Antimicrobial Therapy Flashcards
Describe the main classes of influenza virus
Type A - most serious, multiple host species, antigenic shift and drift
Type B - seasonal epidemic
Type C - common cold like
Describe the general pharmacology of M2 ion channel blockers and the main ADRs associated with them
E.g. Amantadine, Rimantadine
Limited to Type A
MOA - prevent entry of protons into the virus –> no breakdown of viral coat –> RNA can’t escape
ADRs - dizziness, GI disturbances, hypotension, confusion, insomnia, hallucination
Describe the general pharmacology of neuramidase inhibitors and the main ADRs associated with them
E.g. Oseltamivir, Zanamivir
Use with type A&B
MOA - neuraminidase transmembrane viral protein (enables virion to escape), bind more strongly with the neuraminidase than the competing sialic acid
ADRs - GI disturbances, headache, nosebleeds, respiratory depression, bronchospasm
Understand the difference between time dependent killing and concentration dependent killing
Time dependent killing - successful treatment requires prolonged antibiotic prescience at site of infection but not high concentration e.g. penicillins, cephalosporins, glycopeptides
Concentration dependent killing - successful treatment requires high antibiotic concentration at site of infection but not for too long e.g. aminoglycosides, quinolones
Recall the major sites of action of antibiotics
DNA synthesis
Protein synthesis
Cell wall synthesis
Recall the primary therapeutic reasons for use of antibiotics
Prophylaxis
Post infective treatment
Name some antibiotics that target DNA synthesis
Quinolones e.g. ciproflaxacin
Folic acid antagonists e.g. trimethoprim, sulphonamides
Name some antibiotics that target protein synthesis
Aminoglycosides e.g. gentamicin
Macrolides e.g. erythromycin
Tetracyclines e.g. doxycycline
Name some antibiotics that target cell wall synthesis
B-lactams e.g. penicillins, cephalosporins, carbapenems
Glycopeptides e.g. vancomycin
Describe common antibiotic ADRs
Hypersensitivity Liver, renal problems Ototoxicity Bone marrow suppression CNS toxicity Electrolyte disturbances Clostridium difficile infection Dental problems GI disturbances
Understand the main genetic mechanisms underlying antimicrobial resistance
Chromosomal mutation
Horizontal gene transfer
Briefly describe biochemical mechanisms of antibiotic resistance
Decreased cell permeability (lack of entry)
Active efflux
Enzymatic inactivation of antibiotic
Modification of drug receptor site (altered target)
Synthesis of resistant metabolic pathway
Define the ‘MIC’ of an antibiotic
Minimum inhibitory concentration = minimum concentration of antibiotic required to inhibit growth of a bacterium in vitro
Be aware of the scale of emergent patterns of antibiotic resistance and name the main organisms
E.g. Methicillin resistant staphylococcus aureus (MRSA)
Understand the process of viral replication and describe the main steps involved
Absorption –> Endocytosis –> Endosomal vesicle –> Uncoating –> RNA replication Synthesis of viral protein/New RNA –> Assembly –> Budding –> Release
