Infections Flashcards
Before presiding an antibacterial what 3 things should be considered?
- Patient
- Causative organism
- Risk of bacterial resistance
What Patient factor should be considered?
- Allergy
- Renal impairment
- Hepatic impairment
- Immunocompromised
- Ability to tolerate the drug by mouth
- Severity of illness
- Risk of complications
- Ethnic origin
- Age
- Other medication
- Pregnant/breastfeeding or taking oral contraceptives
After how long do you review IV antibacterial therapy
48 hours. Consider stepping down to oral antibacterial therapy
What do B-road spec antibiotics cause. In terms of adverse reactions?
B-road spectrum antibiotics are most likely to be associated with adverse reactions. Such as:
- fungal infection
- antibiotic associated colitis
- vaginitis
- pruritis ani
What is the early management of sepsis?
Anyone identified as being at high risk of severe illness or death due to sepsis need to be given the following:-
- Broad spec antibacterial @ max dose (within 1 hour)
- Microbiological samples need to be taken without any delay prior to antibiotics, then reassess and change
- Identify the source of the infection
- Iv fluids
- Inotropes
- Vasopressors
- Oxygen
- Check patient parameters: - lactate concentrate - blood pressure.
Monitor no less than every 30 minutes
Antibiotic option - MRSA suspected
Vancomycin
Antibiotic option - anaerobic infection
Metronidazole
Antibiotic option - streptococcal infection
- phenoxymethylpenicillin (Pen V)
- Azithromycin/clarithromycin/erythromycin (macrolid)
Antibiotic option - staphylococci
Flucloxacillin
Diabetic foot infections
Mild
- flucloxacillin
- pen allergy - clarithromycin, doxycycline
- pregnancy - erythromycin
Moderate - severe
Dual antibiotics - oral or IV
- Flucloxacillin +- IV gentamicin, metronidazole
- co-amox +- Iv Gentamicin
- IV ceftriaxone + metronidazole
For penicillin allergy
- co-trimoxazole +/- iv gentamicin
And/or metronidazole.
Otitis externa treatment
- causative agent
Usually caused by pseudomonas aeruginosa, staphylococcus aureus.
Pseudomonas - ciprofloxacin (aminoglycoside)
Staphylococcus - Flucloxacillin
Penicillin allergy - clarithromycin or azithromycin
Pregnancy - erythromycin
Which drugs are safe in pregnancy
- Penicillin
- Macrolid - erythromycin
- Most cephalosporins not known to be harmful (some are avoid)
- Gluycopeptide (teicoplanin/vancomycin’s) - benefits > risks
- clindamycin - not known to be harmful in second and third trimester.
AVOID
1. Aminoglycosides - risk of auditory and vestibular nerve damage in infants when given in 2nd or 3rd trimester
2. Quinolones
3. Co-trimoxazole - trimethoprim is folate antagonist. Avoid in 1st and 3rd trimester (neonatal haemolysis and methaemaglobinaemia).
4. Tetracyclines
5. Chloramphenicol
6. Tetracycline
Treatment of otitis media
Commonly seen in children, usually caused by virus, self limiting.
Both virus and bacteria can co-exist
Treatment
1st line. Amoxicillin
2nd line. Co-amoxiclav (worsening symptoms despite 2-3 days of antibacterial treatment)
Penicillin allergy
1st line. Clairthromycin or erythromycin
2nd line. Consult local microbiologist.
Eye infection - conjunctivitis
- chloramphenicol
Treatment in gastrointestinal infections
- gastroenteritis
- campylobacter enteritis
- diverticulitis
- salmonella
- shigellosis
- typhoid fever
- c.diff
- Billary tract infection
- peritonitis
- dialysis associated peritonitis
Gastroenteritis - self limiting
Campylobacter enteritis -
macrolid or ciprofloxacin
Diverticulitis
UNCOMPLICATED
- co-amoxiclav
-cefalexin with metronidazole
- trimethoprim with metronidazole
- ciprofloxacin with metronidazole
COMPLICATED - IV
- Co-amoxiclav with metronidazole
- cefuroxime with metronidazole
- amoxicillin with gentamicin + metronidazole
- ciprofloxacin with metronidazole
Salmonella
- ciprofloxacin
- cefotaxime
Shigellosis
- ciprofloxacin
- azithromycin
- amoxicillin if sensitive
Typhoid fever
- cefotaxime or ceftriaxone
- azithromycin
- ciprofloxacin
C-diff
- Vancomycin
- fidaxomycin
Life threatening c-diff - vancomycin + IV Metronidazole.
