antibiotic drug for eye diseases

Antibiotic ocular drugs

Presenter : Surendra Prasad SahM.Optom

(13/10/2014)

Modes of administration Topical instillation into the conjunctival sac

Intraocular penetration of topically instilled drugs

Intraocular injections

Systemic administration

Guidelines for effective antimicrobial therapy

Select anti-infective drug to which the microorganism is sensitive

Establish accurate clinical and laboratory diagnosis

Select least toxic anti-infective drug

Establish adequate drug levels at site of infection

Conti…………. Select optimum routes of administration

Use appropriate dosage regimen

Prescribe drug for appropriate length of time

Augment drug therapy with physical procedures

Educate patient

Reasons for antimicrobial failure

Inaccurate diagnosis

Resistant microorganism

Inadequate drug dosage

Inadequate supplemental physical procedures

Inadequate patient immune system response

Patient noncompliance

Microorganisms resistanceProducing an enzyme capable of destroying or

inactivating the antibiotics

Altering the target site receptor for the antibiotics so as to reduce or block its binding

Preventing the entry of the antibiotics into bacterial cell or actively transporting the antibiotic out of the bacterial cell

Antimicrobial therapy

Action Bactericidal

Bacteriostatic

Work Disrupt the wall of cell

Alter cellular membranes or protein production

Disrupt synthesis of vital component s

Alter cellular DNA

What the patient needs to know Always follow doctors instruction when taking anti –invectives.

using drops more often than prescribed may cause a toxic reaction

Always finish the full course

Stomach upset is very common with oral antibiotic therapy

Never use non ophthalmic OTC antibiotics in the eye

Tetracycline products may increase your sensitivity to sun

Vigamox is naturally yellow coloured ,this does not means that drops have gone bad

Relationship between bacterial structure and antibacterial drug action

Drugs affecting cell wall synthesis

Include :-Penicillin

Cephalosporins

bacitracin

Vancomycin

Penicillins

All penicillins contain a common nucleus composed of a thiazolidine ring and beta –lactam ring connected to a side chain

The penicillins act by inhibiting synthesis of the bacterial cell wall

Bacteriocidal agents

Unstable in solution and penetrate the cornea poorly

Commonly used penicillins

Benzyl penicillin

Procaine penicillin

Methicillin ,cloxacillin and flucloxacillin

Carbenicillin

Ampicillin

Amoxycillin

Clinical uses

Generally more effective against gram-positive organisms

Treatment of syphilis and syphilitic eye disease(stromal inflammation and vascularisation ,episcleritis ,scleritis ,papillitis ,retinal vasculitis ,exudative retinal detachment)

To treat respiratory infections in children

Mild preseptal cellulitis

Treated before nasolacrimal duct irrigation ,probing or surgery is performed

Side effects Hyper-sensitivity responses

Pain and tenderness at the site of an intramuscular injection

Central nervous system include headache,dizziness,confusion

May experience nausea,vomitting or diarrhea

Cause oral contraceptive to fail

Breast cancer may developed

Cephalosporins

First –generation:-

Include:- cephradine , cephalexin ,cefadroxil ,cefazolin

Uses:-all act effectively against gram –positive bacteria , corneal ulcers

Second –generation:-

Include:-cefaclor, cefuroxime ,cefoxitin , cefotetan

Uses:-mild preseptal cellulitis

Conti………

Third –generation :-

Include:- cefotaxime , cefixime , cefotetan

Uses:-endophthalmitis,preseptal cellulitis,gonococcal ophthalmia neonatorum

Fourth –generation:-

Include:-cefepime

Uses :-activity for both gram- negative and positive organisms

Side effects

Decreased renal function

Unusual serum sickness

Breast cancer developed

Vitamin k deficiency may developed

Bacitracin

Inhibits bacterial cell wall synthesis by inhibition the movement of a precursor of peptidoglycan though the cell membrane from the cytoplasm to the cell wall.

Clinical uses

To treat skin and mucous membrane

Mostly against gram –positive bacteria

Treat minor skin cuts and abrasions

Superficial eye infections

Treating staphylococcal blepharitis

Drugs affecting the cell membrane

Include :-

Polymyxin B

Gramicidin

Polymyxin B

• A cationic detergent or surfactant that interacts with the phospholipids of cell membrane ,thus disrupting the osmotic in integrity of cell.

• This increases the bacterial cell’s permeability and causes cell death .

