Antibiotic Prescribing & Resistance Flashcards
What does an endogenous infection mean?
An infection that arises form an individuals own microflora
What are aerobic bacteria?
Bacteria that grows in the presence of oxygen
What are capnophilic bacteria?
Bacteria that grows in the presence of carbon dioxide
What are facultative bacteria?
Bacteria that can grow in the presence OR absence of oxygen (as opposed to obligate aerobes)
What are anaerobic bacteria?
Bacteria that grows in the absence of oxygen
What colour stain will gram POSITIVE bacteria produce?
Purple
What colour stain will gram NEGATIVE bacteria produce?
Red (/pink)
What are the types of purulent dental infections?
- Periapical abscess
- Periodontal abscess
- Ludwig’s Angina (& Severed Odontogenic Infections)
- Osteomyelitis of the jaws (incl. bisphosphonate osteonecrosis)
- Actinomycosis
What is Ludiwg’s Angina? What is the treatment for this?
- Combination of abscess and cellulitis (inflammation of the underlying CT)
- Affecting submandibular and sublingual spaces (bilaterally)
- FOM raised and tongue pushed up & back, systemically unwell and often difficulty swallowing saliva
- Airway at serious risk!
- Surgical drainage and AB (usually IV)
- Treat tooth/teeth that caused infection
What bacteria are commonly involved in Ludwig’s Angina?
- Gram NEGATIVE bacilli (anaerobic)
- Streptococcus anginosus
- Anaerobic streptococci
What is osteomyelitis of the jaw? What is the treatment for this?
- Infection of the bone of the maxilla and/or mandible
- Spread of infection may be caused by decreased host immunity (diabetes), impaired vascularity of bone (radiotherapy, Paget’s), MRONJ, fractures (surgery)
- IV AB –> Oral AB
- Surgery (removal of infected bone)
What bacteria are commonly involved in osteomyelitis of the jaw?
- Gram NEGATIVE bacilli (anaerobic)
- Streptococcus anginosus
- Anaerobic streptococci
- Staphylococcus aureus (‘clumps of grapes’ on stain)
What is cervico-facial actinomycosis? And what is the treatment for this?
- Persistent low grade infection with multiple sinuses
- Usually caused by dental infections, trauma
- Surgical drainage and removal of necrotic tissue
- AB: Amoxicillin (500mg 3x daily up to 6 weeks), alternative –> Doxycyline (100mg 1x daily)
What bacteria is commonly associated with cervico-facial actinomycosis?
Actinomyces israelii
What is a periapical abscess? What is the treatment for this?
- Dental infection resulting in the collection of pus around the apex of a tooth
- Tooth usually TTP and non-vital, may be discoloured with hx of trauma/ RCT
- XR = loss of lamina dura
- Drainage of pus: via root canal, incision of fluctuant abscess, extraction (LA/GA)
- -> Palatal/ buccal abscess can be drained via incision of overlying mucosa
- Cover AB: IF SYSTEMIC INVOLVEMENT
What is a periodontal abscess? What is the treatment for this?
- Dental infection arising from pre-exisitng pocket
- Tooth usually painful on lateral movements, vital, may be mobile
- XR = loss of alveolar crest
- Drainage of pus: incision on overlying mucosa
- -> Cover AB: IF SYSTEMIC INVOLVEMENT
- Mechanical debridement to eliminate pocket
- Extraction
What is SIRS?
Systemic Inflammatory Response Syndrome
What are the criteria for SIRS?
Two or more of the following:
- Temp <36 OR >38
- Pulse >90/min
- Resp rate >20/min (or PaCO2 <4.3)
- WCC <4 or >12
What is sepsis?
SIRS + infection (suspected/ confirmed)
What is severe sepsis?
Sepsis + organ dysfunction
What is septic shock?
Low BP (‘shock’, due to sepsis) + unresponsive to fluid resuscitation
What is ‘Sepsis 6’?
Criteria designed to reduced rate of mortality of pts with sepsis
- O2 saturation of 94%
- Take blood cultures
- IV ABs
- Measure serum lactacte and send FBC
- Start IV fluid resus
- Measure urine output
What are the main targets of ABs?
- Cell wall synthesis (beta-lactams)
- DNA replication (metronidazole)
Define ‘Pharmacokinetics’
Encompasses ALL mechanisms by which body metabolises drug
Define ‘Pharmacodynamics’
Time course of antimicrobial activity
What is MIC?
Minimum Inhibitory Concentration = used to determined bacteria susceptibility
What is AB resistance?
LAB = bacterial suspensions VS antibacterial MIC CLINICALLY = infection highly unlikely to respond to max dose of AB
What are the mechanisms for AB resistance?
- Altered target sites
- Enzymatic inactivation (of AB)
- Decrease uptake
- Increased efflux i.e. active pumping to eliminate AB
What are some signs of systemic involvement in dentoalveolar infections?
- SIRS
- Gross swelling
- Trismus
- Regional lymphadenopathy
- Tachycardia
What is the first line of AB cover? (Acute)
- Amoxicillin 500mg (1 capsule 3x daily for 5 days)
- Severe infection; 1,000mg 3x daily i.e. 2 capsules
- Metronidazole 200mg (1 tablet 3x daily for 5 days)
- Severe infection; 400mg 3x daily i.e. 2 tablets
- Phenyoxymethylpenicillin 250mg (2 tablets 4x daily for 5 days)
- Severe infection adults; 1,000mg 4x daily i.e. 4 tablets
what is the second line of AB cover?
Check diagnosis, refer or speak to specialist…
Used if pt do not respond to first line of AB (but no adv)
If no response to Amoxicillin or Metronidazole …
- Clindamycin 150mg (1 capsule 4x daily for 5 days)
- Co-amoxiclav 250/125 (1 tablet 3x daily for 5 days)
- Clarithromycin 250mg (1 tablet 2x daily for 7 days)
