Opthalmic drugs

Acetazolamide

By M. Younus, BVSc, MVSc, SKUAST-K

Acetazolamide( synthetic sulphonamide)

  • Diuretic (Carbonic Anhydrase Inhibitor).
  • Drug for treatment of glaucoma.

MOA:

  • Acetazolamide acts through a non-competitive, reversible inhibition of the enzyme, carbonic anhydrase.
  • The formation of hydrogen and bicarbonate ions from carbonic acid is decreased, limiting their availability for active transport into body secretions.

Effects:

  • Decreased formation of aqueous humour and reduction in intraocular pressure.
  • Increased renal tubular secretion of sodium, potassium and bicarbonate, leading to increased urine alkalinity and volume.

Side effects:

  • GI disturbances.
  • CNS depression.
  • Hematologic effects (eg, bone marrow depression),
  • Renal effects (eg, crystalluria, dysuria, renal colic, polyuria).
  • Hypokalaemia.
  • Hyperchloremia.
  • Hyperglycaemia.
  • Hyponatremia.
  • Hyperuricemia.
  • Hepatic insufficiency.
  • Dermatologic effects (eg, ra hush)
  • Hypersensitivity reactions.

Species:

  • Dog, Cat and Horse.

Dose:

  • 4 – 10 mg/kg PO every 8-12 hours or IV OD in dogs.
  • 6 – 8 mg/kg PO every 8-12 hours in cats.
  • 2 – 3 mg/kg PO every 8-12 hours in horses.
  • Give oral doses with food if GI upset occurs.

Indication:

  • Glaucoma (open angle glaucoma) in small animals.
  • Hyperkalemic periodic paralysis (HYPP) in horses.
  • As an adjunctive treatment for syringomyelia in dogs.

Contraindication:

  • Hepatic insufficiency, renal insufficiency, pulmonary insufficiency or adrenocortical insufficiency.
  • Hyponatremia.
  • Hypokalemia.
  • Hyperchloremic acidosis.
  • Nausea and vomiting.
  • Electrolyte imbalance.

Brands:

Available as human brands in India.

  • Acetamide 250mg tab ( Micro Lab India).

Composition: Each tab contains 250mg Acetazolamide.

  • Avva 250mg tab ( Intas India).

Composition: Each tab contains 250mg Acetazolamide.

  • Diamox 250mg tab ( wyeth India).

Composition: Each tab contains 250mg Acetazolamide.

  • Synomax 250 mg tab ( Syntho India).

Composition: Each tab contains 250mg Acetazolamide.

Brinzolamide

By M. Younus, BVSc, MVSc, SKUAST-K

Brinzolamide(Sulfonamide derivative).

  • Extra labal use in dogs and cats.

MOA:

  • Carbonic anhydrase acts as catalyst for reaction between CO2 and H2O that results in the formation of carbonic acid( H2CO3)in ciliary epithelium of eye. The carbonic acid dissociates into H+ ion and HCO3- ion.
  • The bicarbonate and sodium ions are actively transported into the anterior chamber, leading to passive movement of water.
  • This is the major pathway for aqueous humor production in eye
  • Brinzolamide inhibits carbonic anhydrase thus reduces production of aqueous humor.

Effects:

  • Reduction in intraocular pressure.

Side effects:

  • Blepharitis, conjunctivitis and Keratitis.

Species:

  • Dog , Cat and Horse.

Dose:

  • 1% Brinzolamide 1drop /eye 2-3 times a day lifelong.

Indication:

  • Glaucoma.

Contraindication:

  • Topical hypersensitivity.

Brands:

Available as Human brands:

  • Brinzox 5ml eye drops ( Ajanta India).

Composition: Each ml contains Brinzolamide 1% w/v.

  • Azopt 5ml eye drops ( Novartis India).

Composition: Each ml contains Brinzolamide 1% w/v.

  • Brinzagan 5ml eye drops ( Allergan India).

Composition: Each ml contains Brinzolamide 1% w/v.

  • Brinolar 5ml eye drops ( Sun Pharma India).

