Antibiotics/antifungals Flashcards
Examples of broad spectrum penicillin
Co-amoxiclav
amoxicillin
spectrum of activity for broad spectrum penicillin
broad spectrum against G and G- cocci and bacilli(rods)
Resistance very likely so mixing it with a beta lactamase inhibitor e.g. co-amoxiclav is helpful for resistant bacteria
What drug type is broad spectrum penicillin
beta-lactam
Indication for broad spectrum penicillin
- Amoxicillin:
- Sinusitis
- otitis media
- com-aq pneumonia
- UTI
- H.pylori in PUD
- Co-amoxiclav
- pneumonia
- UTI
- Intrabdo infection
- Cellulitis
- Bone and join infection
Side effect for broad spectrum penicillin
- Diarrhoea
- Nausea/Vomiting
- Hypersensitivity
- antibiotic -associated colitis
- Penicillin allergy
- Acute liver injury
Contraindication for broad spectrum penicillin
- sever allergy to beta lactam antibiotic
- young people with sore throat
- caution in people with risk of c.diff infection
- Hx of penicillin associated liver injury
Monitoring for broad spectrum penicillin
- check if symptoms are resolving
- stop or review date according to local guidline
Patient education for broad spectrum penicillin
- always check for allergies to any β- lactam antibiotic (including penicillins, cephalosporins, and carbapenems).
- Seek medical advice f rash develops
Key interaction for broad spectrum penicillin
- reduced renal excreation of methotrexate
- Broad-spectrum penicillins can enhance the anticoagulant effect of warfarin by killing normal gut flora that synthesise vitamin K
MOA for broad spectrum penicillin
- Penicillin’s inhibits enzymes responsible for cross-linking peptidoglycans.
- This weakens the bacterial cell wall, reducing its ability to maintain an osmotic gradient causing cell swelling, lysis and death
Examples for narrow spectrum penicillin
flucloxacillin, benzylpenicillin, phenoxymethylpenicillin
Spectrum of activity narrow spectrum penicillin
narrow spectrum against G and G- cocci.
drug type narrow spectrum penicillin
beta-lactam
indication narrow spectrum penicillin
- Benzylpenicillin/pen V
- streptococcal infection e.g.: tonsillitis, pneumonia and endocarditis, meningitis
- Flucloxacillin
- Staphylococcal infection including skin, soft tissue , bone and joint infections , otitis externa and endocarditis
side effects narrow spectrum penicillin
- Diarrhoea
- Nausea/Vomiting
- Hypersensitivity
- antibiotic -associated colitis
- Penicillin allergy
Monitoring narrow spectrum penicillin
- check if symptoms are resolving
- stop or review date according to local guidline
Contraindication narrow spectrum penicillin
- dose reduction in severe renal impairment
- Allergy to penicillin
Key interaction narrow spectrum penicillin
reduced renal excretion of methotrexate
Patient education narrow spectrum penicillin
- always check for allergies to any β- lactam antibiotic (including penicillins, cephalosporins, and carbapenems).
- Seek medical advice f rash develops
MOA narrow spectrum penicillin
- Penicillin’s inhibits enzymes responsible for cross-linking peptidoglycans.
- This weakens the bacterial cell wall, reducing its ability to maintain an osmotic gradient causing cell swelling, lysis and death
- Penicillins comprise a β-lactam ring, responsible for bactericidal activity, and a side chain that modifies their properties and antimicrobial spectrum.
- Some bacteria produce β-lactamase enzymes, which break the β-lactam ring, conferring resistance.
- Flucloxacillin contains an acyl side chain that protects the β-lactam ring and is effective against β-lactamase-producing staphylococci. .
Examples of macrolides
Clarithromycin, azithromycin and erythromycin
Spectrum of activity of macrolides
Broad spectrum , G+ and some G- (h.infuenza & legionella)
what drug type is macrolide
Inhibit translocation of proteins
Indication for macrolide
- Resp, skin and soft tissue infection alternative to penicillin (allergy)
- severe pneumonia (added to a penicillin)
- H.pylori in PUD
side effect for macrolide
decreased appetite
diarrhoea
dizziness
Headache
insomnia
thrombophlebitis when given IV.
prolongation of QT interval
Contraindication for macrolide
- Hx of macrolide hypersensitivity
- severe hepatic impairment
- reduced dose in severe renal impairment
Monitoring or macrolide
- check symptoms resolves
- stop or review date according to local guidelines
Patient education
- Check allergy
- seek advice if rash seen
Key interaction for macrolides
- Erythromycin and clarithromycin (but not azithromycin) inhibit
cytochrome P450 (CYP) enzymes so risk with drugs metabolised by CYP enzyme like statins and warfarin - amiodarone,
antipsychotics, quinine, quinolone antibiotics, and selective serotonin
reuptake inhibitors (SSRIs) → drugs that prolong qt interval
MOA for macrolides
- Macrolides inhibit bacterial protein synthesis.
