Ophthalmic pharmacology Flashcards
When putting drops in eyes - how much volume is retained on the surface?
Delivery volume of eye drops is 50μl (20 drops in 1ml)
Only 20-30μl is retained on surface of eye
If applying drops, how many drops should be applied at a time and why?
1 drop because this is a single dose
How many minutes should be left between administration of different topical drugs?
5 - 10 minutes
What topical antibacterial drugs are licensed for ophthalmic use?
- fusidic acid
- gentamicin
- chlortetracycline
What oral antibiotics are useful in ophthalmology?
- clindamycin
- doxycycline
What oral anti-bacterials may cause ocular toxicity?
- sulphonamides
- enrofloxacin
When are anti-viral drugs used on ophthalmology?
For feline herpesvirus
Topical
- ganciclovir
- aciclovir
Oral
- famciclovir
What topical anti-inflammatory and immunomodulatory drugs are available for eye conditions?
- prednisolone
- dexamethasone
- diclofenac and flurbiprofen
- ciclosporin
What are the 2 mechanisms of action of anti-glaucoma drugs?
- reduce aqueous humour production
- increase aqueous humour outflow
When would you use prostaglandin analogues in eyes?
- Emergency treatment of acute primary glaucoma
- Postoperative ocular hypertension
- Chronic glaucoma - Most effective drug at reducing IOP; can reduce high IOP to safe level within 60-90min of application
Why do we need to be careful when using prostaglandin analogues if uveitis is present? What are other contraindications?
- cause disruption of the ocular blood-aqueous barrier (BAB)
- Disruption of the blood-retinal barrier results in retinal edema
- retinal hemorrhage
- detachment of the neurosensory retina
Contraindications
- anterior lens luxation
- pregnancy
What are the 2 purposes of mydriatics?
dilate the pupil, needed for
Diagnostic purposes: examining lens and fundus
Therapeutic purposes: treating anterior uveitis and aiding intraocular surgery
What mydriatic would you use to dilate the pupil to aid fundus examination and why?
Tropicamide - fastest onset of action , shortest duration of action
What mydriatic is most commonly used to treat anterior uveitis and why?
Atropine as has cycloplegic effect
What are the side effects of and contraindications for the use of atropine?
Sinus tachycardia increased IOP Photophobia, or light sensitivity. Decreased tear production. Blurred vision.
Contraindications: primary glaucoma, lens luxation, KCS,
