26 + 27: Antibiotics Flashcards
5 MOAs of antibiotics
- inhibit cell wall synthesis
- alteration of membrane permeability
- inhibition of protein synthesis
- inhibition of synthesis of bacterial RNA and DNA
- interference w/ cellular metabolism
3 types of abx combo effects
- additive (effect is doubled)
- potentiative (multiplied effects)
- antagonistic (if one is bacericidal and one is bacteriostatic)
general adverse reactions to abx
- allergic reactions
- superinfection
- organ toxicity: ear, liver, kidney
structure of beta-lactam abx
name derived from beta-lactam ring -> essential for antibacterial activity (cell wall lysis)
how is resistance developed against beta-lactam abx
specific enzymes can disrupt ring and inactivate MOA (beta-lactamase enzyme produced by bacteria -> resistance)
examples of beta-lactam abx
- penicillins
- cephalosporins
- carbapenems
- monobactams
MOA of penicillins
- inhibit bacterial cell wall synthesis (beta-lactam structure)
- bacteriostatic and bactericidal effects depending on drug dose
types of penicillins
- basic
- broad-spectrum
- penicillinase-resistant
- extended-spectrum
uses of basic penicillins
narrow spectrum
- gram (+) and a few gram (-) bacteria
- streptococcus and Clostridium species
- Neisseria and staphylococcus species
- treats anthrax, tetanus, diphtheria, endocarditis, respiratory infections, and syphilis (injectable)
example of a broad-spectrum penicillin
Amoxicillin
uses of amoxicillin
treat bacterial infections caused by variety of different bacteria (broad spectrum)
side effects/adverse effects of amoxicillin
- hypersensitivity
- anaphylaxis
- superinfection (ex. yeast infections)
- tongue discoloration and stomatitis
- GI distress
- C diff associated diarrhea
black box warning for penicillin G (broad-spectrum penicillin)
inadvertent IV administration of penicillin G benzathine can cause cardiopulmonary arrest and death
MOA of beta-lactamase inhibitors
inhibit bacterial beta-lactamases extending antimicrobial spectrum
what are beta-lactamase inhibitors combined with
- penicillinase-sensitive penicillin
- piperacillin tazobactam, ampicillin sulbactam (parentral), amoxicillin clavulanate (oral)
characteristics of cephalosporins
- beta-lactam structure
- derived from fungus
- 5 groups (first, second, third, fourth, and fifth generation)
uses of cephalosporins
- broad-spectrum antibiotic w/ activity against gram (+) and gram (-) bacteria
- more activity against gram (-) compared w/ penicillins
describe 1st generation cephalosporins
effective against most gram (+) and some gram (-) bacteria
bacteria affected by 1st generation cephalosporins
- staphylococci
- streptococci
- E. coli
- Klebsiella
- Proteus
- Salmonella
- Shigella
describe 2nd generation cephalosporins
effective against gram (+) and gram (-) bacteria
bacteria affected by 2nd generation cephalosporins
- staphylococci, streptococci, E. coli, Klebsiella, Proteus, Salmonella, and Shigella (like 1st gen)
- Haemophilus influenza
- Enterobacter
- Neisseria gonorrhea
- Nesseria meningitis
example of 1st generation cephalosporin
cefalexin (useful for common skin infection and cellulitis; not effective against MRSA)
example of 2nd generation cephalosporin
Cefuroxime (useful for otitis media, sinus infection, and pneumonia)
describe 3rd generation cephalosporins
- effective against gram (+) and gram (-) bacteria
- has increased resistance to destruction by beta-lactamases
bacteria affected by 3rd generation cephalosporins
- staphylococci, streptococci, E. coli, Klebsiella, Proteus, Salmonella, and Shigella (like 1st and 2nd gen)
- Haemophilus influenza, Enterobacter, Neisseria gonorrhea, and Nesseria meningitis (like 2nd gen)
