Antimicrobial Chemotherapy Flashcards
What is an antibiotic?
Must be more injurious to pathogenic organisms than to human body.
Stable, easily absorbed, decisively active against living agents of disease, without harmful side effects and when its done should disappear from the patients body.
What is the activity and main uses of Benzylpenicilliin?
Acitivity:
Streptococci
Neisseria
Spriochetes
Main uses:
Soft tissue, pneumococcal, meningococcal, syphilis infections
What is the activity and main uses of Amoxicillin?
Broad spectrum but resistance is common.
UTI and RTI.
What is the activity and main uses of Flucloxacillin?
Staphylococcal infections.
Used on staph aureus.
What is the activity and main uses of Co-amoxiclav?
Broad spectrum including anaerobes.
UTI, RTI, soft tissue, surgical wound infections.
Works on C.diff.
What is the activity and main uses of Piperacillin/Tazobactam?
Broad spectrum including pseudomonas and anaerobes.
Neutropenic sepsis
IV only.
How do cephalosporins work?
Bind and block activity of enzymes responsible for making peptidoglycan (part of bacterial cell wall).
What is the activity and main action of Cefradine?
broad spectrum
UTI and soft tissue infection
Oral
What is the activity and the man action of Cefuroxime?
Broad spectrum
UTI, RTI, surgical prophylaxis
What is the activity and main uses of Ceftriaxone?
Broad spectrum esp good against Gram-neg bacilli .
Hospital infections eg bacteraemia, pneumonia, abdo sepsis.
What is the activity and main uses of Ceftazidime?
Like ceftriaxone but also active against Pseudomonas.
Pseudomonal infections in hospital and in cystic fibrosis.
What is the activity and main uses of Ceftaroline/Ceftbipirole?
Broad spectrum, less gram negative cover, anti MRSA
Liscensed skin and soft tissue infection, endocarditis.
What is the activity and main uses of Gentamicin and Amikacin?
Gram-neg bacilli
Serious Gram-negative infections eg bacteraemia, endocarditis, neutropenic sepsis.
IV/IM only
Renal and ototoxicity.
What is the activity and main uses of Clarithromycin and Erythromycin?
Streptococci, staphylococci, mycoplasma, chlamydia, legionella.
Resp infection, soft tissue infection (if penicillin allergic), STD.
Erythromycin has GI intolerance.
What is the activity and main uses of Azithromycin?
Relatively better for Gram-neg e.g. Haemophilus; Chlamydia
What is the activity and main uses of Ciprofloxacin?
Gram-negative bacilli, incl. Pseudomonas; some activity against staphylococci and streptococci.
complicated UTI;
complicated hospital acquired Pneumonia;
some GI infections.
What are some complications of Ciprofloxacin and Levofloxacin/Moxifloxacin?
Tendinitis
Aortic aneurysm rupture
C.diff
Growing cartilage
What is the activity and main uses of Levofloxacin/Moxifloxacin?
Enhanced activity against staphylococci/
streptococci, less against Pseudomonas;
Active against pneumococcus, Mycoplasma, Chlamydia, Legionella
2nd or 3rd line agent for pneumonia
What is the activity and main uses of Vancomycin and Teicoplanin?
Grampositive bacteria only - streptococci and staphylococci.
MRSA, patients allergic to penicillin, C.diff.
IV/IM only.
Nephrotoxicity.
What is the activity and main uses of Trimethoprim?
Gram-neg bacilli and
some activity against Streptococci and staphylococci.
UTI,
Resp infection,
MRSA
What is the activity and main uses of Co-trimoxazole?
Broad spectrum; Pneumocystis jiroveci.
Respiratory infection,
PCP
Rashes are complications.
What is the activity and main uses of Clindamycin?
Streptococci;
Staphylococci;
anaerobes.
Soft tissue infection,
gangrene
C.diff is a complication.
What is the activity and main uses of tetracycline and
doxycycline?
Streptococci;
Staphylococci;
Chlamydia; rickettsiae;
brucella.
Q fever, Brucellosis, chlamydia, atypical pneumonia, MRSA.
Contraindicated in pregnancy and childhood as it affects teeth and bones.
What is the activity and main uses of Rifampicin?
Mycobacteria
Meningococcus
Staphylococcui
TB, MRSA, meningococcal prophylaxis, complicated staph infections.
Must be used in combination.
What is the activity and main uses of Meropenem?
Broad spectrum including anaerobes and pseudomonas.
2nd or 3rd line for hospital infections.
IV only, last resort antibiotic, very effective.
What is the activity and main uses of Metronidazole?
Anaerobes, protozoa e.g Giardia.
Surgical infections, giardiasis, amoebiasis, trichomonal infections.
What is the activity and main uses of Linezolid?
Gram-positive bacteria only (Streptococci,
Staphylococci,
Enterococci)
2nd line agent for MSSA, MRSA, VRE.
Oral and IV.
Blood and optic neuropathy side effects.
What is the activity and main uses of daptomycin?
Gram-positive bacteria only (Streptococci,
Staphylococci,
Enterococci)
2nd line agent for MSSA, MRSA, VRE.
IV only, inactive in lung.
What is the activity and main uses of Tigecycline?
Very broad spectrum including MRSA, EBSL, anaerobes.
3nd line,
Intra-abdominal sepsis, soft tissue infections.
IV only, ineffective against pseudomonas.
What is meant by empiric therapy?
Therapy indicated without microbiology results.
What is meant by directed therapy?
Therapy indicated based on microbiology results.
What are the principles of prescribing?
Indications for antimicrobials - therapy, prophylaxis.
Diagnosis - diagnosis of infection, severity assessment.
Patient characteristics - age, renal function, liver function, immunocompromised, pregnancy, known allergies.
Antimicrobial selection
What is meant by the 30% rule regarding antimicrobial prescribing facts?
30% of all hospitalised inpatients at any given time receive antibiotics.
over 30% of antibiotics are prescribed inappropriately in the community.
up to 30% of all surgical prophylaxis is inappropriate.
10-30% of pharmacy costs can be saved by antimicrobial stewardship programs.
What are some methods of testing antibiotic resistance?
Sensitivity testing disk diffusion.
Etest - the lower the minimum inhibitory concentration the better.
What are the 4 mechanisms of antibiotic resistance?
Enzymatic inactivation of the drug.
Modified targets for drugs.
Reduced permeability to drug.
Efflux of drug.
What is meant by chromosomal mediated resistance?
Mutation within the gene that codes for drug target or membrane transport system.
What is binary fission?
Method of bacterial cell division.
DNA replicates and divides, the cell then elongates and divides in 2, forming 2 identical bacteria.
What is meant by plasmid mediated resistance?
Plasmids can carry genes for enzymes which degrade antibiotics and modify membrane transport systems.
What are some examples of medically important resistant organisms/
MRSA VRE ESBL CPE Clostridium difficile.
What is MRSA?
Methicillin resistant staphylococcus aureus.
Has an altered binding protein.
can cause severe invasive infections e.g endocarditis, osteomyelitis.
