This document discusses antibiotic ocular drugs, including their modes of administration, guidelines for effective use, reasons for treatment failure, and relationship to bacterial structure. It covers various classes of antibiotics like penicillins, cephalosporins, aminoglycosides, fluoroquinolones and their mechanisms of action, clinical uses, side effects and contraindications. The presentation provides an overview of antibiotic ocular drug therapy and factors influencing treatment effectiveness.

1. Antibiotic ocular drugs
Presenter : Surendra Prasad Sah
M.Optom
(13/10/2014)

2. Modes of administration
 Topical instillation into the conjunctival sac
Intraocular penetration of topically instilled
drugs
Intraocular injections
Systemic administration

3. 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

4. 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

5. Reasons for antimicrobial
failure
 Inaccurate diagnosis
 Resistant microorganism
 Inadequate drug dosage
 Inadequate supplemental physical procedures
 Inadequate patient immune system response
 Patient noncompliance

6. Microorganisms resistance
Producing 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

7. 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

8. 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

9. Relationship between bacterial
structure and antibacterial drug action

10. Drugs affecting cell wall synthesis
Include :-
Penicillin
Cephalosporins
 bacitracin
Vancomycin

11. 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

12. Commonly used penicillins
 Benzyl penicillin
 Procaine penicillin
 Methicillin ,cloxacillin and flucloxacillin
 Carbenicillin
 Ampicillin
 Amoxycillin

13. 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

14. 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

15. 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

16. 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

17. Side effects
Decreased renal function
Unusual serum sickness
Breast cancer developed
Vitamin k deficiency may developed

18. 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.

19. 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

20. Drugs affecting the cell membrane
Include :-
Polymyxin B
Gramicidin

21. 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 .

22. Clinical uses
Treat skin infections and external otitis
Treat infection of lids and conjunctiva
To prevent infection when conjunctiva or
cornea is compromised

23. Side effects
Irritation and allergic reactions of the eyelids
and conjunctiva
Causes pain, chemosis and tissue necrosis
when administered by subconjunctival
injection

24. Drugs affecting protein synthesis
Include:-
 Aminoglycosides
 Tetracyclines

 Macrolides
 chloramphenicol

25. Aminoglycoside
Inhibit bacterial protein synthesis by binding to 30s
subunit of the bacterial ribosome
Include:-
 Gentamicin
 Tobramycin
 Neomycin
 amikacin

26. 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

27. Conti……….
Tobramycin:-
 Treatment of corneal ulcer
Amikacin:-
 Treatment of gram-negative bacillary infections
 Treatment of bacterial endophthalmitis

28. 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

29. 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

30. 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 ’

31. 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

32. 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

33. 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

34. 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

35. 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

36. 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

37. 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

38. 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

39. 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

40. 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

41. 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

42. Discussion
Thank you