Composition: Each ml contains Brinzolamide 1% w/v.

Dorzolamide

By M. Younus, BVSc, MVSc, SKUAST-K

Dorzolamide ( Sulphonamide derivative).

  • Extra label drug for dogs and cats.

MOA:

  • Carbonic anhydrase acts as catalyst for reaction between CO2 and H2O that results in the formation of carbonic acid( H2CO3)in ciliary epithelium of eye.
  • The carbonic acid dissociates into H+ ion and HCO3- ion.
  • The bicarbonate and sodium ions are actively transported into the anterior chamber, leading to passive movement of water.
  • This is the major pathway for aqueous humour production in eye
  • Dorzolamide inhibits carbonic anhydrase thus reduces production of aqueous humour.

Effects:

  • Reduction in intraocular pressure.

Side effects:

  • Blepharitis, conjunctivitis and Keratitis .

Species:

  • Dog , Cat and Horse.

Dose:

  • 1% Dorzolamide 1drop /eye 2-3 times a day lifelong.

Indication:

  • Glaucoma.

Contraindication:

  • Topical hypersensitivity.

Brands:

  • Visio-G 5ml eye drops ( Sava Vet India).

Composition: Each ml contains Dorzolamide 2% w/v and Timolol Maleate 0.5% w/v.

  • Opthocare -XT 5ml eye drops ( Corise India).

Composition: Each ml contains Dorzolamide 2% w/v and Timolol Maleate 0.5% w/v.

  • Opthoraj-DT 5ml eye drops (Hatvet Pharma India).

Composition: Each ml contains Dorzolamide2% w/v and Timolol Maleate 0.5% w/v.

Methazolamide

By M. Younus, BVSc, MVSc, SKUAST-K

Methazolamide (methylated analog of acetazolamide ).

  • Potent inhibitor of carbonic anhydrase.
  • Used as off label’ or ‘extra label drug in pets.
  • Given orally.

MOA:

  • Carbonic anhydrase acts as catalyst for reaction between CO2 and H2O that results in the formation of carbonic acid( H2CO3)in ciliary epithelium of eye. The carbonic acid dissociates into H+ ion and HCO3- ion.
  • The bicarbonate and sodium ions are actively transported into the anterior chamber, leading to passive movement of water.
  • This is the major pathway for aqueous humor production in eye
  • Methazolamide inhibits carbonic anhydrase thus reduces production of aqueous humor.

Effects:

  • Reduction in intraocular pressure.
  • Diuresis.

Side effects:

  • GIT disturbances including vomiting.
  • Renal problems including diuresis and stone formation.
  • Electrolyte imbalance.
  • Hepatic problems.
  • Fatigue and muscle weakness.
  • Reduced blood cell count.

Species:

  • Dogs and Cats.

Dose:

  • 2-5 mg /kg PO TD in dogs.
  • 3-4mg/kg PO TD in cats.

Indication:

  • Open angle glaucoma.

Contraindication:

  • Hypersensitivity to drug.
  • Significant liver, kidney, or adrenal disease.
  • Pets that have electrolyte imbalances.
  • Severe obstructive lung disease.
  • Closed angle glaucoma.

Brands:

Available as human brands in India.

  • Methazolamide 25mg tab ( offered by GNH India)

Composition: Each tab contains 25mg Methazolamide.

  • Neptazane 50mg tab (offered by GNH India)

Composition: Each tab contains 25mg Methazolamide.

Carboxymethyl Cellulose

By M. Younus, BVSc, MVSc, SKUAST-K

Carboxymethyl Cellulose

  • Cellulose is polymer of glucopyranose monomers)
  • One hydroxyl group of each glucopyranose bonds with carboxymethyl group.
  • This results in the formation of carboxymethyl cellulose.

MOA:

  • Carboxymethyl cellulose binds to the surface of corneal epithelial cells via its glucopyranose subunits that binds to glucose receptors GLUT-1 1.
  • This binding stimulates corneal epithelial cell attachment, migration, and re-epithelialization of corneal wounds

Effects:

  • Stabilization of the natural tear film and maintenance of necessary lubrication.
  • Healing of corneal wound.

