Antibiotics their indications/ causative organism use/ MOA/ Drug class Flashcards
antibiotic used exacerbations of chronic bronchitis
ACT
Amoxicillin
Clarithomycin
Tetracycline
antibiotic used for Uncomplicated community-acquired pneumonia
Amoxicillin (Doxycycline or clarithromycin in penicillin allergic, add flucloxacillin if staphylococci suspected e.g. In influenza)
Pneumonia possibly caused by atypical pathogens
Clarithromycin
Hospital acquired pneumonia
Within 5 days of admission: co-amoxiclav or cefuroxime
More than 5 days after admission: piperacillin with tazobactam OR a broad-spectrum cephalosporin (e.g. ceftazidime) OR a quinolone (e.g. ciprofloxacin)
lower uti
Trimethoprim or nitrofurantoin. Alternative: amoxicillin or cephalosporin
acute pyelonephritis
broad spec cephalosporin- ceftriaxone or quinolone
acute prostatis
quinolone or trimethoprim
Impetigo
Topical hydrogen peroxide, oral flucloxacillin or erythromycin if widespread
cellulitis
Flucloxacillin (clarithromycin, erythromycin or doxycycline if penicillin-allergic)
Erysipelas
Flucloxacillin* (clarithromycin, erythromycin or doxycycline if penicillin-allergic)
Animal or human bite
Co-amoxiclav (doxycycline + metronidazole if penicillin-allergic)
throat infections
Phenoxymethylpenicillin (erythromycin alone if penicillin-allergic)
which Abx is used for pseudomonas aeruginosa
Gentamicin (aminoglycoside)
Which Abx should be used for streptococci
benzylpenicillin or phenoxypenicillin
Which Abx should be used for MRSA infections
Vancomycin
Which antibiotic should be used for anaerobic infections
Metronidazole
which abx should be used for staphylococci infections e.g impetigo, cellulitis, CAP
Flucloxacillin
What is the MOA and drug class of Clindamycin
It inhibits protein synthesis for Gram +ve bacteria and anaerobes. It is bacteriostatic and narrow spectrum
It is a Lincosamide
what is the MOA and drug class of Linezolid
It is an oxazolidinone and reversibly inhibits MAO
Inhibits protein synthesis. Only active against gram +ve bacteria e.g. MRSA and anaerobes (narrow-spectrum + bacteriostatic)
Alternative to Vancomycin in MRSA infection.
What is the MOA of Chloramphenicol and when is it used
Chloramphenicol is a potent broad spectrum Abx, it is bacteriostatic and inhibits protein synthesis.
reserved for life-threatening infections due to s/e
What is the MOA of metronidazole
Inhibits DNA synthesis of anaerobic bacteria and protozoa. It is bactericidal and narrow spectrum
What are the uses of metronidazole
bacterial vaginosis, dental infections, antibiotic related colitis- H.pylori, rosacea
Protozoal infections: vaginal trichomoniasis, giardiasis
What is the MOA of Nitrofuratoin
Nitrofurantoin is a narrow-spectrum Abx that is only active against urinary pathogens, it is bactericidal and damages bacterial DNA.
what does bactericidal mean
Kills the bacteria by inhibiting bacterial nucleic synthesis
What is the MOA and drug class of ciprofloxacin. name other drugs in this class and indication
Inhibit DNA synthesis- broad spec and bactericidal
levofloxacin used for UTI
Ciprofloxacin used for LRTI
moxifloxacin prolongs QT, hepatoxic
norfloxacin
Ofloxacin
nalidixic acid (1st gen used for uncomplicated UTI but avoid if eGFR is under 20
With what type causative organism should quinolones be avoided
MRSA
what is the mechanism of action of tetraCYCLINES, others in drug class and indications
Inhibit bacterial protein synthesis; binds to ribosomal 30S subunit
(Broad spectrum + bacteriostatic)
Uses: Lower RTIs, Acne, Rosacea, Malaria and Chlamydia.
Examples:
Demeclocyline
Doxycycline (used in Malaria and Chlamydia: OD)
Lymecycline
Minocycline (broader spectrum but rarely used)
Oxytetracycline
Tetracycline
Tigecycline (antibiotic structurally related to tetracycline)
what is the mechanism of action of aMINoglycosides, drugs in class and indications
Bind irreversibly to bacterial ribosomes. Active against gram -ve aerobe; pseudomonas aeruginosa. (Broad-spectrum + bactericidal)
Aminoglycosides are broad spectrum Abx, they work by binding irreversibly to bacterial ribosomes, and are bactericidal, although this effect is likely due to additional mechanisms that are not completely understood.Gentamicin (choice; active against pseudomonas aeruginosa)
Tobramycin (via inhaler for pseudomonal infection in cystic fibrosis)
Streptomycin (active against mycobacteria reserved for TB)
Neomycin (parenterally toxic. Use in bowel sterilisation)
Amikacin (gentamicin-resistant gram -ve bacilli)
Used in severe sepsis, pyelonephritis, endocarditis and UTI
which ABx’s are given as blind therapy in an undiagnosed serious infections
Gentamicin to cover gram -ve pseudomonas aeruginosa
metronidazole and penicillin to cover the anaerobes, haemolytic streptococci and pneumococci
what is the MOA, drugs in class and indcation of glycopeptides
Inhibits cell wall synthesis (by inhibiting the cross-linking of peptidoglycan chains in the cell wall) of aerobic and anaerobic gram +ve bacteria It is narrow spectrum
Vancomycin- active against MRSA
Teicoplanin
Telavancin only in HAP when other antibiotics are unsuitable
What are the indactions of Vancomycin
antibiotic associated colitis, MRSA
Given parenterally when a serious infection
What is MOA, drugs in class of Macrolides
Inhibits the bacterial protein synthesis by binding subunit 50S subunit of the ribosome- broad spectrum and bacteriostatic. Azithromycin Clarithromycin Erythromycin Telithromycin Spiramycin
what is the MOA and drug in class for penicillins
they are bactericidal- inhibit cell wall synthesis.