Clinical uses

Treat skin infections and external otitis

Treat infection of lids and conjunctiva

To prevent infection when conjunctiva or cornea is compromised

Side effects

Irritation and allergic reactions of the eyelids and conjunctiva

Causes pain, chemosis and tissue necrosis when administered by subconjunctival injection

Drugs affecting protein synthesis

Include:-

Aminoglycosides

Tetracyclines

Macrolides

chloramphenicol

Aminoglycoside Inhibit bacterial protein synthesis by binding to 30s

subunit of the bacterial ribosome

Include:- Gentamicin

Tobramycin

Neomycin

amikacin

Clinical uses

Neomycin :- To treat a variety of skin and mucous membrane infections

Active against most gram –negative bacilli and some gram-positive cocci

Gentamicin:- To a variety of bacterial infections of the external eye and

conjunctivitis, blepharitis and kerato-conjunctivitis

Initial treatment of bacterial corneal ulcers

Conti……….

Tobramycin:- Treatment of corneal ulcer

Amikacin:- Treatment of gram-negative bacillary infections

Treatment of bacterial endophthalmitis

Side effects

Neurotoxicity manifest as auditory and vestibular ototoxicity occurs

Nephrotoxicity

Corneal toxicity –punctate epithelial erosions ,delayed reepithelization and corneal ulceration

Conjunctival toxicity –chemosis, hyperemia and necrosis

Tetracyclines

These are broad-spectrum bacteriostatic agents with a considerable action against both gram-positive and gram – negative organisms as well as some fungi .

Includes tetracycline , chlortetracycline and oxytetracycline

Clinical uses

In adults with chlamydial ocular infection such as inclusion conjunctivitis or trachoma

Not cause chemical conjunctivitis typically produced by silver nitrate

Effective therapy for noninfectious condition eye such as acne rosacea or meibomianitis

Effective for resolving noninfective corneal ulcers or ‘corneal melting ’

Side effects

Heartburn , nausea , vomiting ,diarrhea commonly occurs

Cause azotemia in patients with impaired renal function

Bone growth depression and tooth discoloration

Lightheadedness , loss of balance ,dizziness, nausea beginning 2 to 3 days

chloramphenicol

clinical uses:- Active against most gram-positive and gram-negative bacteria

Effective against most bacterial infections of the external

Side effects:- Dose-related toxic effect cause a bone marrow depression

Bone marrows depression consists of aplastic anemia

Drugs affecting folate metabolism

Include :-

Sulfonamides :-act by inhibiting bacterial synthesis of folic acid ,a chemical required for synthesis of nucleic acid and protein

Pyrimethamine and Trimethoprim :-reversibly inhibit in the synthesis of folic acid by inhibiting the enzyme dihydrofolate reductase ,which catalyzes the reduction of dihydrofolic acid to tetrahydrofolic

Clinical uses

Treatment for acute uncomplicated urinary tract infection

Treatment the protozoan disease toxoplasmic retinochoroiditis

Treatment of blepharitis and conjunctivitis

Treatment of blepharoconjunctivitis

Treatment of bacterial pediatric infection

Side effects Gastrointestinal disturbances including nausea ,vomiting and diarrhea

Allergic skin reactions such as rash and urticaria and more severe Stevens –johnson syndrome can occur

Cause blood dyscrasias

myopia ,with or without induced astigmatism has been reported

Photosensitization which can result in sunburn on lid margins or skin of face

Patients experience a hypersensitivity reaction consisting of lid edema ,itching, increased redness, tearing or periocular rash

contraindications

Patients with known hypersensitivity or intolerance to any member of this drug family

Pregnancy at term ,for nursing mothers and for infants less than 2 months

Patients with documented blood dyscrasias

Patient taking oral hypoglycemic dugs

Drugs affecting bacterial DNA synthesis

Drugs that inhibit bacterial DNA synthesis include fluorinated quinolones (fluoroquinolones ),which are structurally related to nalidixic:

Lomefloxacin

Norfloxacin

Enoxacin

Ciprofloxacin

Sparfloxacin

Germifloxacin

Levofloxacin

gatifloxacin

moxifloxacin

Clinical uses

Extremely effective bacteriocidal drugs and against gram-negative

Only ciprofloxacin and ofloxacin are approved by FDA for treatment of corneal ulcers

Treatment of complicated urinary tract infections and prosatitis and sinusitis

Treatment of bacterial conjunctivitis

Treatment of more serious infection and bacterial karatitis

Side effects

Gastrointestinal , dermatologic ,central nervous system reaction and photo toxicity

Local burning or discomfort ,bitter taste after instillation ,white precipitates ,FB sensation, itching and conjunctiva hyperemia , chemosis and photophobia

Treatment of corneal ulceration can result in white precipitates

contraindications

Patients with a history of hypersensitivity to any drug in family

Caution in patient with central nervous system disorders

Not recommended for systemic administration in children ,adolescents younger than age 18 years or pregnant women

References

clinical ocular pharmacology Jimmy D.bartlett

Siret D. jaanus

Modern pharmacology with clinical application

Charles R.craig

Robert E.stitzel

Ophthalmology A.K.khurana

Discussion

Thank you