Antibiotics! Flashcards
Tazocin = ?
SE/Interaction?
piperacillin + tazobactam
SEs: antibiotic associated colitis (caution C.diff risk- hospital/elderly)
Interaction: kill normal gut flora which synthesise Vit K – Increased effect of warfarin
Broad spec beta lactams?
Amoxicillin, co-amoxiclav
Amox and coamoxiclav - used when?
Treats pneumonia (gram +ve or -ve), UTI (Trimethoprim/Nitrofurintoin are alternatives), as part of combo treatment for H.pylori Co-amoxiclav – hospital acquired infection, intra-abdominal sepsis
Flucloxicilin - classic uses?
Use: Skin and soft tissue infections (SSTIs) e.g. cellulitis (+ benzylpenicillin for severe infection), for osteomyelitis and septic arthritis and other infections e.g. endocarditis
Cephalosporins and Carbapenems, examples? used when?
Interactions?
Cephradine, cefalexin, meropenem, ertapenem
Use: oral (2nd/3rd line) UTI/RTIs, IV = very severe/complicated/antibiotic resistant infections – broad spectrum
Interactions: warfarin – enhance anti-coagulation by killing vit K producing gut flora. Cephalosporins may increase nephrotoxicity of aminoglycosides and carbapenems reduce plasma conc of valproate.
Glycopeptide example?
Vancomycin
Vancomycin used when?
SE?
Gram +ve infection – endocarditis where infection is severe or penicillin allergy/resistance e.g. MRSA and treatment of c.difficile colitis (2nd line after metronidazole)
SEs: thrombophlebitis (pain and inflamm of vein), if infused rapidly anaphylactoid reactions ‘red man syndrome’ – generalised erythema. Can also get hypersensitivity, blood disorders (neutropenia). Can get nephrotoxicity, ototoxicity (tinnitus) esp w/ drugs aminoglycosides, loop diuretics and ciclosporin.
Gentamicin is a… ?
IT is used to treat..?
IT works by…?
Key side effects include…?
Aminoglycoside
Severe infections esp gram -ve (incl. pseudomonas aeruginosa): severe sepsis, pyelonephritis/complicated UTI, Biliary and other intra-abdominal sepsis, endocarditis (Lack activity against streptococci and anaerobes so combine w/ penicillin/metronidazole when organism is unknown)
Mechanism: aminoglycosides bind irreversibly to bacterial ribosomes and inhibit protein synthesis (bactericidal)
SEs: nephrotoxicity (reduced urine output), ototoxity (tinnitus, hearing loss) (worse w/ vancomycin)
Macrolides - name 2
Clarithromycin, Erythromycin
Macrolides –Clarithromycin, Erythromycin uses?
SE?
Interactions?
Respiratory and SSTIs (!when penicillin allergy). Severe pneumonia (+penicillin). Eradication of H. pylori (PPI + Amoxicillin/ metronidazole)
Inhibit bacterial protein synthesis (bacteriostatic – stops growth)
SEs: irritant (N/V/D -oral, thrombophlebitis – IV). Allergy, c.diff, cholestatic jaundice, arrhythmia (prolonged QT interval) and ototoxicity
Acne vulgaris (proprionbacterium acnes), LRTI incl infective exacerbations of COPD, pneumonia and atypical pneumonia, chlamidydial – pelvic inflammatory disease and others e.g. typhoid, malaria, anthrax, lyme disease.
Which class of antibiotics and examples?
Tetracyclines – Doxycycline, Lymecycline (oral)
SE of tetracylicnes?
Contraindications?
Interactions?
SEs: N/V/D. Hypersensitivity. Oesophageal irritation, photosensitivity, discoloration of teeth, intracranial hypertension.
Contra-indications: pregnancy, breast feeding, children <12, avoid: renal impairment
Interaction: Do not give w/in 2 hours of Ca/antacids/iron. Warfarin
Ciprofloxacin - is a..?
Treats..?
SE?
Quinolone
(usually 2nd/3rd line as bacteria rapidly develop resistance and risk of c.diff) : UTI, severe GI infection, LRTI, only oral Ab which can used on pseudomonas aeruginosa
Interactions: divalent cations: Ca/antacids/iron. Inhibits CytP450 increasing toxicity e.g. theophylline. NSAIDs (seizures), prednisolone (tendon rupture), drugs that prolong QT e.g. SSRIs, amiodarone, antipsychotics, macrolides
Metronidazole is a..?
Treats..?
Interactions?
You cannot do what when you are on it?
Anaerobic antimicrobial
C.difficile, oral infections/aspiration pneumonia, surgical and gynecological infections and protozoal infections.
Interactions: Inhibits cytP450 (warfarin, phenytoin). CytP450 inducers can reduce conc. Metronidazole can increase toxicity w/ lithium.
DRINK
First choice for uncomplicated UTI ?
Trimethoprim or Nitrofurantoin
Contra-indications: pregnancy, babies (<3 months), renal impairment. Caution in long-term prophylaxis as this will increase risk of SEs.
No drug interactions.
Cytochrome p450 inducers?
CRAPS GP
Carbemazepines
Rifampicin
Alcohol - chronic
Phenytion
Griseofulvin
Phenobarbitone
Sulphonylureas
These all induce enzymes, so will decrease the amount of a drug, as the induced enzymes metabolise more of the drug. They will decrease the INR, possibly below the therapeutic level, as more warfarin is being metabolised.
Worth noting that carbamazepine and phenytoin induce the enzymes that they themselves are metabolised by, so they induce their own metabolism. I think this is why you have to gradually increase the dose of them
Which drugs inhibit enzymes (P450) and therefore can increase the amount of a drug that is metabolised by the enzymes that are inhibited (as less of the drug is being metabolised)? - these drugs will increase INR as they inhibit warfarin metabolism.
Enzyme Inhibitors - SickFaces.com
Sodium Valproate (anti-epileptic, also used for bipolar disorder)
Isoniazid (used for TB)
Cimetidine (an H2 receptor blocker)
Ketoconazole & fluconazole (anti-fungals)
Fluoxetine (a selective serotonin reuptake inhibitor)
Alcohol - acute consumption & cigarettes
Cardiac failure and liver failure
Erythromycin & clarithromycin (macrolide antibiotics)
Sulphonamides (antibiotics)
.
Ciprofloxacin (a quinolone antibiotic, which can cause tendonitis and tendon rupture)
Omeprazole (a proton-pump inhibitor)
Metronidazole (antibiotic effective against anaerobes)
Grapefruit juice
