Antibiotics- drugs

Question 1

Trimethoprim

Answer 1

Alone in RTI/UTI or in combination with sulphonamide
Widespread moderate but broad spectrum (GP, GN, anaerobes (?))
Side effects- nausea, vomiting, rash, megaloblastic anaemia (folate deficiency)

Question 2

Penicillin (beta-lactam- amoxicillin, flucloxacillin)

Answer 2

Most effective IV but can be given PO- very broad spectrum, unidentified?
Resistance varies- GP, GN, maybe anaerobes
Side effects- few: hypersensitivity, nausea, vomiting, encephalopathy (rare, due to renal impairment)

Question 3

Cephalosporins (modified B-lactam)- cefuroxime, cephalexin, cefotaxime

Answer 3

modified (3rd generation)- cross allergy to penicillins
Broad spectrum- can be used in gram positive and some gram negative (produce beta lactamase)
SE- hypersensitivity, nephrotoxicity, diarrhoea, rash, headache

Question 4

Tetracyclines (t-RNA inhibitor), doxacycline

Answer 4

Widespread resistance (used in GN GP)
Used in renal impairments as alternative to B-lactams + malaria prophylaxis
SE- GI upset if not taken with enough water: photosensitivity

Question 5

Aminoglycosides- Gentamicin, streptomycin, neomycin

Answer 5

Inhibit cell wall synthesis- widespread resistance, can be overcome with pencillin/ vancomycin (used in GP and some GN bacteria)
used in serious GP infections
SE- Sensorineural deafness in adult and foetus, nephrotoxicity, ototoxicity

Question 6

Glycopeptides- vancomycin, teicoplanin

Answer 6

Inhibit cell wall synthesis
Generally only serious staph infections, effective against C.diff
Used in GP, not GN
GI disturbance, hypersensitivity, skin rashes

Question 7

Macrolides- erythromycin, clarithromycin

Answer 7

Inhibits translocation of proteins- genereally good against GP, not GN: exceptions include H.Inf and legionella
SE- GI disturbance, hypersensitivity, skin rashes

Question 8

Quinolones- ciprofloxacin, levofloxacin, ofloxacin

Answer 8

Inhibits DNA transcription- useful against GPs resistant to penicillin
Ciprofloxacin good vs GN cocci
SE- Few: GI disorders, skin rashes, dizziness, headaches
DONT USE WITH THEOPHYLLINE (asthmatics)

Question 9

Nitrofurantoin

Answer 9

Disrupts DNA- effective against most GP cocci and against e.coli (GN) LUTI’s
SE- periperhal neuropathy, GI upset, long term use > lung fibrosis

Question 10

Tetracyclines- doxy,mino, oxytetra

Answer 10

Inhibit protein synthesis- Very broad spectrum, GP res common, GN moderate
Used in acne, chlamydia, cholera, mycoplasma
SE- nausea, vomiting, diarrhoea, discoloration of teeth in paeds, intracranial hypertension