Side effects:

  • Eye irritation.
  • Eye itching.
  • Eye pain.
  • Visual disturbance.

Species:

  • Dogs and Cats.

Dose:

  • 1-2 drops ( 0.5%w/v Carboxymethyl cellulose) per eye BD or TD.

Indication:

  • Irritation & dryness of the eye.
  • Burning sensation.
  • Chronic conjunctival irritation.
  • Kerato Conjunctivitis Sicca – KCS.
  • Discomfort due to wind, sun, or pollution effect.

Contraindication:

  • Do not use in the dogs /cats below 12 months of age.
  • Stop using the drug if it causes constant irritation to eyes.

Brands:

  • Hatmoist 5ml/10ml eye drops ( Hatvet Pharma India).

Composition: 0.5%w/v Carboxymethyl cellulose.

  • Opthocare-Cool 10ml eye drops ( Corise India).

Composition: 0.5%w/v Carboxymethyl cellulose.

  • Caneye-wet 10ml eye drops ( Kaizen India).

Composition: 0.5%w/v Carboxymethyl cellulose.

  • Light sense cool 10ml eye drops ( Veko India).

Composition: 0.5%w/v Carboxymethyl cellulose.

Artificial Tear

By M. Younus, BVSc, MVSc, SKUAST-K

Artificial Tear( opthalmic lubricant).

  • Artificial tear consists of Polyvinyl alcohol, Povidone ( polyvinylpyrrolidone) and Chlorbutol.

MOA:

  • Polyvinyl alcohol present in artificial tear acts as nonionic surfactant. It acts stabilizing agent, lubricant and as an agent to increase viscosity so prolongs contact time of the active ingredient with the eye.
  • Povidone( polyvinylpyrrolidone)is an active ingredient in artificial tear. It acts as mucinomimetic and retains the tears on the cornea for long duration.

Effects:

  • Keeps eye ball moist and prevents dryness of eye.

Side effects:

  • Visual disturbance.
  • Cloudy vision.
  • Extreme redness of the corneal tissues.

Consult veterinarian if symptoms persist for long time.

Species:

  • Dogs and Cats.

Dose:

  • Place 1 or 2 drops in effected eye as often as needed for reducing dryness of eyes.

Indication:

  • Keratoconjunctivitis sicca.

Contraindication:

  • Hypersensitivity reaction.

Brands:

  • Naturalube 15ml bottle ( Cipla Inida).

Composition:

Each ml artificial tear contains:

Poly vinyl alcohol 14mg.

Povidone 6mg.

Chlorbutol 5mg.

  • Visio tears eye 15ml bottle (Savavet India).

Composition:

Each ml artificial tear contains:

Poly vinyl alcohol 14mg.

Povidone 6mg.

Chlorbutol 5mg.

Tacrolimus.

By M. Younus, BVSc, MVSc, SKUAST-K

Tacrolimus( Macrolide Lactone)

  • Immunosuppressant.
  • Antiallergic.
  • Used for atopic dermatitis and dry eye condition in dogs.

MOA:

  • Tacrolimus binds to FK506-binding proteins within T lymphocytes and inhibits Calcineurin thereby suppresses formation of T helper cells , interleukins and interferon Y.
  • Tacrolimus inhibits release of histamine from Mast cells.

Effects:

  • Immunosuppression.
  • Antiallergic.

Side effects:

  • Transient burning sensation .
  • Corneal infections, including bacterial keratitis , herpetic keratitis and a bacterial corneal ulcer.

Species :

  • Dog and Cat.

Dose:

  • As per label.

Indication:

  • Keratoconjunctivitis sicca
  • Atopic dermatitis.

Contraindication:

  • Not Known.

Brands:

  • Takfa Pet 0.02% W/V 50ml spray for atopic Dermatitis( Intas India).
  • Taclimus 0.1% W/W ointment for eye( Corise India).
  • Ichmune T 0.1% W/W ointment for atopic Dermatitis( Savavet India).

