OPHTHALMOLOGY DRUGS
Ophthalmic drug administration is the administration of a drug through the eyes, most typically as an eye drop formulation.
What are eye drops?
Eye drops are a sterile solution or suspension of medicine. They are used to produce a local effect directly on the eye.
How to use your eye drops?
1. If your eye drops are a suspension,shake the bottle before using the drops.
2. Wash your hands.
3. Wipe eyes with a clean tissue to clear any residual wateriness or discharge.
4. Take the lid off the bottle.
5. Tip your head back.
6. Gently pull down your lower eyelid and look up.
7. Hold the dropper or bottle above the eye and gently squeeze one drop onto the inside of the lower eyelid, taking care not to touch the eye or eyelashes with the dropper or bottle.
8. Blink your eyes so the liquid spreads over the surface of the eyeball.
9. Wipe away any excess liquid with a clean tissue
Drop (Gutta)‐
⦁ Simplest and more convenient
⦁ Mainly for day time use
⦁ 1 drop=50 microlitre
⦁ Conjuctival sac capacity=7‐13 micro liter
So, even 1 drop is more than enough
Measures to increase drop absorption:
‐Wait 5‐10 minutes between drops
‐Compress lacrimal sac
‐Keep lids closed for 5 minutes after instillation
⦁ 50% drug remains 4 min. after instillation
⦁ 10% drug reach aqueous humour
⦁ Compress NLD to decrease systemic absorption
How to use your eye ointment
1. Wash your hands.
2. Take the lid off the ointment.
3. Tip your head back.
4. Gently pull down your lower eyelid and look up.
5. Hold the tube above the eye and gently squeeze a 1cm line of ointment along the inside of the lower eyelid, taking care not to touch the eye or eyelashes with the tip of the tube.
6. Blink your eyes to spread the ointment over the surface of the eyeball.
7. Wipe away any excess ointment with a clean tissue
Your vision may be blurred when you open your eyes - DON'T rub your eyes. The blurring will clear after a few moments if you keep blinking.
COMMON OPHTHALMOLOGICAL DRUGS
⦁ Antibacterials (antibiotics)
⦁ Antivirals
⦁ Antifungal
⦁ Mydriatics and cycloplegics
⦁ Antiglaucoma
⦁ Anti‐inflammatory agents
Cortico Steroids And NSAIDS
⦁ Ocular Lubricants
⦁ Antihistaminics
⦁ Ocular diagnostic drugs
⦁ Local anesthetics
⦁ Corticosteroids NSAIDs
ANTIBACTERIALS (ANTIBIOTICS)
Penicillins
¡Cephalosporins
Sulfonamides
Tetracyclines
Chloramphenicol
Aminoglycosides
Fluoroquinolones
Vancomycin
1. Used topically in prophylaxis (pre and
postoperatively) and treatment of
ocular bacterial infections.
2. Used orally for the treatment of
preseptal cellulitis e.g. amoxycillin with clavulonate
1. Used intravenously for the treatment
of orbital cellulitis e.g. gentamicin, cephalosporin,vancomycin, flagyl
2. Can be injected intravitrally for the
treatment of endophthalmitis
CEPHALOSPORIN
1 st generation
⦁ Cephalothin, cefazolin, cephalexin
⦁ Active against G+ve and G‐ve
⦁ Not active against MRSA, Enterobacter, Proteus spp, P aeruginosa, Serratia, enterococci
2 nd generation
⦁ Cefamandole, cefoxitin, cefuroxime
⦁ Greater activity against G‐ve : H.influenzae, Enterobacter, Neisseria
3 rd generation
⦁ Cefotaxime, Ceftriaxone, Cefoperazone
⦁ Active against GNR > G+ve cocci : Serratia, Proteus, Ⱦ‐lactamase H influenzae, anaerobe
⦁ P.aeruginosa : ceftazidime, cefoperazone
⦁ Cefotaxime : good penetration blood‐ocular barrier
4 th generation
⦁ Extended spectrum
⦁ Against gram‐positive organisms as 1 st generation
⦁ Greater resistance to beta‐lactamases than 3 rd generation
⦁ Can cross blood brain barrier
⦁ Against nosocomial pathogens
⦁ Cefepime, Cefluprenam, Cefozopran, Cefpirome, Cefquinome
FLUOROQUINOLONES
1st generation
▪ Nalidixic acid
2nd generation
Ciprofloxacin,ofloxacin, lomefloxacin
⦁ Active against G‐ including Pseudomonas spp, some G+
⦁ Not active against Strep pneumoniae
3rd generation
⦁ Levofloxacin
⦁ Same as 2nd
⦁ Active against more G+, Strep pneumoniae
4th generation
⦁ Gatifloxacin (Zymar®), moxifloxacin (Vigamox®)
⦁ Same as 3rd , active against anaerobe
⦁ Useful in bacterial conjunctivitis, corneal ulcer
AMINO GLYCOSIDES
⦁ Mainly against Gm negative bacilli
⦁ Bacterial protein synthesis inhibitors
⦁ Gentamycin—0.3% eye drop
⦁ Tobramycin‐ Pseudomonas 1% eye drop
⦁ Neomycin—0.3‐0.5% eye drop
TETRACYCLINE
⦁ Inhibit protein synthesis
⦁ Active against both gm+ and gm ‐, some fungi and Chlamydia
CHLOROMPHENICOL
⦁ Broad spectrum ,bacteriostatic, gm+/gm‐, Chlamydia
