ANTIBIOTICS Flashcards
Penicillin - Antipseudomonal
Piperacillin with Tazobactam
Antipseudomonal:
I: Severe infections + antibiotic resistance (HAI) + immunocompromised
LRTI + UTI
Intraabdominal sepsis
Skin and soft tissue infections
MOA: Weakens cell wall which causes cell swelling, lysis and death. Bactericidal.
SE: GI upset (nausea + vomiting), ABX associated colitis, Hypersensitivity
KI: Reduces renal excretion of methotrexate
CI: Penicillin Allergy
C: people at risk of C diff infections (elderly, inpatients), ↓ dose in pts. with moderate/severe renal impairment.
M: Resolution of symptoms, blood markers (falling c-reactive protein and WBC)
Penicillin - Broad Spectrum
Amoxicillin, Co-Amoxiclav
Broad Spectrum:
I: Susceptible infections (CAP, OM, Sinusitis, UTI) + H.Pylori [ AMOXICILLIN ]
Severe + resistant HAI (RTI, Genitourinary + Abdominal infections, Cellulitis,
Bone + Joint infection) [ CO-AMOXICLAV ]
MOA: Weakens cell wall which causes cell swelling, lysis and death. Bactericidal.
SE: GI upset, ABX associated colitis, Allergy, rash, Co-amoxiclav can cause Acute Liver Injury and jaundice
CI: Hx of allergy
C: Pts at risk of C.diff (elderly, in pts), Hx of Penicillin associated liver injury
↓ dose in severe renal impairment.
M: resolution of symptoms and blood markers (falling c-reactive protein and WBC)
Penicillins
Benzylpenicillin, Phenoxymethylpenicillin
Penicillins:
I: Streptococcal Infection e.g. tonsilitis, pneumonia (w/ a macrolide or tetracycline), endocarditis (with gentamicin), skin and soft tissue infections (with flucloxacillin)
Meningococcal infections e.g. meningitis, septicaemia.
Clostridial infections. e.g. gas gangrene
MOA: Weakens cell wall which causes cell swelling, lysis and death. Bactericidal.
SE: Allergy
KI: All penicillins reduce renal excretions of methotrexate -> ↑ toxcitiy
CI: Penicilin Allergy
C: Renal impairment
M: resolution of symptoms and blood markers
FLUCLOXACILLIN
I: OE, skin infections (Impetigo, erysipelas), cellulitis, bacterial eczema, mild diabetic foot infection, leg ulcer, endocarditis, osteomyelitis (swelling, inflammation of the bone), surgical prophylaxis, primary and secondary prevention of lung infection in cystic fibrosis
MOA: Weakens cell wall which causes cell swelling, lysis and death. Bactericidal.
SE: nausea, vomiting, diarrhoea (GI upset), hypersensitivity, skin reaction, thrombocytopenia ( ↓ platelet count ), ABX associated colitis
CI: Allergy
C: Hepatic impairment, ↓ doses in renal impairment
MACROLIDES
clarithromycin, azithromycin, erythromycin
I: Respiratory, skin and soft tissue infections (alternative to penicillin if allergy)
Severe pneumonia (legionella and mycoplasma)
H.pylori
MOA: inhibits bacterial protein synthesis. bacteriostatic (stops bacterial growth)
SE: Irritant causing nausea, vomiting, abdominal pain and diarrhoea. thrombophelbitis in IV). abx associated colitis, cholestatic jaundice, prolongation of the QT interval (arrythmias) and ototoxicity in ↑ doses
KI: Erythro + Claryithro are CYP inhibitors - Drugs which are metabolised by CYP enzymes (warfarin - ↑ bleeding, statins ↑ risk of myopathy)
CI: Hypersensitvity
C: severe hepatic and ↓ dose in renal impairment, pts that take drugs that prolong QT interval which can lead to arrythmias (amiodarone, antipsychotics, quinine, quinolone ABX and SSRIs)
M: Resolution of symptoms
METRONIDAZOLE
I: ABX associated colitis, oral infection (dental abscess), aspiration pneumonia, surgical/ gynae infection, protozoal infection (trichomonal vaginal infection), perinanal Crohn’s disease
MOA: Anaerobic bacteria. DNA degeneration + cell death (bactericidal)
SE: Nausea + Vomiting (GI upset), hypersensitivity, peripheral + optic neuropathy, seizures and encephalopathy.
KI: Inhibitory effect on CYP inhibitors. Reduces metabolism of warfarin ( ↑ risk of bleeding ) and phenytoin (increasing toxicity)
CI: Alcohol - can cause ‘disulfiram-like’ reaction (flushing, headache, nausea and vomiting
C: ↓ dose in severe liver disease
M: resolution of symptoms. For treatment >10 days, measure FBC, LFT for side effects.
