Lec. 7: Prostaglandins Analogs

Which drug is considered the clinical first line of drug in management of glaucoma?

Prostaglandins

Which of the following is not a various FP receptor prostaglandin drugs?

Timolol

Which prostaglandin drug has a carbonyl group?

Bimatoprost

Which prostaglandin drug has trifluoride group?

Travoprost

Which receptor does the latanoprost, travoprost, bimatoprost, tafluprost or latanoprostene bunod activate on ciliary body?

F2a prostaglandins receptors on the ciliary body

What is a prodrug?

1. An inactive drug converted to active form in the body 

2. “Inactive outside activates to a different structure by biological tissue”

Does all prostaglandin that is latanoprost, travoprost, bimatoprost, tafluprost have similar structures?

Yes

Prostaglandin analogs are lipophilic outside the eye, hence can pass epithelium readily.

True

Prostaglandin analogs are converted to water hydrophilic by corneal enzymes, hence can pass stroma readily.

True

What form of prostaglandin analogs is hydrophilic?

Latanoprost acid

What are the mechanisms of action for prostaglandin analogs?

1. Increase uveoscleral outflow

2. Slightly increase conventional outflow

Can prostaglandin analog reduce aqueous production?

No

Can prostaglandin analog increase uveoscleral outflow?

Yes

Can prostaglandin analog increase conventional outflow?

Slightly but mainly with latanoprostene bunod

Which drug can nullify the effect of prostaglandin analog by constricting the ciliary muscle?

Pilocarpine

Which corneal enzyme converts Latanoprost, Travoprost, Tafluprost into latanoprost acid?

Cellular estrase

Which corneal enzyme converts bimatoprost into acidic form?

Amidase

Which of the following is not the side effects of prostaglandin analogs?

Mydrasis

What drug class for lowering IOP is not the first choice in individuals with active inflammation?

Prostaglandin analogs

What drug class for lowering IOP is not the first choice in individuals with post-operative complications?

Prostaglandin analogs

What drug class is discontinued prior to performing cataract surgery?

Prostaglandin analogs

How long should you discontinue prostaglandin prior to cataract surgery?

A month

What are the advantages of night time instillation of prostaglandin analogs?

Better IOP control and reduces the redness side effect bc youre gonna go to bed soon anyway

Iris color changes are related to what with the use of prostaglandins?

Increase melanin in melanocytes not increase in cell number 

What are the effects of use of prostaglandins on eyelashes and ocular adnexa?

Increased length, thickness, number, and pigmentation

What are the type of peri-ocular skin changes that are observed due to spill over of the drugs?

Hyperpigmentation of eyelids and periorbital skin 

What changes are observed due to long term use of prostaglandins on upper eyelid sulcus and why?

Deepening of the upper eyelid sulcus due to orbital fat atrophy 

What are the reasons for activation or occurrence of uveitis after use of prostaglandins? 

They can potentially break down blood aqueous barrier

What are the risk factors for development of cystoid macular edema after the use of prostaglandins?

Open posterior capsules, recent intraocular surgeries, iritis, complicated surgery with vitreous loss

Does the use of prostaglandin analog influence blood pressure?

No

What is the half life of prostaglandins?

17 mins

How are prostaglandins removed from systemic circulation?

kidneys

When using two drugs in the same eye, what is an ideal amount of time to space them?

5 minutes

On average how much intraocular pressure lowered when using prostaglandin analogs? 

30%

Name the drug classes that can be used additional to prostaglandin and provides additivity or additional lowering of IOP?

All

Adding beta blockers to prostaglandin can provide what additional percentage of IOP lowering?

14% drop

Adding dorzolamide to prostaglandin can provide what additional percentage of IOP lowering?

15% drop

Adding adrenergic agonists to prostaglandin can provide what additional percentage of IOP lowering?

15% drop

Adding prostaglandin to a patients eye already using topical carbonic anhydrase inhibitor therapy can provide what additional percentage of IOP lowering?

15-24% drop

Which drug class in eye is contraindicated when a patient is using prostaglandin analogs?

Miotics like pilocarpines

Name the fixed combination therapy that is available currently with latanoprost in USA?

Xalaxom QD (combination of latanoprost and timolol) 

Which of the following is not an advantage of fixed combination therapy?

Increase side effects

What percentage of drop in IOP is considered not enough and patient is labelled as a prostaglandin non responder?

<10%

Which prostaglandin drug donates nitric oxide as it is metabolized in eye?

Latanoprostene bunod

What changes in the trabecular meshwork are caused due to nitric oxide?

Relaxation of the TM → increased outflow

Compared to latanoprost on average how much additional IOP lowering can be seen when using latanoprostene bunod?

1 mmHg

What is the most common side effects of using latanoprostene bunod? 

Conjunctival hyperemia

What is the best dose and time of application for prostaglandins?

Once daily at night

Is there a difference in latanoprost versus travoprost in efficacy of drug in lowering IOP?

Similar efficacy

Is there a difference in latanoprost versus bimatoprost in efficacy of drug in lowering IOP?

no

Is there a difference in latanoprost versus latanoprostene bunod in efficacy of drug in lowering IOP?

Latanoprostene bunod lowers IOP ~1mmHg more 

What are the indications to use prostaglandin analogs?

All of the above