congestive heart failure (if pre-disposed heart issues)
Sympathomimetic
How much can Brimonidine reduce IOP by?
~6.5mmHg
Beta Blocker
What effect does Timolol have on IOP?
25% reduction for 24 hours
Beta Blocker
What effect does Levobunolol have on IOP?
25% reduction for 24 hours
Beta Blocker
What effect does Betaxolol have on IOP?
Lower reduction than Timolol after first month (IOP higher than pxs on Timolol), but same after 1 year
Prostaglandin Analogue
What effect does Latanoprost have on IOP?
25-30% reduction