Biliary tract infection
- ciprofloxacin
- gentamicin
- cephalosporin
Peritonitis
- cephalosporin + metronidazole
- gentamicin + metronidazole
- gentamicin + clindamycin
- piperacillin with tazobactam
Peritoneal dialysis associated peritonitis
- vancomycin + ceftazidine
Added to the dialysis fluid
- vancomycin (added to fluid) + ciprofloxacin by mouth
Treatment of gastroenteritis
Self limiting - antibiotics not indicated
Treatment of campylobacter enteritis
Self limiting
Treat if immunocompromised or severe infection
- clarithromycin (azithromycin or erythromycin)
- ciprofloxacin
Treatment of acute diverticulitis
Acute diverticulitis + systematically well. - watchful waiting and no prescribing strategy.
Acute diverticulitis + systemically unwell/immunocompromised or have significant co-morbidities -
Antibacterial prescribing strategy should be offered - oral antibacterial
Suspected or confirmed uncomplicated - ORAL
1st line - co-amoxiclav
2nd line - cefalexin + metronidazole
- trimethoprim + metronidazole
- ciprofloxacin + metronidazole
Suspected or confirmed complicated - IV
1st line - co-amoxiclav or cefuroxime + metronidazole
- amoxicillin + gentamicin + metronidazole
Penicillin allergy
Ciprofloxacin + metronidazole
Treatment for salmonella
Only treat severe or invasive infection
Or if there is a high risk of invasive infection because the patient is immunocompromised, has haemoglobinopathy or the child is under 6 months.
Treatment - ciprofloxacin
- Cefotaxime
Treatment of shigellosis
Antibacterial not indicated in mild cases
If given
- ciprofloxacin
- azithromycin
- amoxicillin if sensitive
Treatment of typhoid fever
Sensitivity needs testing
- cefotaxime or ceftriaxone
- azithromycin
- ciprofloxacin
Treatment of c.diff infection
What happens?
Complications?
Why?
Risk factors?
Treatment?
C.diff occurs when the normal guy bacteria is killed. The c.diff bacteria produces toxins which damages the lining of the gut causing DIARRHOEA.
Infection can be mild to life-threatening
Complications include - pseudomembranous colitis, toxic megacolon, colonic perforation, sepsis and death.
Most common in pts who have taken broad-spec antibiotics, multiple or for long periods.
- clidamycin
- cephalosporin
- fluroquinolones
- B-road spectrum penicillin
Risk factors
- acid suppressing drugs
- age over 65
- prolonged hospitalisation
- underlying co-morbidities
- being around those with c.diff
- previous history of c.diff
Treatment
1. Vancomycin
2. Fidaxomycin
Life-threatening - oral vancomycin + IV metronidazole.
Treatment of bacterial vaginosis
- oral metronidazole
Duration of treatment is 5-7 days - topical metronidazole for 5 days
- topical clindamycin for 7 days
Treatment of Uncomplicated genital chlamydia infection
Contact tracing recommended
- 1st line - doxycycline
- erythromycin
Treatment of Gonorrhoea - uncomplicated
Obtain cultures
Contact tracing
If less than 14 days since exposure - treat
If more than 14 days since exposure - test and if positive treat
Sex needs to be avoided for 7 days after pts and partners have completed treatment.
1st line: ceftriaxone
- ciprofloxacin if sensitive
- gentamicin plus azithromycin if allergy or contra-indicated.