narrow spectrum are beta-lactamase sensitive e.g benzylpenicillin, phenoxymethylpenicillin
broad spectrum inactivated by beta-lactamases e.g amoxicillin, ampicillin, flucloxacillin, pipercillin, ticaricillin meaning it is active against beta-lactamases strains
Name the antipseudomonal penicillins and what their uses
Piperacillin and tazobactam- they are extended spectrum
ticaricillin and clavulanic acid
used for serious infections e.g septicaemia, complicated UTI, HAP
Effective against pseudomonas aeroginosa
tazobactam and clavulanic are beta lactamase inhibitors
what is the indication for benzylpenicillin (ben pen)
Meningitis - meningococcal infections
what is the indication for phenoxymethylpenicillin (pen V)
Usedf for streptococcal infections such as RTI in children such as tonsillitis or strep throat
Uses of flucloxacillin
it is penicillinase resistant so used for pen resistant staphylococcal infections except for MRSA
e.g Impetigo, cellulitis
why should penicillins not be given blindly for sore throats
causes maculopapular rash in glandular fever
what are the indications for ampicillin
highly resistant so consider before blindly prescribing
Uses: UTI’S, Otitis media, acuter COPD exacerbations
what type of strains of bacteria are amoxicillin active against
beta lactamase strains
What are tazobactam and clavulanic acid used as
tazobactam and clavulanic are beta lactamase inhibitors
what is the MOA and drugs in class of cephalosporins
Interefers with the bacterial wall synthesis - broad spectrum and bactericidal
Used for UTI (Pregnancy) sinusitis, otitis media
name the 1st gen cephalosporins ‘cefa’
Cefalexin
Cefadroxil
Cefadrine
name the 2nd gen cephalosporins ‘2 foxes for tea’
Cefuroxime
cefaclor- causes skin reactions in children
Name the 3rd gen cephalosporins and which two treat meningitis
Cefixime
Ceftriaxone- Treats meningitis
Cefotaxime- treats meningitis
Ceftazidime
name the 5th gen cephalosporins ans its indication
Ceftaroline
used in CAP and complicated skin/ soft tissue infections
Which antibiotics are used first and second line for c. diff infections
first episode of mild-moderate infection = oral vancomycin 125mg qds 10-14 days
Subsequent episodes/ severe episodes = Fidoxamicin
Which antibiotics are most likely to cause antibiotic- associated colitis (c.diff)
Clindamycin- the msot
Ampicillin/Amoxicillin
2nd/3rd gen cephalosporins
Quinolones
Which groups are most likely to get antibiotic associated colitis (c.diff)
Elderly, Women
What are the treatment options for endocarditis
Amoxicillin and add low dose gentamicin
if MRSA/ pen allergy use Vancomycin
If Staphylococcal use flucloxacillin
If streptococcus use benzylpenicillin
What is the treatment for CAP
Treatment for 7 days
mild severity- amoxicillin
Alternatively Clarithromycin or Doxycycline
Moderate severity: Amoxicillin and Clarithromycin
OR Doxycycline alone
High severity: Benzylpenicillin and Clarithromycin
Add Flucloxacillin if Staphylococcus suspected AND treatemngt for 14 days
Add Vancomycin if MRSA
What is the treatment for HAP
Early onset (under 5 days of being in hospital) use Co-amoxicillin or Cefuroxime Severe or over 5 days use an antipseudomonal penicillin or broad spec cephalosporin or Quinolone Add Vancomycin if MRSA Add Aminoglycoside for pseudomonas aeriginosa
what are the antibiotics used for meningitis or meningococcal septicaemia
causative agent Neisseria meningtidis
Benzylpencillin
Cefotaxime if pen allergy
Chloramphenicol if immediate pen allergy
what are the abx used for osteomyelitis
flucloxacillin
clindamycin if pen allergies
if MRSA suspected Vancomycin
What are Abx used for conjuctivitis
bacterial- chloramphenicol
What are Abx used for Impetigo
causative agent is staphylcocci aureus
Fusidic acid 7 days if small areas
Flucloxacillin for 7 days if larger areas
What are Abx used for cellulitis
causative agent is staphylcocci aureus
Flucloxacillin
What are Abx used for animal and human bites
causative agent is staphylcocci aureus
co-amoxiclav or
Doxycycline and metronidazole
What are Abx used for mrsa (skin and soft tissue)
causative agent is staphylococci aureus
Tetracycline OR Sodium fusidate and rifampicin Alternatively Clindamycin If severe use glycopeptide if this is unsuitable Linezolid
What are Abx used for gingivitis: acute necrotising ulcerative/ periapical/ peridontal abcess periodontitis
Dental treatment are usually treated with Metronidazole