- Pseudomonas aeruginosa
- Serratia and Acinetobacter
example of 3rd generation cephalosporin
Cefdinir (useful for otitis media, tonsillitis, and sinusitis); used a lot in children (causes red stools that are harmless)
describe 4th generation cephalosporins
- effective against gram (+) and gram (-) bacteria
- highly resistant to destruction by beta-lactamases
bacteria affected by 4th generation cephalosporins
staphylococci, streptococci, E. coli, Klebsiella, Proteus, and psuedomonas aeruginosa
describe 5th generation cephalosporins
- effective against gram (+) and gram (-) bacteria
- highly resistant to destruction by beta-lactamases
bacteria affected by 5th generation cephalosporins
- staphylococci, streptococci, E. coli, Klebsiella, Proteus, and psuedomonas aeruginosa
- MRSA
example of 4th generation cephalosporins
Cefepime (IV for bacteremia, respiratory and skin infections)
example of 5th generation cephalosporins
Ceftaroline (IV for skin and respiratory infections)
what type of drug is Ceftriaxone
3rd generation cephalosporin
MOA of Ceftriaxone
inhibit bacterial cell-wall synthesis (bactericidal) -> beta-lactam
uses for Ceftriaxone
respiratory, urinary, skin, bone, joint, and genital infections (more severe infections)
side effects/adverse effects to Ceftriaxone
- anaphylaxis
- superinfection
- headache, dysgeusia (altered taste), GI distress
- C diff associated diarrhea
- increased bleeding and seizures
- nephrotoxicity
- SJS
- elevated hepatic enzymes
Can cephalosporins be given to patients w/ allergic reactions to penicillins
yes but about 8% have cross reaction to cephalosporins too
administration of Ceftriaxone
IM or IV (not PO)
drug interactions w/ cephalosporins
- alcohol: causes disulfiram-like reaction (N/V, flushing, dizzy, headache, and muscle cramps)
- uricosurics (decrease excretion)
T/F: you want to get bacterial cultures before starting abx
True
describe macrolide abx
- bacteriostatic or bactericidal dependent on drug concentration in infected tissues
- effective against gram (+) cocci
what type of drug is Azithromycin
macrolide
MOA of Azithromycin (Z-Pak)
inhibits steps of protein synthesis (binds to 50S ribosomal subunit and inhibits protein synthesis)
uses of Azithromycin
- mild to moderate respiratory
- sinuses
- soft tissue/skin
- GI tract infections
- STIs
- conjunctivitis
- otitis media
side effects/adverse effects of Azithromycin
- anaphylaxis
- superinfection
- tinnitus and ototoxicity
- headache and seizures
- dysgeusia, tooth discoloration, and GI distress
- C diff associated diarrhea
- nephrotoxicity and hepatotoxicity
- SJS
drug interactions w/ macrolides
- levels of warfarin, theophylline and carbamazepine increase
- erythromycin levels increase w/ fluconozole, ketoconazole, itraconozole, verapamil, diltiazem, and clarithromycin -> his fo sudden cardiac death
- Azithromycin levels can be reduced by antacids
what type of drug is Vancomycin
glycopeptide
MOA of Vancomycin
inhibits cell wall synthesis
administration of Vancomycin
parenteral or oral (to treat bacterial colitis)
uses for Vancomycin
- MRSA
- substitute for PCN allergy
- endocarditis
- gram (+) microorganisms
- respiratory, skin, and bone/joint infections
- bacteremia and septicemia
- C diff associated diarrhea
side effects/adverse effects of Vancomycin
- ototoxicity
- anaphylaxis
- superinfection
- red neck or red man syndrome
- disulfiram like reaction to alcohol
- GI distress and peripheral edema
- neprhotoxicity
- C diff associated diarrhea
- SJS
describe red man syndrome
- occurs when IV Vancomycin is given too rapidly
- severe hypotension
- red blotching of face, neck, chest, and extremities
describe tetracyclines