- cefixime plus azithromycin
- azithromycin if all unable to take
Treatment of pelvic inflammatory disease
Contact tracing recommended
- doxycycline + metronidazole + single dose of i/m ceftriaxone
- ofloxacin and metronidazole
Duration of treatment is 14 days
Severely Ill patients - doxycycline + IV Metronidazole + IV ceftriaxone then switch to oral doxycycline + metronidazole
Treatment if syphilis
Contact tracing recommended
- benzathine benzylpenicillin
Single dose normally
Pregnancy second dose after a week
Alternatives
- doxycycline
- erythromycin
Duration of treatment is 14 days
If late syphillis after two years
Benzathine benzylpenicillin once weekly for 2 weeks
Doxycycline (alternative) duration is 28 days
Treatment of sinusitis
Not to generally treat
Delayed prescription for pts systemically unwell and symptoms present for around 10 days.
1st line - (non- life threatening) phenoxymethylpenicillin
2nd line - worsening symptoms or systemically very unwell - co-amoxiclav
PENICILLIN ALLERGY - clarithromycin or doxycycline
PREGNANCY- erythromycin
Treating oral bacterial infection
Dentoalveolar abscess - phenoxymethylpenicillin
- amoxicillin is better absorbed
- co-amoxiclav is active against beta lactamase producing bacteria or if severe dental infection
- metronidazole - anaerobic infections, penicillin allergies, resistance to penicillin.
- cefalexin or cefradine (cephalosporin) used in oral infections. Others offer little advantage.
- doxycycline (effective against oral anaerobes) longer half life than oxytetracycline or tetracycline
- macrolids - useful in penicillin allergies or resistance to penicillin
Clindamycin should not be used routinely
If the oral infection fails to respond to antibiotics within 48 hours, the antibacterial should be changed.
Failure to respond may also be due to incorrect diagnosis, lack of other measures like drainage, poor host resistance, or poor patient compliance.
Treatment for bronchiectasis (non CF) Acute
Treatment for COPD
Treating an acute cough
Treating community acquired pneumonia
Treating hospital acquired pneumonia
Treatment for impetigo
Depends on the type and severity
Non bullous impetigo - most common
Bullous impetigo - not as common
Localised non bullous -
1. topical hydrogen peroxide 1% cream
2. Fusidic acid or mupirocin
3. Flucloxacillin or macrolid
Wide-spread non bullous, systemically well and no high risks of complications
Topical or oral antibacterial
1. Fusidic acid or mupirocin
2. flucloxacillin or macrolid
Non-bullous, unwell or high risk of complication / bullous impetigo
ORAL antibacterial
1. Flucloxacillin or macrolid
NOT TO GIVE BOTH ORAL AND TOPICAL TOGETHER.
Treatment for cellulitis
- Swab for microbiological testing
- Drawing around and monitor can be considered
- Manage any underlying conditions
- diabetes
- venous insufficiency
- eczema
- oedema - Refer patients to hospital if signs and symptoms suggest more serious illness.
- orbital cellulitis
- osteomyelitis
- septic arthiritis
- necrotising fasciitis
- sepsis
TREATMENT
1. Oral or Iv - flucloxacillin
2. Clarithromycin/erythromycin/doxycycline
Infection near the eye or nose
3. Co-amoxiclav
4. Clarithromycin + metronidazole
Severe infections
5. Co-amoxiclav
6. Clindamycin
7. Iv cefuroxime
8. IV ceftriaxone
MRSA
+ vancomycin / teicoplanin / Linezolid
If atleast 2 separate episodes in 12 months. Consider prophylactic antibiotic.
Review every 6 months
Treating leg ulcers
Takes more than 4-6 weeks to heal.
Signs and symptoms
- redness
- swelling spreading beyond the ulcer
- localised warmth
- increased pain
- fever
Step 1
Manage any underlying causes
- venous insufficiency
- oedema
Step 2
Offer treatment to those with signs and symptoms of infection
Step 3
Take a sample if the symptoms are worsening despite treatment or have not improved.