- They bind to the 50S subunit of the bacterial ribosome and block translocation, a process required for elongation of the polypeptide chain.
- Inhibition of protein synthesis is bacteriostatic (stops bacterial growth), which assists the immune system in killing and removing bacteria from the body.
Examples of metronidazole
metronidazole, tinidazole
spectrum of activity of metronidazole
Anaerobic bacteria and protozoa
Drug type of metronidazole
Inhibits DNA synthesis and breaks down DNA
Indication for metronidazole
- Oropharyngeal G- anaerobes
- dental infection
- human/ animal bite
- aspiration pneumonia
- H.pylori
- Intraabdo infection and Pelvic inflammatory disease
- Protozoal infection
- trichomonal vaginal infection
- amoebic dysentery
- giardiasis
- C.difficle colitis → IV
Side effects of metronidazole
-
IV
- Dry mouth, myalgia, nausea
-
**Topical**
- Skin reaction
-
**Vaginal use**
- pelvic discomfort, vulvovaginal candidiasis
Monitoring for metronidazole
- treatment exceeding 10 days→ do fbc and liver enzyme test
- Stop and review date according to local guidlines
Contraindication for metronidazole
- reduces dose in severe liver disease
- Avoid alcohol
Key interaction for metronidazole
- reduced metabolism of warfarin and phenytoin
- increases the risk of toxicity with lithium.
Patient education for metronidazole
- Check allergy
- DO NOT take alcohol during or for 48 hrs after treatment
MOA for metronidazole
- Metronidazole enters bacteria by passive diffusion.
- In anaerobic bacteria, reduction of metronidazole generates a nitroso free radical.
- This binds to DNA, reducing synthesis and causing widespread damage, DNA degradation, and cell death (bactericidal).
examples of Tetracycline
Doxycycline and lymecycline
Spectrum of activity of tetracycline
Broad spectrum against G+ & G-
drug type of tetracycline
Inhibit protein synthesis
Indication of tetracycline
- Acne vulgaris
- LRTI:
- infective exacerbation of COPD
- Pneumonia
- Chlamydial infection
- Typhoid, malaria and lyme disease
- severe skin, soft-tissue, and abdominal
infections
Side effects for tetracycline
- angioedema
- diarrhoea
- headache
- hypersensitivity
- Photosensitivity
Contraindication of tetracycline
- Pregnancy
- Breastfeeding
- children under or equal to 12 yrs
- caution in renal impairment
Monitoring of tetracycline
- resolution by symptoms
- set a stop and review date
Patient education of tetracycline
- Hx of allergy
- seek help if rash develops
- Taken during a meal with full glass of water
- avoid indigestion remedies and medicine containing zinc or iron 2 hrs before and after taking antibiotic
- During treatment protect skin form sunlight
Key interaction for tetracycline
not given within2 hrs of calcium, antacids or iron
enhance warfarin effect
MOA of tetracycline
- Tetracyclines inhibit bacterial protein synthesis.
- They bind to the ribosomal 30S subunit, which is specific to bacteria.
- This prevents binding of transfer RNA to messenger RNA, interfering with the addition of amino acids to growing polypeptide chains.
- Inhibition of protein synthesis is bacteriostatic (stops bacterial growth), which assists the immune system in killing and removing bacteria.
Spectrum of activity of nitrofurantoin
active against most organism that cause uncomplicated UTI incl. E.coli (G-) and g+
Indication for nitrofurantoin
- first line for acute, uncomplicated lower UTI
- prophylaxis of recurrent UTIs
Side effects for nitrofurantoin
- Diarrhoea
- Hypersensitivity
- chronic pulmonary reaction
- hepatitis
- peripheral neuropathy
Contraindication for nitrofurantoin
- Pregnant women towards term
- babies in first 3 month of life
- G6PD deficiency
- Renal impairment
Monitoring for nitrofurantoin
- resolution of symptoms
- for prophylaxis→ check UTI freq before and after
Patient education for nitrofurantoin
- Check allergy
- Advice urine may term yellow or brown
- If used for prophylaxis then let them know this is long tern and should be renewed
- unexplained symptoms should be reported e.g. pins and needles or breathlessness
Key interaction for nitrofurantoin
- amiodarone
- isoniazid
- metronidazole
- Phenytoin
MOA for nitrofurantoin
- Nitrofurantoin is metabolised (reduced) in bacterial cells by nitrofuran reductase.