TETRACYCLINE
Doxycline, Lymecycline
I: Acne Vulgaris, LRTI, infective exacerbation of COPD (H.influenzae), Pneumonia + atypical pneumonia (Mycoplasma, Chlamydia). Chlamydial infection (PID)
MOA: Inhibits bacterial protein synthesis. Bacterostatic (stops bacterial growth)
SE: Nausea, vomiting, diarrhoea, hypersensitivity, oesphageal irritation, photosensitivity (sunburn), discolouration + hypoplasia of tooth enamel in children. Rarely ( hepatotoxicity, intercranial HTN)
KI: Should not be given within 2 hrs of calcium, antacids, iron as it can affect abx aborption. It enhances the effect of warfarin.
CI: pregnancy, breastfeeding and children <12 years of age.
C: renal impairment
PC: during a meal, avoid indigestion remedies containing zinc 2 hrs before and after taking treatment, protect skin from sunlight ( sunscreen)
TRIMETHOPRIM
Trimethoprim, Co-trimoxazole
I: Acute UTI, prophylaxis of recurrent UTI, Acne, RTI, prostatitis (Trimethoprim). Pneumocystis pneumonia in immunosuppression (HIV) (Co-Trimoxazole)
MOA: Inhibits bacterial folate synthesis, bacteriostatic (Slowing bacterial growth), ↓ widespread bacterial resistance
SE: Nausea, vomiting, sore mouth (GI upset), skin rash, hypersensitivity, cause haematological disorders (megaloblastic anaemia, thrombocytopenia). Hyperkalaemia
KI: Use with potassium elevating drugs (aldosterone antagonist, ACEi / ARBS). Use with other folate antagonists (methotrexate) + drugs which ↑ folate metabolism (phenytoin) -> ↑ risk of adverse haematological effects. Enhances effect of warfarin.
CI: Pregnancy (First trimester) - fetal abnormalities
C: Folate deficiency, ↓ dose in renal impairment, neonates, elderly, HIV infection.
M: Check if acute infection is resolved with symptoms, long term treatment - FBC monitoring for early detection + treatment of haematological disorders
VANCOMYCIN
I: Endocarditis, ABX associated colitis
MOA: Inhibits synthesis of the cell wall of gram + bacteria, thus lysing and killing the bactera (bactericidal).
SE: Thrombophelbitis (inflammation of vein), red man syndrome, hypersensitivity, IV vancomycin - nephrotoxicity, ototoxicity,neutropenia + thrombocytopenia
KI: ↑ risk of ototoxicity/ nephrotoxicity when prescribed with aminoglycosides, loop diuretics, ciclosporin.
C: Renal impairment, elderly
M: Plasma vancomycin concentration should be measured during treatment (IV therapy), check renal function, platelet and leucocyte counts.
PC: Repor any ringing in the ears, change in hearing as it can only be reversed if treatment is stopped.
CEPHALOSPORIN
Cefalexin, Cefoxatime, Meropenum, Ertapenem
I: 2nd and 3rd lline treatment of urinary and RTI, infections that are very severe and are caused by ABX associated colitis.
MOA: Bactericidal effect due to their b-lactam ring. Causes bacterial cell swelling, lysis and death
SE: nausea, vomiting + diarrhoea (GI upset). ABX associated colitis, hypersensitivity, risk of neurological toxcitiy (seizures)
KI: enhance effects of warfarin. Can increase nephrotoxicity of aminoglycosides.
CI: Allergy, anaphylactic reaction
C: Risk of C diff (inpatients, elderly), Epilepsy, renal impairment
M: Resolution os symptoms
Fluoroquinolones
Ciprofloxacin, Moxifloxacin, Levofloxacin
I: UTI ( gram - ) , Severe gastroenteritis (due to shiegella),
LRTI (gram -, moxifloxacin/ levofloxacin are preferred)
MOA: Inhibits DNA synthesis (bactericidal), bacteria rapidly develop resistance to quinolones.
SE: nausea, vomiting + diarrhoea (GI upset), hypersensitivity, rupture of muscle tendons, prolong the QT interval -> ↑ risk of arrythmias, C. difficile colitis
KI: CYP inhibitor ( ↑ toxcitiy ) in some drugs e.g theophylline. NSAIDS ↑ risk of seizures, caution in patients taking other drugs that prolong the QT interval or causes arrythmias (amiodarone, antipsychotics, macrolide ABX, SSRI)
C: seizures, children, QT prolongation (cardiac disease/ electrolyte disturbance)