Review the choice of treatment
Treatment options
Not severely unwell
1st line - flucloxacillin
Alternative - erythromycin/clarithromycin or doxycycline
2nd line - co-amoxiclav
Alternative- co-trimoxazole in pen allergies
Severely unwell
1st line -
- IV flucloxacillin +/- metronidazole or gentamicin
- iv co-trimoxazole +/- IV gentamicin or metronidazole (penicillin allergies)
2nd line
- IV pipercillin with tazobactam
- IV ceftriaxone +/- metronidazole
MRSA
+ IV vancomycin/teicoplanin/Linezolid
Treating insect bites and stings
DOES NOT NEED ANTIBIOTICS.
Redness, pain and swelling is often caused by inflammatory or allergic reactions.
Symptoms rarely last longer than 10 days
Tick bite = Lyme disease
Outside of UK - Treat
Signs and symptoms of infection
- TREAT AS CELLULITIS
1. Flucloxacillin
2. Clarithromycin/erythro/doxycycline
Treatment for human and animal bites
Assess for risk of tetanus, rabies or blood borne viral infection.
- Clean wound by irrigation and debrided as necessary
- Refer patient to hospital if signs of more serious infection or condition.
- Take swab
- Offer prophylaxis antibiotic
For cats, human and dogs and other traditional pets.
TREATMENT OPTIONS
1. Co-amoxiclav
2. Doxycycline with metronidazole
IV
3. Co-amoxiclav
4. Cefuroxime with metronidazole
5. Ceftriaxone with metronidazole
Drugs - Aminoglycosides
- Not absorbed from the gut
- Given by injection for systemic infections
- when used for blind therapy, usually given with metronidazole or a penicillin (or both)
- loading and maintenance dose is calculated based on pts weight and renal function.
- adjustments of doses are made based on serum gentamicin concentration
- high doses are occasionally needed for serious infection especially in neonates, CF, or immunocompromised.
- treatment should usually not be longer than 7 days
- neomycin is too toxic for parenteral administration.
- once daily dozing is more convenient however should be avoided in 4 people
1. Endocarditis caused by gram positive bacteria
2. HÁČEK endocarditis
3. Burns of more than 20% of total body SA
4. If the creatinine clearance is less than 20ml/minutes.
MHRA - increased risk of deafness in patients with mitochondrial mutations
- to minimise the risks of adverse effects continuous monitoring of renal and auditory function as well as hepatic and laboratory parameters
Side-effects
1. Ototoxicity
2. Nephrotoxicity
Pregnancy
- risk of auditory and vestibular nerve damage in infants when ahminoglycosides are used in the second and third trimester.
Monitoring requirements
- after 3/4 doses in multiple daily dose regimen and after a dose change.
- sample taken after an hour of administration.
- doses adjusted based on peak and trough concentration.
Gentamicin
- to avoid excessive dosage in obese patients use ideal body weight for height to calculate parenteral dose
- MHRA: histamine- related adverse drug reactions with some batches.
- no longer than 7 days course
Must determine serum conc in:-
1. Elderly
2. Obese
3. High doses
4. Renal impairment
5. Cystic fibrosis
Monitoring - multiple daily dosing
- one hour peak conc 5-10mg/liter
- pre dose trough conc < 2mg/liter
Endocarditis = 2-5mg/l and < 1mg/l
Side effects
1. Ototoxicity
2. Nephrotoxicity
Drugs - carbapenams
- beta lactam antibacterials
- not active against MRSA
- used in severe and complicated infections
- IMIPENEM partially inactivated in the kidney by enzymatic activity and is given with CILASTATIN an enzyme inhibitor which blocks the renal metabolism. The other carbipenams are fine
- MEROPENEM has less seizure inducing potential and can be used to treat CNS infections
AVOID if immediate hypersensitivity reactions to beta lactam antibacterials
AVOID in PREGNANCY
Drugs - Cephalosporins
- Broad spectrum
- excretion is principally renal
- penetrate the cerebrospinal fluid poorly unless the meningis is inflamed.
