bacterial infections Flashcards
what is the use of broad spectrum ABs associated with?
increased c difficile associated disease
so care if prescribing to elderly, GIT disease inc PPIs
dental abscess local measures
achieve drainage of pus - ext/through RCs, drain any ST pus by incision (don’t drain a cellulitis-type swelling)
remove cause where possible
NUG local measures
remove supra and subgingival deposits, OH advice
due to pain may only be able to tolerate limited debridement in acute phase
local measures for pericoronitis
irrigation and debridement
sinusitis local measures
advise steam inhalation (not children)
indications for ABs
evidence of spreading infection: cellulitis, LN involvement, swelling
evidence of systemic involvement: fever, malaise
local measures have failed
indications for ABs - NUG/pericoronitis
systemic involvement or persistent swelling despite local tx
indications for ABs - sinusitis
persistent symptoms and/or purulent discharge lasting at least 7 days or where symptoms are severe
what should ABs be used in conjunction with?
local measures
pts who have taken AB course in prev 6 weeks
increased risk of harbouring bacteria resistant to that drug and should therefore be prescribed an alternative
emergency transfer to hospital
significant trismus
FOM swelling
difficulty breathing
don’t prescribe antibiotics to:
treat pulpitis
prevent dry socket in non-surgical ext
= these are inflammatory causes of pain
prophylaxis to prevent infections after a routine dental surgical procedure
before prescribing ABs what should you do?
refer to BNF and BNFC for drug interactions
advise pts to space out doses as much as possible throughout the day
review within 2-7days (whether or not ABs were prescribed)
contraception - recent change to guidelines
additional precautions no longer required when antibacterials that do not induce liver enzymes are taken with
- combined oral contraceptives (unless diarrhoea/vomiting)
- contraceptive patches or vaginal rings
ABs in this document don’t induce liver enzymes
IE 2008 NICE
ABP against IE not recommended for people undergoing dental tx
IE 2015 review
no evidence it is of benefit (inc in prosthetic joints)
unacceptable to expose pts to the potential adverse effects of ABs in these circumstances
what MOs are usually responsible for dental abscesses?
viridians streptococcus spp or gram - organisms
dental abscess - why are ABs not indicated where infection localised to PR tissues?
indicates infection being adequately managed by immune system
abscess mostly isolated from circulation - v little AB penetration
dental abscess - when are ABs required?
immediate drainage not achieved using local measures spreading infection (swelling, cellulitis, LN involvement) systemic involvement (fever, malaise)
suggest immune response alone not able to adequately manage infection
what is it good practice to measure in a dental abscess pt?
temp - <36 or >38 degrees indicative of systemic involvement
but absence of pyrexia does not preclude ABs if other S+S of spreading infection or systemic involvement are present
dental abscess - compare amoxicillin and phenoxymethylpenicillin (penicillin V)
amoxicillin usually as effective as phenoxymethylpenicillin but better absorbed
dental abscess - what does the amoxicillin/phenoxymethylpenicillin duration depend on?
severity and clinical response, usually 5 days
don’t prolong courses unduly - can encourage development of resistance
dental abscess - if severe infection how should the AB dose be adjusted?
double dose
e.g. EO swelling, eye closing, trismus
dental abscess - what should you do if pt doesn’t respond to the prescribed AB?
check diagnosis and consider referral to a specialist
dental abscess - first line ABs
amoxicillin
phenoxymethylpenicillin
(metronidazole)
dental abscess - amoxicillin
500mg capsules
15 capsules
x3 daily
double in severe infection in adults and children aged 12-17 years
dental abscess - amoxicillin cautions/contraindications
can cause hypersensitivity reactions, inc rashes and anaphylaxis, can cause diarrhoea
- don’t prescribe to pts with history of anaphylaxis, urticaria or rash immediately after penicillin administration - at risk of immediate hypersensitivity
dental abscess - phenoxymethylpenicillin
250mg tablets
40 tablets
2 tablets x4 daily
severe infection in adults - double dose
dental abscess - phenoxymethylpenicillin cautions/contraindications
can cause hypersensitivity reactions, inc rashes and anaphylaxis, can cause diarrhoea
- don’t prescribe to pts with history of anaphylaxis, urticaria or rash immediately after penicillin administration - at risk of immediate hypersensitivity
dental abscess - when is metronidazole indicated?
pts allergic to penicillin
can be used as an adjunct to amoxicillin in pts with spreading infection or pyrexia
dental abscess - what is metronidazole effective against?
anaerobic bacteria
dental abscess - metronidazole
tablets 200mg
15 tablets
x3 daily
for severe infection double dose in adults and children 12-17yrs
dental abscess - metronidazole cautions/contraindications
avoid alcohol (disulfiram-like reaction with alcohol) don't prescribe to pts on warfarin
dental abscess - why shouldn’t 2nd line ABs be prescribed first?
no advantage over 1st line drugs for most pts, could contribute to antimicrobial resistance
use of broad-spectrum ABs associated with increase in clostridium difficile infection
dental abscess - if pt hasn’t responded to 1st line AB prescribed, what should you do?
check diagnosis
either refer pt or consider speaking to a specialist before prescribing clindamycin, co-amoxiclav or clarithromycin
dental abscess - what is clindamycin active against?
gram + cocci, inc streptococci and penicillin-resistant staphylococci
dental abscess - when can clindamycin be used?
if pt has not responded to amoxicillin/metronidazole
dental abscess - risk of clindamycin
can cause the serious adverse effect of antibiotic-associated colitis more frequently than other ABs
dental abscess - what is co-amoxiclav active against?