- effective against wide range of gram (+) and gram (-) microbes
- not usually drug of choice due to resistance and toxic effects
- Doxycycline excreted in urine and feces
- Minocycline eliminated by liver
what type of drug is Doxycycline
tetracycline
MOA of Doxycycline
inhibits protein synthesis by penetrating microbial cells
uses of Doxycycline
- used for PCN allergy
- acne
- anthrax and plague
- gingivitis
- cholera
- STIs
- skin, urinary, and respiratory infections
side effects/adverse effects of Doxycycline
- anaphylaxis
- superinfection
- photosensitivity and diplopia
- discoloration of permanent teeth (pregnant women and children - avoid)
- stomatitis, glossitis, and GI distress
- C diff associated diarrhea
- ototoxicity, hepatotoxicity, and nephrotoxicity
- pancytopenia and SJS
interactions w/ tetracyclines
- milk products
- antacids
- oral contraceptive
- penicillins
- aminoglycosides
what type of drug is trimethoprim-sulfamethaxazole (TMP-SMZ)
sulfonamide
MOA of trimethoprim-sulfamethaxazole (TMP-SMZ)
inhibits bacterial synthesis of protein and folic acid
uses of trimethoprim-sulfamethaxazole (TMP-SMZ)
- otitis media
- meningitis
- malaria
- respiratory and urinary infections (building resistance)
- MRSA skin infections
side effects/adverse effects of trimethoprim-sulfamethaxazole (TMP-SMZ)
- anaphylaxis
- photosensitivity
- GI distress and stomatitis
- insomnia and tinnitus
- crystalluria and renal failure
- blood dycrasias
- SJS
- C diff associated diarrhea
- hyperkalemia and Torsades de pointes
describe aminoglycosides
- widely used to treat serious gram (-) infections
- bactericidal
- poorly absorbed from GI (local effects only if PO)
- well absorbed IM or IV
describe fluoroquinolones
- synthesized through addition to quinolone structure (older drugs used for UTIs)
what type of drug is Gentamicin sulfate
aminoglycoside
MOA of Gentamicin
inhibit bacterial protein synthesis
uses of Gentamicin
- serious respiratory, skin, urinary, bone/joint, and intraabdominal infections
- plague
- bacteremia/septicemia
- endocarditis
- meningitis and hepatic encephalopathy
side effects/adverse effects of Gentamicin
- anaphylaxis
- superinfection
- seizure
- photosensitivity
- anemia
- stomatitis and GI distress
- otoxicity
- nephrotoxicity
- C diff associated diarrhea
- SJS
drug interactions w/ aminoglycosides
- increased action of warfarin
- penicillins decrease effects
- ethacrynic acid may lead to ototoxicity
describe fluroquinolones
- synthetic bactericidal active against gram (-) and gram (+)
- well absorbed when given orally (achieves therapeutic concentrations in most body fluids)
- metabolizes mainly in kidneys and to some extent in the liver
what type of drug is Levofloxacin
fluoroquinolone
MOA of Levofloxacin
interferes w/ enzyme DNA gyrase needed to synthesize bacterial DNA
uses of Levofloxacin
- anthrax
- skin, soft tissue, bone/joint, GYN, intraabdominal, urinary and respiratory infections
- use in uncomplicated UTI if no other tx options are available
- not first line of treatment due to broad spectrum (prefer more specific drug)
side effects/adverse effects of Levofloxacin
- anaphylaxis
- superinfection
- photosensitivity
- eye damage
- visual disturbances
- GI distress and dysgeusia
- tendinitis and tendon rupture
- C diff associated diarrhea
- SJS
examples of unclassified antibacterials
- Chloramphenicol
- Obitoxaximab
MOA of Chloramphenicol
inhibit bacterial protein synthesis, bacteriostatic
uses of Chloramphenicol
- effective against gram (+) and gram (-) bacteria
- serious infections: bacteremia/septicemia, meningitis, and typhoid fever
side effects/adverse effects of Chloramphenicol
- anaphylaxis