- cross reactivity between penicillin and 1st and 2nd generation cephalosporin - upto 10% and 2-3% with 3rd generation.
- MoA :- attach to the penicillin binding protein to interrupt cell wall synthesis, leading to bacterial cell lysis and death.
The generations of cephalosporin.
Check image in favourites
Cefazolin
- 1st generation
- avoid in pregnancy
- blood disorders - including leukopenia, granulocytopenia, thrombocytopenia, lymphopenia, eosinophilia, and increased leucocytes are reversible.
Cefaclor
- 2nd generation
- associated with protracted skin reactions especially in children.
Ceftriaxone
- third generation
- precipitates of calcium ceftriaxone can occur in the gall bladder and urine (in the young dehydrated or those immobilised) consider discontinuing if symptomatic.
Teicoplanin
- glycopeptide antibiotic
- similar to vancomycin but has significant longer duration of action which means it can be given as once daily dose after the loading dose.
- active against aerobic and anaerobic gram positive bacteria including multi-resistance staph
- should not be given by mouth for systemic infection because it’s not absorbed.
- associated with a lower incidence of nephrotoxicity than vancomycin
- pregnancy - only if benefits > risks
Vancomycin
- narrow therapeutic index
- active against aerobic and anaerobic gram positive bacteria including multi-resistant staph
- penetration into the cerebrospinal fluid is poor
- should not be given by mouth for systemic infections because it’s not absorbed significantly.
Side effects
- high incidence of nephrotoxicity
- ototoxic - discontinue if tinnitus occurs
- red-man syndrome - flushing of the upper body due to rapid infusion and can be associated with hypotension and bronchospasms
- blood dyscrasias
- skin disorders - Steven Johnson syndrome. Toxic epidermal necrolysis. Rash. Itching.
- thrombophlebitis - pain and inflammation at the injection site.
Pregnancy.
- pregnancy if benefits > risks (monitor plasma conc to reduce fetal toxicity)
Monitoring
- initial dose based on body weight and dose adjustment based on serum vancomycin concentration.
- serum vancomycin measurement is taken in the second day of treatment before the next dose if renal function is normal, earlier if there is impairment.
- pre-dose (trough) = 10-20mg/L
- RENAL FUNCTION
- AUDITORY AND VESTIBULAR FUNCTION.
- BLOOD COUNTS, hepatic and urinalysis
Interaction
- avoid drugs that cause ototoxicity - loop diuretics.
Avoid concurrent or sequential use of other ototoxic drugs.
Clindamycin
- used in
1. Steptococci
2. Penicillin resistant staph
3. Anaerobes - well concentrated in the bone and excreted in bile and urine
- contra-indicated in diarrhoea
(Discontinue) - associated with an increase risk of c.diff.
Discontinue if suspected or confirmed. - pregnancy - not known to be harmful in 2nd and 3rd trimester
- monitor liver and renal function if treatment longer than 10 days
Macrolids
- alternative in penicillin allergy
- take with or after food
Side-effects
1. QT interval prolongation
2. Hepatotoxicity
3. Ototoxic at high doses.
Interactions - enzyme inhibitor
- warfarin
- statins
- azithro - once daily dosing
clairthromycin
- BD, dose based on weight
- Avoid in pregnancy (especially 1st trimester)
Erythromycin
- QDS dosing
- MHRA - drug interaction with rivaroxiban
(Increased risk of bleeding)
- MHRA - known risk of infantile hypertrophic pyloric stenosis (found the risk to be the highest in the 1st 14 days after birth) - parents should be advised to seek medical attention if vomiting or irritable with feeding occurs in infants during treatment.
Erythromycin
- QDS dosing
- MHRA - drug interaction with rivaroxiban
(Increased risk of bleeding) - MHRA - known risk of infantile hypertrophic pyloric stenosis (found the risk to be the highest in the 1st 14 days after birth) - parents should be advised to seek medical attention if vomiting or irritable with feeding occurs in infants during treatment.
- can use in pregnancy