Alternatively they can be treated with doxcycline (peridontitis) or amoxicillin
change abx if no change in 48 hrs : may combine penicillin or macrolide with metronidazole
What are Abx used for sore throat
causative agent streptococci
phenoxymethylpenicillin
if severe try benzylpenicillin
clarithromycin if pen allergic
What are Abx used for sinusitis
Amoxicillin or
Clarithromycin or\
Doxycycline
What are Abx used for otitis externa
causative agent staphylococci aureus
flucloxacillin
clarithomycin if pen allergic
treat is sytemically unwell
What are Abx used for otitis media
Amoxicillin
Clarithromycin if pen allergic
treat if no improvement in 72 hrs or under 2 years old or earlier systemic symtoms
when is amikacin used
for gentamicin resistant gram -ve bacilli
when is neomycin used
bowel sterilisation
it is parenterally toxic
when is streptomycin used
used for mycobacterium in TB
When and how is tobramycin administered
by inhalaltion for pseudomonal infections in cyctic fibrosis
what are the plasma monitoring requirements for gentamicin
monitor after 3-4 doses and a dose change
more frequently and earlier in renal impairment
what is the treatment used for tuberculosis
RIPE
Initial Phase: For 2 months Rifampicin Isoniazid Pyrazinamide Ethambutol Continuation phase: 4 months Rifampicin Isoniazid
What medications are used for oral thrush
Nystatin (POM)
Miconazole oral gel (P) daktarin oral gel
which medications are used for vulval or vaginal thrush
Oral fluconazole 150mg for one dose or a topical imidazole e.g clotrimazole
which medications are used for tinea capatis, corporis, cruris and pedis
miconazole, clotrimazole or terbinafine (for athletes foot)
which medication is used for tinea ungiium (fungal nail infection)
Amorolfine
Which medication is used for HSV-1
Aciclovir
what are the treatment options for malaria (falciparum malaria)
quinine
malarone
riamet (artemether with Lumefantrine
what is the name of the drug used for non-falciparum malaria
chloroquine
which of the anti-malarial tablets are taken once weekly
mefloquine and chloroquine
which of the anti-malarial tablets are taken once daily
malarone, proguanil and doxycyline
which of the malaria prophylaxis medications are POM
Malarone, Doxycycline, Mefloquine
which of the malaria prophylactic medications are P
Proguanil, chloroquine and chloroquine with proguanil
what is Olseltamivir used for
prophylaxis of influenza symptoms by 1 day for at risk groups: 65 +, immunocompromised, diabetes mellitus etc
what are the s/e associated with cephalosporins
hypersensitivity- don’t give in history of pen hypersensitivity. If essesntial give cefuroxime
antibiotic associated colitis- most common in 2nd and 3rd cephalosporins
what are the s/e associated with most penicillin’s
pen allergy-rash
Atopic allergies: higher risk of anaphylatic reactions
true allergy: immediate rash, hives
if infection is serious then do not hold
don’t use other beta lactams such as cephalosporins, carbapenems, monobactams
why should penicillin’s not be given intrathecally
encephalopathy- cerebral irritation which can be fatal
what are the s/e associated with amoxicillin
cholestatic jaundice- don’t take for over 14 days
should ampicillin be taken before or after food
before
what are the s/e associated with flucloxacillin
cholestatic jaundice and hepatitis up to 2 months after treatment
risk is increased with age and exceeding 14 days of treatment
should flucloxacillin be taken before food or after food
before food
what are the S/E associated with vancomycin when given parenterally
Nephrotoxicity
ototoxicity
Red mans syndrome: flushing of upper body caused by rapid infusion. can be associated with hypotension and bradycardia
Blood dyscrasias: thrombocytopenia, agranulocytosis
Stevens- Johnson’s syndrome: itching, rashes, toxic epidermal necrolysis
Thrombophlebitis: pain and inflammation of the veins at the infusion site
Monitoring requirements for parenteral vancomycin
renal function
auditory function
FBC
What are the s/e associated with macrolides
GI effects N&V, abdo discomfort and diarrhoea (mostly with erythromycin) QT prolongation- risk factors include: bradycardia, heart disease, hypokalaemia, hypomagnesaemia, concomitant use of QT prolonging drugs Hepatoxicity ototoxicity at high doses
Mnemonic to remember moa of drugs that work on 30 subunit and 50 subunit
Buy AT 30 CELL at 50
Aminoglycosides Tetracyclines Chloramphenicol/clindamycin Erythromycin- macrolides Linezolid