B-lactamase producing bacteria that are resistant to amoxicillin
dental abscess - when can co-amoxiclav be used?
to tx severe dental infection with spreading cellulitis or dental infection that has not responded to 1st line antibacterial tx
dental abscess - what is clarithromycin active against
B-lactamase producing bacteria
dental abscess - which broad-spectrum ABs are especially high risk of resultant c difficile infection?
coamoxiclav and clindamycin
dental abscess - what should the use of broad-spectrum ABs be restricted to and why?
2nd line tx of severe infections or in cases of severe infection with spreading cellulitis
risk of c difficile infection
dental abscess - clindamycin
150mg capsules
20 capsules
x4 daily, swallowed with water
same for 12-17 yr olds
dental abscess - clindamycin cautions
don’t prescribe to pts with diarrhoea states
advise pt to discontinue use immediately if diarrhoea or colitis develops as clindamycin can cause the SE of antibiotic-associated colitis
dental abscess - coamoxiclav
250/125 tablets 15 tablets x3 daily same for 12-17 yr olds amoxicillin 250mg as trihydrate and clavulanic acid 125mg as potassium salt
dental abscess - coamoxiclav cautions
cholestatic jaundice can occur either during or shortly after use, more common in >65s and in men
- don’t prescribe to pts who have a history of co-amoxiclav-associated or penicillin-associated jaundice or hepatic dysfct
can result in hypersensitivity reactions inc rashes and anaphylaxis, can cause diarrhoea
- don’t prescribe to pts with history of anaphylaxis, urticaria or rash immediately after penicillin administration as these pts are at risk of immediate hypersensitivity
dental abscess - clarithromycin
tablets 250mg
14 tablets
x2 daily
same for 12-17 yr olds
dental abscess - clarithromycin cautions/contraindications
use with caution in pts who are predisposed to QT interval prolongation inc electrolyte disturbances, and those with hepatic/renal impairment
don’t prescribe:
- pregnant/breastfeeding
- taking warfarin/statins
NUG
painful, superficial infection of the gingival margins associated with anaerobic fuse-spirochaetal bacteria
what groups is NUG more common in?
smokers
immunosuppressed
poor OH
pericoronitis
superficial infection of operculum, with occasional local spread, that is often associated with anaerobic bacteria
NUG and pericoronitis first line tx
local measures
when should ABs be used for NUG and pericoronitis?
severe/systemic involvement/persistent swelling despite local measures
ABs for NUG/pericoronitis
metronidazole first choice
alternative - amoxicillin
NUG and pericoronitis - metronidazole
400mg tablets
9 tablets
x3 daily
NUG and pericoronitis - metronidazole cautions/contraindications
avoid alcohol (disulfiram-type reaction) don't prescribe to pts taking warfarin
NUG and pericoronitis - amoxicillin
capsules 500mg
9 capsules
x3 daily
double in severe infection in adults and children aged 12-17yrs
NUG and pericoronitis - amoxicillin cautions
can cause hypersensitivity reactions inc rashes and anaphylaxis, can cause diarrhoea
- do not prescribe to pts with history of anaphylaxis, urticaria or rash immediately after penicillin administration - at risk of immediate hypersensitivity
sinusitis course of illness
generally self-limiting, av duration 2 and a half weeks
sinusitis local measures
advise pt to use steam inhalation (not recommended for children)
sinusitis - indications for ABs
persistent symptoms and/or purulent discharge lasting at least 7 days or if symptoms are severe
sinusitis - ephedrine
nasal drops 0.5%
10 ml
1 drop into each nostril up to 3 times daily when required
same for 12-17 yr olds
advise pt to use for max 7 days
dose can be increased to 2 drops 3 or 4 times daily if required
sinusitis - ephedrine contraindication
don’t use in pts with high bp
sinusitis - AB choices
Phenoxymethylpenicillin
doxycycline
sinusitis - amoxicillin
capsules 500mg
21 capsules
x3 daily
double in severe infection in adults and children aged 12-17 years
sinusitis - amoxicillin cautions/contraindications
can result in hypersensitivity reactions, inc rashes and anaphylaxis, can cause diarrhoea. Don’t prescribe to pts with history of anaphylaxis, urticaria or rash immediately after penicillin administration as these pts are at risk of immediate hypersensitivity
sinusitis - doxycycline
capsules 100mg (/dispersible tablets)
8 capsules
2 capsules on 1st day, followed by 1 capsule daily
swallow whole with plenty of fluid during meals, while sitting or standing
severe infection in adults and >12yrs - 2 capsules daily
sinusitis - doxycycline cautions/contraindications
use with caution in pts with hepatic impairment or those receiving potentially hepatotoxic drugs
do not prescribe
- pregnant/breastfeeding/<12yrs - can deposit on growing bone and teeth (by binding to calcium) and cause staining and occasional dental hypoplasia
- pts taking warfarin
sinusitis - doxycycline SEs
nausea vomiting diarrhoea dysphagia oesophageal irritation and photosensitivity
