Antibiotics Flashcards
Most common cause of conjunctivitis
Viral
Sabouraud’s
Culture media for fungi
Which antibiotics target bacterial cell wall?
Beta-lactam: PCN, cephalosporins
Vancomycin: gram+
Penicillin-sensitive PCN
Amoxicillin
Which antibiotic is used for PCN-resistant staph?
Dicloxacillin
Augmentin
Amoxicillin + clavulanic acid
Clavulanate
Beta-lactamase inhibitor - reduces bacteria’s ability to negate effect of amoxicillin (PCN-sensitive) by inactivating penicillanases
Which antibiotic is effective for skin infections (dacryocystitis, internal hordeola, pre-septal cellulitis)?
Augmentin
Which type of pts are more prone to side effect of PCN
Sick pts w/ heart problems
Internal hordeola is secondary to
Staph infection of meib glands
Cephalosporins break down
Gram- and anaerobes
Bactericidal
Which antibiotic has cross-sensitivity w/ PCN?
Cephalosporin (beta-lactams)
Person who has a reaction to PCN will probably have a reaction to cephalosporin too. (Cephalosporin more resistant to B-lactamases tho)
Which antibiotic is used to treat dacryadenitis?
Cephalexin
Hyperacute conjunctivitis
Secondary to gonorrhea
Tx: ceftrixone or cefixime (third generation cephalosporins)
Tetracycline is bactericidal. True or false?
False
Low dose ___ effectively used to tx acne
Tetracycline
Side effects of tetracycline
Pseudotumor cerebri (benign intracranial HTN)
Vestibular problems — esp Minocycline
Photoxicity
Effects on teeth and bones
Reduces effectiveness of BC — EXCEPT doxy and minocycline
Do not use w/ mild products.
Tetracycline suppress inflammation by inhibiting
PLA2
Corticosteroids also inhibit PLA2.
S/S of acne rosacea
Red, irritated eyes
Swollen eyelids
What looks like a stye
Secondary ocular complications in 85% of pts w/ acne rosacea. Ocular complications precede other skin manifestations.
Tx for acne rosacea
Oracea (Doxy 30mg or 10g delayed release) po
Tetracycline
Tx for recurrent corneal erosions
Doxy and topical steroids
Macrolides are bacteriostatic. True or false?
True
Macrolides are used to tx
Soft tissue infections, skin infections, respiratory/GI tract
Group of antibiotics used for those allergic to PCN
Macrolides
Tx for bacterial conjunctivitis
Azasite (Macrolides) - Azithromycin gtts
Erythromycin has a high incidence of staph resistance. True or false?
True
Preferred therapy for urethritis by chlamydia
Azithromycin
Azithromycin is contraindication in pregnant women. True or false?
False
Use Azithromycin w/ caution in pts w/
Liver disease
Adult inclusion conjunctivitis
Mixed papillary/follicular conjunctivitis on upper lid in sexually active adults
Tx for chlamydia
Azithromycin
Aminoglycosides are bactericidal. True or false?
True
Works against gram- bacilli
This antibiotic can cause nephrotoxicity and too toxicity.
Aminoglycosides
This antibiotic is used treat methicillin-resistant S.aureus (gram+) and MRSA.
Vancomycin
Poor oral absorption - admin systemically
Bactericidal
Adverse effect of Vancomycin
Red man syndrome
Most potent anti tuberculosis drug
Isoniazide
Also used w/ rifampin
Bacitracin is used as a systemic med. True or false?
False
Gram+
Fluoroquinolones are bactericidal. True or false?
True
Interferes w/ action of DNA gyrase and topoisomerase IV
Can cause tendon ruptures
Fluoroquinolones
Contraindicated in pregnancy, nursing mothers, children under 18
Category C drug - can cause seizures, increased hr, confusion
Parinaud’s (Cat-Scratch dx)
Infection w/ Bartonella
Granulomatous conjunctivitis w/ asso preauricular lymphadenopathy
Commonly used to tx bacterial conjunctivitis and keratitis (standard tx for bacterial keratitis)
Ocular fluoroquinolones (FDA approved: Ciloxxan, Ocuflox, Iquix)
Inhibitors of metabolism
Sulfonamides and trimethoprim - folic acid antagonists (bx cannot divide w/o folic acid)
Sulfonamides are bacteriostatic and used to treat UTIs. True or false?
True
Trimethoprim can be used to treat UTIs and MRSA. True or false?
True
Antibiotic used to treat pseudomonas (most common ocular pathogen); excellent for bacterial conjunctivitis in children; also used to treat haemophilus influenza and streptococcus pneumoniae
Polytrim (Polymyxin B)
gram- bactericidal
Antibiotic used to treat toxoplasmosis chorioretinitis
Pyrimethamine
Bactericidal used systemically (rarely used for ocular conditions) that can cause gray-baby syndrome
Rifampin
Other adverse effects: hemolytic and aplastic anemia, optic neuritis
Which antibiotics can cause nephrotoxicity?
Aminoglycosides, tetracycline, vancomycin
Which antibiotics reduce bactericidal action of PCN?
Tetracyclines and chloramphenicol
Which antibiotics decrease effectiveness of oral contraceptive?
PCN, ampicillin, tetracycline, cephalosporin
Which antibiotics are considered safe for children?
PCN, cephalosporin, erythromycin, azithromycin, biaxin
Which antibiotics should we consider if pts are allergic to PCN?
Oral fluoroquinolones (Levofloxincin 500mg qd x1 week, 1-2 DS bid x 1 week)
What is the drug of choice for MRSA?
Trimethoprim/sulfamethoxazole
What should we use for pts allergic to sulfa?
Doxy at its acute therapeutic dosage of 100mg bid x7-10 days
Oral drugs for acute care
Acute internal hordeola
Chlamydial conjunctivitis - Azithromycin
Allergy to PCN - Erythromycin (Macrolides) or fluoroquinolones
Allergy to sulfa - Doxy
Metronidazole can cause ____ failure during pregnancy.
Hepatic