⦁ 0.5% Eye drop, ointment
VANCOMYCIN
⦁ Against MRSA or strep
⦁ Useful in corneal ulcer, endophthalmitis
Polymyxin B + Neomycin
⦁ Against Staph. aureus, Strep spp, GNR
⦁ Useful in surface bacterial infection e.g. conjunctivitis, blepharitis
ANTIVIRALS
Acyclovir
⦁ Inhibits viral DNA synthesis
⦁ Active against HSV I & II, HZV
⦁ Oral, ointment
⦁ Interact with viral thymidine kinase (selective)
⦁ Used in herpetic keratitis
Ganciclovir
⦁ Active against CMV
⦁ Oral, iv, intravitreal
⦁ Useful in CMV retinitis
⦁ SE: BM suppression, renal failure
⦁ Used intravenously for CMV retinitis
Basic fungal classification
a. Filamentous fungi
⦁ Septate = Fusarium, Aspergillus
⦁ Nonseptate = Mucor
b. Yeasts
⦁ Candida, Cryptococcus
Most antifungal drugs act by attacking the membrane sterols of fungi (ergosterol), leaving mammalian sterols (cholesterol) unaffected
INDICATIONS
Fungal corneal ulcer
Fungal retinitis/ Endophthalmitis
Commonly used drugs are
⦁ Polyenes
Damage cell membrane of susceptible fungi E.g. Amphotericin B, Natamycin, nystatin
Side effect: nephrotoxicity
⦁ Imidazoles
Increase fungal cell membrane permeability
E.g. Miconazole, ketoconazole,fluconazole
⦁ Flucytocine
⦁ Act by inhibiting DNA synthesis
⦁ Dilate the pupil, ciliary muscle paralysis.
MYDYRIATICS AND CYCLOPLEGICS
Dilate the pupil, ciliary muscle paralysis
Classification
⦁ Short acting‐ Tropicamide (4‐6 hours)
⦁ Intermediate‐ Homatropine ( 24 hours)
⦁ Long acting‐ Atropine (2 weeks)
Indications
1. Corneal ulcer
2. Uveitis
3. Cycloplegic refraction
Directly acting agonists:
⦁ E.g. pilocarpine, acetylcholine (miochol), carbachol (miostat)
⦁ Uses: miosis, glaucoma
Mechanisms:
⦁ Miosis by contraction of the iris sphincter muscle
⦁ Increases aqueous outflow through the trabecular meshwork by longitudinal ciliary muscle contraction
⦁ Accommodation by circular ciliary muscle contraction
Side effects:
⦁ Local: diminished vision (myopia), headache, cataract, miotic cysts, and rarely retinal detachment
⦁ Systemic side effects: lacrimation, salivation, perspiration, bronchial spasm, urinary urgency, nausea, vomiting, and diarrhea
⦁ Indirectly acting: (anticholinesterases)
⦁ More potent with longer duration of action
⦁ Reversible inhibitors
E.g. Physostigmine
⦁ Used in glaucoma and lice infestation of lashes
⦁ Can cause CNS side effects
ANTIGLAUCOMA DRUGS
Mechanisms of action of antiglaucoma agents
The antiglaucoma agents act on the aqueous humor dynamics to reduce the intraocular pressure mainly by three mechanisms.
1. Decrease aqueous production in the ciliary body
2. Increase aqueous humor outflow through the trabecular meshwork
3. Increase aqueous humor outflow via the uveoscleral pathway.
Pharmacotherapy of Glaucoma
Prevention or modification of risk factors, particularly the raised intraocular pressure is the primary goal in the management of glaucoma. The disease needs to be managed medically, by laser therapy or by conventional
surgery as the case may be.
Classification of antiglaucoma agents
Depending on their route of administration antiglaucoma agents may be classified as
Topical drugs:
1. Cholinergic agents e.g. pilocarpine, carbachol,demecarium bromide and echothiophate iodide.
2. Adrenergic agonists e.g. epinephrine, dipivefrin,brimonidine and apraclonidine.
3. Beta blockers e.g. timolol, carteolol, betaxolol,levobunolol and metoprolol
4. Prostaglandin analogs e.g. PGF2α, latanoprost,
unoprostone and PHXA-85.
5. Carbonic anhydrase inhibitors e.g. dorzolamide
and brinzolamide.
Systemic drugs:
1. Carbonic anhydrase inhibitors e.g. acetazolamide and methazolamide.
2. Osmotic agents e.g. glycerine, mannitol and urea.
CORTICOSTEROIDS
Classification
1. Short acting
Hydrocortisone, cortisone, prednisolone
2. Intermediate acting
Triamcinolone, Fluprednisolone
3. Long acting
Dexamethasone ,betamethasone
INDICATIONS FOR CORTICOSTEROIDS
Topical
1. Allergic conjunctivitis,
2. Scleritis,
3. Uveitis,
4. allergic keratitis
5. After intraocular and extra ocular surgeries
Systemic (pathology behind the Lens)
1. Posterior uveitis
2. Optic neuritis
3. Corneal graft rejection
NEVER GIVE STEROID IFYOU ARE SUSPECTING ACTIVE INFECTION
SIDE EFFECTS OF CORTICOSTEROIDS
OCULAR
1. Glaucoma
2. Cataract
3. Activation of infection
4. Delayed wound healing
SYSTEMIC
1. Peptic ulcer
2. Hypertension
3. Increased blood sugar
4. Osteoporosis
5. Mental changes
6. Activation of tuberculosis and other infections