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Cyclosporine

By M. Younus, BVSc, MVSc, SKUAST-K

Cyclosporine (non-ribosomal peptide).

  • Calcineurin inhibitors,and immunosuppressant used in organ transplant.
  • Topically used in dry eye condition and atopic dermatitis.

MOA:

  • Topical cyclosporine helps dogs with KCS by increasing the production of natural tears and promoting the regeneration of lacrimal gland tissue. It also increases lymphocytic apoptosis and suppresses epithelial cell apoptosis.
  • Cyclosporine also restores conjunctival goblet-cell mucin production.

Effects:

  • Moisturizing and soothing the eye.
  • Promoting the regeneration of corneal cells for healing, and boosting the production of lysozyme and antibodies to control infections.

Side effects:

  • Ocular pain and ocular irritation.

Species:

  • Dog

Dose :

  • As per label of brand.

Indication:

  • KSC and Atopic dermatitis.

Contraindication:

  • Discontinue use if there is persistent pain and irritation.
  • Hypersensitivity.

Brands:

  • Opthocare 5ml Eye Drop(Corise India).

Cmposition: Cyclosporine 0.1%

  • Aposporin 3.5 gm ointment (Apothecary Pharmaceutical Pvt Ltd India).

Strength :2 mg/g

  • Visiocare 5g ointment ( Sava vet India)

Strength : 2 mg/g

Atropine 1% eye drops

By M. Younus, BVSc, MVSc, SKUAST-K

Atropine (a tropane alkaloid)

  • Muscarinic antagonist and anticholinergic drug.
  • Cycloplagic in nature.
  • Causes mydriasis.

MOA:

  • In the eye, atropine, which is an anticholinergic, stops the circular pupillary sphincter muscle from contracting. This allows the radial iris dilator muscle to contract and widen the pupil.
  • Atropine paralyzes the ciliary muscles, which can help relieve pain from iridocyclitis and treat malignant glaucoma associated with ciliary muscle blockade.

Effects:

  • Cycloplegia and pain relief.
  • Mydriasis.
  • Synechia formation is stoped.
  • Blood-aqueous barrier is stabilized thereby leakage of inflammatory debris into aqous chamber is prevented.

Side effects:

  • Can increase intraocular pressure.
  • Decreases tear production.

Species:

  • Dog Cat and horse.

Dose:

  • As per the brand label

Indication:

  • Uveitis.
  • Synechiae associated glaucoma.
  • Corneal ulcer.

Contraindications:

  • Primary glaucoma .
  • Hyperslivation .
  • Rapid heart rate.
  • Occasional vomiting

Brand :

Human brands:

  • Atropine 10 ml eye drops ( Jawa pharmaceuticals India). Strength: Atropine 1%w/v.
  • Atrapar 5ml eye drops ( Biomedica international India). Strength: Atropine 1%w/v.
  • Atrosulph 5ml Eye drops( Entod pharmaceuticals India). Strength: Atropine 1%w/v.
  • Opthopin 5 ml Eye drops(Optho Remedies India). Strength: Atropine 1%w/v.

Timolol

By M. Younus, BVSc, MVSc, SKUAST-K

Timolol

  • Beta Blocker
  • Used in ocular hypertension.

MOA

  • Timolol probably reduces the formation of aqueous humor in the ciliary body in the eye.

Effects:

  • Reduction in intraocular pressure.

Side effects:

  • Irritation and pain, eye redness, superficial punctate keratopathy, corneal numbness.

Drug combination:

  • Dorzolamide+ TimololBrezolamide+ Timolol
  • These combination have additive effects.

Species:

  • Dog

Dose:

  • As per brand label.

Indication:

  • Secondary glaucoma.

Contraindication:

  • Hypersensitivity to Betablockers.

Brands:

  • Opthocare-XT 5ml( Corise India).
  • Composition:Dorzolamide 2% and Timolol 0.5%

Pilocarpine

By M. Younus, BVSc, MVSc, SKUAST-K

Pilocarpine ( Cholinergic drug)

  • Extra label used in dogs.
  • Causes miosis.
  • Good for primary Glaucoma.

