Anti-Infectives Flashcards
1
Q
Types of Antibacterial Drug
A
- Aminoglycosides
- Cephalosporin
- Macrolides
- Quinolones
- Chloramphenicol
- Fusidic Acid
2
Q
Aminoglycosides
A
- Mechanism
- Interfere with ribosome function affecting protein synthesis, producing an abnormal codon
- Bacteriocidal
- Indications
- Broad indications against bacterial eye infections
- Better against gram negative
- Examples
- Gentamicin (0.3% generic)
- Neomycin (less suitable for prescribing)
- Tobramycin (not available)
3
Q
Gentamicin
A
- Aminoglycoside
- Toxic to ocular surface (usually not severe)
- Cautions
- Nephrotoxicity
- Ototoxicity
- Neuromuscular blocking effects
- Contraindications
- Allergy
- Myasthenia gravis
- Undesirable Effects
- Local sensitivity
- Blurred vision
- Eye irritation
- Burning/stinging/itching
- Pregnancy & Breastfeeding
- Only in life threatening situations in pregnancy
- Relatively safe in breastfeeding
4
Q
Cephalosporins
A
- Mechanism
- Interferes with cell wall synthesis
- Bacteriostatic
- Indications
- Prophylaxis for endophthalmitis after cataract surgery
- Examples
- Cefuroxime
5
Q
Cefuroxime
A
- Cephalosporin
- Cautions
- Complicated surgery
- Reduced endothelial cell count
- Severe TED
- Interactions
- Can damage kidneys when combined with
- Aminoglycosides
- Aciclovir
- Gancicolvir
- Ketorolac
- Can damage kidneys when combined with
- Pregnancy & Breastfeeding
- Safe in both
6
Q
Macrolides
A
- Mechanism
- Inhibits translocations during protein synthesis taking place at ribosomes
- Bacteriostatic
- Indications
- Chlamydia trachomatis
- Stubborn blepharitis (off license)
- Bacterial conjunctivitis
- Useful against gram positive bacteria
7
Q
Azithromycin
A
- Cautions
- Treatment should cease after 3 days regardless of if symptoms remain
- Contraindications
- Hypersensitivity
- Undesirable Effects
- Eye discomfort
- Blurred vision
- Eye allergy
- Angioedema
- Pregnancy & Breastfeeding
- Safe for both
8
Q
Quinolones
A
- Mechanism
- Interferes with DNA gyrase to inhibit protein metabolism
- Bacteriostatic
- Medicinal Forms
- Ciprofloxacin
- Levofloxacin
- Moxifloxacin
- Ofloxacin
- Indications
- Eye infections (and corneal ulcers in the case of Ciprofloxacin)
9
Q
Ofloxacin
A
- Cautions
- Safety and effectiveness in those below 1 year is unknown
- Risk of corneal perforation in those with corneal defects
- Caution in those with risk factors for longer QT interval
- Interactions
- Anti-arrhythmics
- Tricyclic antidepressants
- Macrolides
- Antipsychotics
- Contraindications
- Allergy
- Undesirable Effects
- Ocular Irritation/Discomfort
- Ventricular arrhythmia
- Pregnancy and Breastfeeding
- Not suitable for either
10
Q
Chloramphenicol Mechanism
A
- Inhibition of protein synthesis by interaction with bacterial ribosomes
- Bacteriostatic
11
Q
Chloramphenicol Preparations & Dosage
A
- 0.5% Drops
- 1 drop in infected eye every 2 hrs for 48 hrs
- After this should be 4x a day during waking hours
- Course of treatmenr should last 5 days
- 1% Ointment
- Small amount 4x daily for 2 days
- Then 2x daily for 5 days
12
Q
Chloramphenicol Indications and Restrictions
A
- Indicated for superficial eye infections
- Potent broad spectrum
- Cost effective
- Can be used from age 2 when supplied directly by entry-level optometrist and can write a written order in patients from age 1 month
- Is available as branded eye drops (P Meds) and can only be used in patients over 2 for 5 days to treat acute bacterial conjunctivitis
13
Q
Chloramphenicol Cautions & Limitations
A
- Cautions
- Small risk of aplastic anaemia
- Interactions
- Avoid in patients taking drugs likely to depress bone. marrow function
- Contraindications
- History of blood dycrasias (incl aplastic anaemia)
- Allergy
- Undesirable Effects
- Irritation/burning/stinging
- Dermatitis
- Pregnancy & Breastfeeding
- Not recommended in either
14
Q
Fusidic Acid Mechanism & Indications
A
- Inhibition of protein synthesis by inhibiting DNA translocation
- Is bacteriostatic
- Potent narrow spectrum antibiotic effective against gram positive bacterial
- Indicated for:
- Marginal keratitis
- Blepharitis
- Conjunctivitis
- Can be used in children of any age
15
Q
Fusidic Acid Preparations and Dosage
A
- Fusidic Acid 1% Viscous Eye Drops
- Apply 2x daily
- Treatment should be continued for at least 48 hrs after eye returns to normal
16
Q
Fusidic Acid Cautions & Limitations
A
- Cautions
- Not to be used with CL as can cause corneal scratches
- Contains BAK
- Don’t use with quinolone as they are antagonistic
- Contraindications
- Allergy
- Pregnancy & Breastfeeding
- Can be used in both
17
Q
Fusidic Acid Undesirable Effects
A
Common
- Blurred vision
- Burning/stinging
- Redness
Uncommon
- Hypersensitivity
- Eyelid oedema
- Lacrimation
- Skin rash
- Angioedema
18
Q
Diamides
A
- Mechanism
- Aromatic diamidine with anti-bacterial, anti-protozoal and anti-fungal properties
- Indications
- Topical treatment of minor eye infections e.g. conjunctivitis and blepharitis
- Active against gram-positive non-spore forming organisms
- Examples
- Dibrompropmidine 0.15%
- Propamidine Isethionate 0.1%
19
Q
Propramidine Isetionate Cautions & Limitations
A
Cautions
- If no significant improvement after 2 days, discontinue and consult a physician
- Unsuitable for use with CLs
- Discontinue if vision becomes worse
Contraindications
- Allergy
Undesirable Effects
- Eye discomfort
- Blurred vision
Pregnancy & Breastfeeding
- Not suitable for either
20
Q
Topical Antivirals
A
- Active against HSV
- Blocks ability to replicate DNA
- Medicinal Forms
- Ganciclovir 0.15%
- Aciclovir 3%
21
Q
Ganciclovir
A
- Used for HSK
- Cannot be used in under 18s, whereas Aciclovir can
- Cautions
- Stinging on instillation
- Avoid CL wear
- Interactions
- Avoid use with other drugs which are likely to depress bone marrow function
- Contraindications
- Allergy
- Myelosuppression on previous exposure to chloramphenicol
- History of blood dycrasias (incl aplastic anaemia)