- headache
- optic neuritis
- nephritis
- glossitis/stomatitis
- GI distress
- neurotoxicity
- anemia
- pancytopenia
MOA of Obitoxaximab
inhibits binding of protective antigen of bacterial toxin to cellular receptors preventing lethal factors of anthrax from intracellular entry
uses of Obitoxaximab
treats anthrax
side effects/adverse effect of Obitoxaximab
- anaphylaxis
- cough and headache
- rash, pruritus and injection site reaction
MOA of nitroimidazoles
- disrupts DNA and protein synthesis in bacteria and protozoa
- effective against H pylori, Clostridium, Giardia, Gardnerella, Prevotella, Peptococcus, and trichomonad vaginalis protozoa
uses of nitroimidazoles
- C diff associated diarrhea
- amebiasis
- giardiasis
- trichomoniasis
- bacterial vaginosis
- acne
- meningitis
- GYN, skin, intraabdominal and respiratory infections
side effects/adverse effects of nitroimidazoles
- anaphylaxis
- superinfection
- headache, dizzy, insomnia, weakness
- dry mouth dysgeusia and GI distress
- tongue/tooth discoloration
- peripheral neuropathy and seizures
- disulfiram-like reaction
- SJS
example of nitroimidazoles
Metronidazole
etiology of TB
mycobacterium tuberculosis (acid-fast bacillus)
transmission of TB
person to person (airborne) by coughing, sneezing, and talking
patients at risk of TB
- immunocompromised
- living or working in high-risk residential settings
- injecting illegal drugs
- health care workers w/ high-risk patients
sxs of TB
- cough, fever, night sweats
- GI distress and weight loss
- positive acid-fast bacilli in sputum or bloody sputum
who is TB prophylaxis recommended for
- close contact w/ active TB
- HIV positive/immunocompromised
- conversion from negative to positive TB test
- latent TB infection
- injection drug users
- recent immigrant from high prevalence country
drugs used for TB infection
- isoniazid
- rifampin
- rifabutin
- rifapentine
- pyrazinamide
- ethambutol
describe the combo therapy for TB
- minimum 3-5 drugs
- initial phase lasts 2 months
- continuation phase is 4-7 months
- should see improvement of sxs in 2-3 weeks
what type of therapy is used for administration of TB meds
- directly observed therapy (DOT): HCP or other responsible adult observes injection of TB meds
- mandatory for intermittent dosing schedules
- mandatory for MDR-TB
side effects/adverse effects of TB meds
- headache, dizzy, confusion
- GI distress
- peripheral neuropathy
- ocular, otic, renal, and hepatic toxicity
- thrombocytopenia
- respiratory depression
side effect specific to Rifampin
turns body fluids orange (soft contact lens may be permanently discolored)
side effects of pyridoxine (vitamin B6)
- hyperglycemia
- hyperkalemia
- hypophosphatemia
- hypocalcemia
MOA of isoniazid (INH)
inhibits bacterial cell wall synthesis
administration of isoniazid (INH)
PO or IM
side effects/adverse effects of isoniazid (INH)
- dry mouth, GI distress, constipation
- blurred vision and photosensitivity
- tinnitus
- drowsy, dizzy, and peripheral neuropathy
- psychotic behavior, tremors, and seizures
- hyperglycemia
- hepatotoxicity
- thrombocytopenia and agranulocytosis
MOA of rifampin (Rifadin)
kills mycobacteria by inhibiting synthesis of RNA -> causes production of defective nonfunctional proteins
administration of rifampin
PO (good absorption)
- IV reaches peak serum concentration immediately
uses for rifampin
- TB
- prophylaxis for people exposed to meningococcal meningitis
- leprosy (unlabeled)
adverse effects of rifampin
- GI upset and skin rash
- hepatotoxicity
- ARF
- red-orange discoloration of urine, tears, sweat, and other body fluids (harmless
T/F: antibiotics are safe to take during pregnancy and breastfeeding
True