MOA:

  • Pilocarpine act through stimulation of Muscurnic receptors of smooth muscle of eye.
  • It also causes contraction of ciliary muscle opening trabicular mesh.
  • it also stimulates nerves for trear production.

Effects:

  • Miosis and reduction in IOP.

Side effects:

  • Vomiting, diarrhea, increased salivation, increased urination, and coughing.

Species:

  • Dog

Dose:

  • As per brand label.

Indication:

  • Primary Glaucoma.
  • KCS

Contraindication:

  • Hypersensitivty.

Brands:

Available as Human brand in India:

  • Pilocar 2% 5ml eye drops( FDC India).
  • Paricar 2% 5ml eye drops( Biomedica Inda).
  • Carpkap 2% 5ml eye drops(Iskon remedies Inda).

Betaxolol

By M. Younus, BVSc, MVSc, SKUAST-K

Betaxolol ( β1 selective)

  • For the treatment of primary Glaucoma.
  • For prevention of Glaucoma.

MOA:

  • Betaxolol is selectively blocks β1 receptors in ciliary muscles in eye.

Effects:

  • Reduction in IOP.

Side effects:

  • Eye irritation.
  • Burning sensation.
  • Tearing.

Species:

  • Dog

Dose:

  • As per brand label.

Indication:

  • Primary or open angle Glaucoma
  • Prophylaxis of Glaucoma.

Brands:

Human brands in India:

  • Betaxolol 0.5% 5ml solution ( Actiza India).
  • Optipress 5ml solution ( Cipla India).
  • Iobet 0.5% 5ml solution ( FDC India).
  • Bexol0.5% 5ml solution ( Jawa Pharmaceuticals India).

Levobunolol

By M. Younus, BVSc, MVSc, SKUAST-K

Levobunolol ( L-enantiomer of bunolol)

  • Non selective beta blocker
  • used for primary Glaucoma

MOA:

  • Levobunolol quickly penetrates the cornea and reaches the aqueous humour.
  • It is reduced to dihydrolevobunolol, which is equally active, in the eye’s tissues.
  • It blocks beta 2 receptors in ciliary body, thereby reduces aqueous humour production.

Effects:

  • Lowering of intra occular pressure.

Side effects :

  • Eye irritation , uveitis and corneal oedema

Drug combination :

  • Levobunolol combined with dorzolamide produces a stronger hypotensive effect.

Species:

  • Dog
  • Cat

Dose:

As per label

Indication :

  • Primary Glaucoma

Contraindication:

  • Should not be used in patients having heart problem.

Brands :

Available as Human brands in India:

  • Betagan 0.5% 5ml eye drops ( Allergan India).

Amikacin

By M. Younus, BVSc, MVSc, SKUAST-K

Amikacin ( Aminoglycoside)

  • Concentration dependent bactericidal activity .
  • Broad-spectrum antibiotic derived from kanamycin.

MOA:

  • Amikacin binds 30s ribosome of bacteria and inhibits protein synthesis. This leads to inhibition of cell wall synthesis and death of bacteria.

Effects:

  • Bactericidal action. Effective against G negative bacteria..

Side effects:

  • Eye irritation and eye pain.
  • Dilated pupil.

Drug combination:

  • Combination with other Penicillin drugs to increase antibacterial spectrum.

Species:

  • Cat and Dog

Dose:

  • Apply Amikacin 1% to each eye 2-3 times daily.

Indication:

  • Topical application for eye and ear infections.

Contraindication:

  • Hypersensitivity to drug.

Brands:

Human Brands available India:

  • Amisole 0.01% Amikacin 5ml eye drops.
  • Amicon 1% Amikacin 5ml eye drops( Indiana Opthalmics India).
  • Mikadrop1% Amikacin 5ml eye drops(Hindustan Life Sciences India) .
  • Aminogen1% Amikacin 5ml eye drops(Jawa Pharmaceuticals India) .

