4. Bacterial infections Flashcards
Why must prescribing of antibiotics be kept to a minimum?
Prolonged courses of antibiotic treatment can encourage the development of drug resistance
Need to preserve the usefulness of existing drugs for future generations.
What local measures can be used for bacterial infections?
Drain pus if present in dental abscesses by extraction of the tooth or through the root canals.
Attempt to drain any soft-tissue put by incision.
However, do not attempt to drain a cellulitis-type swelling.
When is prescribing antibiotics appropriate for oral infections?
There is evidence of spreading infection (cellulitis, lymph node involvement, swelling) or systemic involvement (fever, malaise).
In addition, other indications for Abx are cases of necrotising ulcerative gingivitis or pericoronitis where there is systemic involvement or persistent swelling despite local treatment.
When is prescribing antibiotics appropriate?
- oral infections with evidence of spreading infection (cellulitis, lymph node involvement, swelling) or systemic involvement (fever, malaise)
- necrotising ulcerative gingivitis or pericoronitis where there is systemic involvement or persistent swelling despite local treatment.
- Sinusitis where there are persistent symptoms and/or purulent discharge lasting at least 7 days or where symptoms are severe.
Use antibiotics in conjunction with, and not as an alternative to, local measures.
What should you do if a pt has recently taken a course of Abx (within the preceding six weeks)?
They have an increased risk of harbouring bacteria resistant to that drug and should therefore be prescribed an alternative.
When would you send a pt to A&E due to an oral infection?
When there is
1. significant trismus
2. floor-of-mouth swelling
3. difficulty breathing.
Should antibiotics be prescribed for pulpitis or the prevention of dry socket?
NO!
Abx for tx of pulpitis or the prevention of dry socket in pts undergoing non-surgical dental extractions.
Dental pain arising from these conditions is due primarily to an inflammatory response which should be managed by appropriate sue of analgesics & local measures.
Abx shouldn’t be used as prophylactic prescriptions to prevent infections after routine dental surgical procedure.
Are contraceptive precautions necessary when taking antibacterials?
These antibiotics that we prescribe do not induce liver enzymes therefore additional contraceptive precautions are not required for pts taking short courses of these drugs unless diarrhoea or vomiting occurs.
Is antibiotic prophylaxis prescribed for infective endocarditis risk patients?
The vast majority of patients at increased risk of infective endocarditis will not be prescribed prophylaxis. However, for a very small number of patients, it may be prudent to consider antibiotic prophylaxis (non-routine management), in consultation with the pt and their cardiologist or cardiac surgeon.
What are dental abscesses usually infected with? (which bacteria)
Viridians Streptococcus spp or Gram-negative organisms.
What are local measures to treating dental abscesses?
Drainage, with removal of the cause where possible.
Are Abx appropriate for infection localised to peri-radicular tissues?
Abx are NOT appropriate in cases where the infection is localised to the peri-radicular tissues as this indicates that the infection is being adequately managed by the immune system. Also, in these cases, the abscess is mostly isolated from the circulation, resulting in very little antibiotic penetration.
When are antibiotics indicated for dental abscesses?
Abx are only required if immediate drainage is not achieved using local measures or in cases of spreading infection (swelling, cellulitis, lymph node involvement), or systemic involvement (fever, malaise), all of which suggest that the immune system alone is not capable to adequately manage the infection.
What temperature indicates systemic involvement?
Temperature of <36 or >38 indicates systemic involvement.
Absence of pyrexia doesn’t preclude prescribing of antibiotics if other signs and symptoms of spreading infection or systemic involvement are present.
What is the preferred first line antibiotic? And why?
Phenoxymethylpenicillin.
This is due to its narrower spectrum of activity, which is less likely to drive antimicrobial resistance.
What is the general duration of treatment and what does it depend on?
The duration of tx depends on the severity of the infection and the clinical response but drugs are usually given for 5 days.
Do not prolong courses of treatment unduly as can encourage development of resistance.
How should your prescription change for severe infections?
The dose of amoxicillin, phenoxymethylpenicillin and metronidazole should be doubled.
Severe infections include those cases where there is extra-oral swelling, eye closing or trismus, but is a matter of clinical judgement.
What indicates a severe infection?
Extra-oral swelling
Eye closure
Trismus
What should yo do if the pt does not respond to prescribed antibiotic?
Check diagnosis and consider referral to a specialist.
What are ways to drain pus?
If pus is present in dental abscesses, drain by extraction of the tooth or though the root canals.
If pus is present in any soft tissues, attempt to drain by incision.
Which antibiotics can be prescribed for dental abscesses? First line!
- Amoxicillin Capsules, 500mg. 1 capsule 3x/day for 5 days.
- Phenoxymethylpenicillin tablets, 250mg. 2 tablets 4x/day for 5 days.
For patients who are allergic to penicillin;
3. Metronidazole tablets, 400mg. 1 tablet 3x/day for 5 days.
For severe infections, what is the dose of amoxicillin?
Double the dose.
Amoxicillin Capsules, 500mg. 2 capsules, 3x/day for 5 days.
What hypersensitivity reactions can occur with amoxicillin and phenoxylmethylpenicillin?
Like other penicillins, it can result in hypersensitivity reactions, including rashes and anaphylaxis, and can cause diarrhoea.
Do not prescribe amoxicillin/phenoxymethylpenicillin to patients with a history of anaphylaxis, urticaria or rash immediately after penicillin administration as these individuals are at risk of immediate hypersensitivity.
What is the dose of phenoxymethylpenicillin for severe infection?
Phenoxymethylpenicillin tablets, 250mg. 4 tablets, 4x/day. = 1g four times daily.