- Its active metabolite damages bacterial DNA and causes cell death (bactericidal).
Drug class of vancomycin
this is a glycopeptide antibiotic
Spectrum of activity of vancomycin
narrow against G+
drug type of vancomycin
Inhibit cell wall synthesis
indication for vancomycin
- First line for C. difficile colitis
- complicated skin and soft tissue, bone and joint infections; infective endocarditis
Side effects for vancomycin
- Pian
- Thrombophlebitis
- dizziness
- nausea
- Vancomycin infusion reaction with IV
Contraindication for vancomycin
- caution in people with immune -mediated hypersensitivity
- Hearing impairment (whoa re at risk for ototoxicity
- people at risk for reduced renal function
Monitoring for vancomycin
- parenteral therapy, pre-dose (trough) plasma drug concentrations
should be measured. - Daily measurement of renal function
- Platelet and leukocyte count checked in prolonged courses
- Set a stop and review date
Patient education for vancomycin
- Report any ringing in the ear or change in hearing during treatment
- Check HX of allergy
Key interaction for vancomycin
- loop diuretics
- aminoglycosides
- NSAIDS
- Ciclosporin
MOA for vancomycin
- Glycopeptide antibiotics inhibit growth and cross-linking of peptidoglycan chains.
- This inhibits synthesis of the cell wall in Gram- positive bacteria, causing cell lysis (bactericidal).
- They are inactive against most Gram-negative bacteria, which have a different (lipopolysaccharide) cell wall structure.
Examples of cephalosporin
Cefuroxime, Ceftriaxone, cefalexin, meropenem
spectrum of activity of cephalosporin
broad spectrum , G+ G-
drug type of cephalosporin
Modified beta lactam
Indication of cephalosporin
second line for urinary UTI , Pneumonia and other resp tract infection
side effect of cephalosporin
- Abdo pain
- Diarrhoea
- Dizziness
- Eosinophilia
contraindication of cephalosporin
- used in caution with people risk of c. difficle infection
- Allergy to a beta lactam antibiotic
- Dose reduction in renal impairment
Monitoring of cephalosporin
- resolution of symptoms
- set a stop and review
Patient education of cephalosporin
- check allergy
- seek medical help for any rashes
Key interaction of cephalosporin
enhance warfarin effect
MOA of cephalosporin
- Like penicillins, their bactericidal effect is due to their β-lactam ring.
- During bacterial cell growth, cephalosporins and carbapenems inhibit enzymes responsible for cross-linking peptidoglycans in bacterial cell walls.
- This weakens cell walls, preventing them from maintaining an osmotic gradient, resulting in bacterial cell swelling, lysis, and death.
examples of fluroquinolones
Ciprofloxacin, Levofloxacin, Ofloxacin and moxifloxacin
Spectrum of activity of fluroquinolones
Broad spectrum, best against G-
Cipro great against pseudomonas aeruginosa
Moxi and levo better against G+
drug type of fluroquinolones
Inhibit DNA transcription
Indication of of fluroquinolones
- UTI
- Severe gastroenteritis
- Lower resp tract infection incl. infective exacerbation of copd and pneumonia
Side effect of fluroquinolones
decreased appetite
diarrhoea
dizziness
dyspnoea
Contraindication of fluroquinolones
- pregnancy
- children and young adults
- adults over 60 years
- renal impairment
- people at risk of neurological or cardiovascular morbidity
Monitoring of fluroquinolones
- check resolution of symptoms
- set a stop and review date according to local guideline
patient education of fluroquinolones
- explain potential side effects and that these are prescribed as last resort
- Watch out for any pain, swelling or changes in sensation
- Cipro should not be taken with dairy product
- It must be separated from calcium/iron
supplements and antacids by at least 2 hours
Key interaction of fluroquinolones
- Calcium, iron and antacids reduce absorption of quinolones
- Ciprofloxacin inhibits certain
cytochrome P450 (CYP) enzymes, increasing risk of toxicity from some
drugs, notably theophylline. - Co-prescription of NSAIDs increases
the risk of seizures, and prednisolone increases the risk of tendon rupture.
MOA of fluroquinolones
Quinolones kill bacteria (bactericidal effect) by inhibiting DNA
synthesis.
fluroquinolones are modified quinolones by the addition of a fluorine