Moxifloxacin 0.5% eye drops

By M. Younus, BVSc, MVSc, SKUAST-K

Moxifloxacin

Key features:

  • Advanced 4th generation fluroquinolone acting against bacteria, mycoplasma, chlamydia, fungus and others.
  • The spectrum of activity includes gram-positive cocci and anaerobic bacteria that may be resistant to other quinolones.

MOA:

  • DNA gyrase(topoisomerase II) is responsible for replication, transcription and repair of bacterial DNA.
  • Topoisomerase IV is responsible for partitioning of the chromosomal DNA during bacterial cell division.
  • Moxifloxacin inhibits both topoisomerase II (DNA gyrase) and topoisomerase IV.

Effects:

  • Bactericidal action.

Side effects:

  • Dizziness and fainting.
  • Rapid heartbeat.
  • Diarrhea and swelling.

Species:

  • Dog, Cat, Horse and Cattle.

Indication:

  • Eye infections.

Dose:

  • 1drop containing Moxifloxacin HCl 0.5 % W/V per eye 4-5 times daily in dog and cat.
  • 2-3 drops Moxifloxacin HCl 0.5 % W/V per eye 4-5 times daily in cattle and horse.

Contraindication:

  • Hypersensitivity to drug.

Brands:

  • Eye-Moxin 5ml(Moxifloxacin HCl 0.5 % W/V) Eye Drops ( Welkine Life Care).
  • Opthacare M 5ml(Moxifloxacin HCl 0.5 % W/V) Eye Drops ( Hatvet India) .
  • Lightsense 5ml(Moxifloxacin HCl 0.5 % W/V + Ketorolac tromethamine 0.5 % W/V ) Eye Drops ( Veko India) .
  • Oothovet M 5ml(Moxifloxacin HCl 0.5 % W/V ) Eye Drops ( Oriheal India) .
  • Moxipet-K (Moxifloxacin HCl 0.5 % W/V + Ketorolac tromethamine 0.5 % W/V ) Eye Drops ( Ektek Pharma India) .

Neomycin 0.5% eye drops

By M. Younus, BVSc, MVSc, SKUAST-K

Key features:

  • Antibiotic consisting of 3 components, A, B and C.
  • Used in veterinary medicine as the sulphate salt.
  • Component B is the largest-component of commercial preparations of neomycin (over 90%).
  • Framycetin (also known as Soframycin) is largely component B.
  • Component A is present only in traces (less than 1%).
  • Bactericidal antibiotic.
  • Effective against both gram-positive and gram-negative bacteria, including Staphylococcus aureus.
  • No absorption on oral use or local use.

MOA:

  • Neomycin irreversibly binds to specific 30S-subunit proteins and 16S rRNA andinhibits decoding site in the vicinity of nucleotide 1400 in 16S rRNA of 30S subunit.
  • This causes problems with the initiation complex, leading to mistakes in reading mRNA. Incorrect amino acids may be added to the polypeptide, resulting in nonfunctional or toxic peptides, and polysomes may break up into nonfunctional monosomes.

Effects:

  • Inhibition of protein synthesis
  • Bactericidal effect in gut infection, udder infection, Eye infection, and skin infection.

Side-effects:

  • Eye allergy.
  • Irritation of the eyes.
  • Blurry vision or other vision issues.

Species:

  • Dog and Cat.

Indication:

  • Gastrointestinal infections .
  • Mastitis.
  • local use for eye and skin infections

Drug combinations:

  • Neomycine + Bacitracin and corticosteroid for local use .

Dose:

  • 1-2 drops per eye 3-4 times a day.

Contraindication:

  • Discontinue if there is hypersensitivity reaction.

Brands:

Human Brands:

  • Necron-D 5ml (Neomycin And Dexamethasone) Eye Drop (Omicron Pharma India).
  • Neowell-D 5ml (Neomycin And Dexamethasone) Eye Drop (Wellona Pharma India).
  • Neowell-D 3ml (Neomycin And Dexamethasone) Eye Drop (Wellona Pharma India).
  • Betinade-N 5ml (Betamethasone 0.1% + Neomycin 0.5% + Hydroxymethylcellulose 0.25%) eye drops ( J N Health care India).