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.
What directions do you give for taking phenoxymethylpenicillin?
Each tablet should be swallowed whole with water, at least 30 minutes before food, as ingestion of phenoxymethylpenicillin with meals slightly reduces the absorption of the drug. If concerned about pt compliance with this regimen, amoxicillin is an appropriate alternative.
When is metronidazole used for dental abscesses?
Metronidazole is effective against anaerobic bacteria and is a suitable alternative for the management of dental abscess in patients who are allergic to penicillin.
It can also be used as an adjunct to amoxicillin in patients with spreading infection or pyrexia.
How is metronidazole prescribed for a dental abscess?
Metronidazole tablets, 400mg. 1 tablet 3x/day for 5 days.
What directions do you need to give when prescribing metronidazole?
Advise patients to avoid alcohol (metronidazole has a disulfiram-like reaction with alcohol).
Do not prescribe metronidazole for patients taking warfarin!!
In which patients is metronidazole contraindicated in?
Pts on WARFARIN
What are the second-line antibiotics for dental abscesses?
Clindamycin, co-amoxiclav and clarithromycin.
These offer no advantage over the first line drugs amoxicillin, phenoxymethylpenicillin and metronidazole for most dental patients. Their routine use in dentistry is unnecessary and could contribute the development of antimicrobial resistance.
Also, the use of broad-spectrum antibiotics is associated with the increase in Clostridium difficile infection observed in both primary and secondary care.
What is the broad-spectrum use of antibiotics associated with?
The increase in Clostridium difficile infection observed both in primary and secondary care.
When should second-line antibiotics be used for dental abscesses?
If a patient has not responded to the first-line antibiotic prescribed, check the diagnosis and either refer the patient or consider speaking to a specialist before prescribing clindamycin, co-amoxiclav or clarithromycin.
What is clindamycin active against?
Gram-positive cocci, including streptococci and penicillin-resistant staphylococci, and can be used if the patient has not responded to amoxicillin or metronidazole.
NB: clindamycin can cause the serious adverse effect of antibiotic-associated colitis more frequently than other Abx.
What is a serious adverse effect of antibiotics more frequently seen in clindamycin?
Antibiotic-associated colitis
When can clindamycin be used?
If the patient has not responded to amoxicillin or metronidazole.
Is active against gram-positive cocci such as streptococci or penicillin-resistant staphylococci.
What is co-amoxiclav active against?
Beta-lactamase-producing bacteria that are resistant to amoxicillin
They can be used to treat severe dental infection with spreading cellulitis or dental infection that has not responded to first-line antibacterial treatment.
When are co-amoxiclav prescribed?
Can be used to treat severe dental infection with spreading cellulitis or dental infection that has not responded to first-line antibacterial treatment.
What is clarithromycin active against?
Beta-lactamase producing bacteria.
Which bacteria are broad-spectrum antibiotics and what can this cause?
Broad-spectrum Abx, especially co-amoxiclav and clindamycin, can result in Clostridium difficile infection
Use of these drugs should restricted to second-line treatment of severe infections only.
What drugs can be prescribed if a patient does not respond to first-line amoxicillin or metronidazole tx, or in cases of severe infection with spreading cellulitis?
An appropriate 5-day regimen is:
- clindamycin capsules, 150mg. 1 capsule 4x/day.
- co-amoxiclav 250/125 tablets. 1 tablet 3x/day.
An appropriate 7-day regimen is:
- clarithromycin tablets, 250mg. 1 tablet 2x/day.
How can clindamycin be prescribed if a pt doesn’t respond to first-line Abx or if severe infection with spreading cellulitis?
Clindamycin Capsules, 150mg.
1 capsule, 4x/day for 5 days.
Advise pt capsule should be swallowed with a glass of water.
In which patients should you not prescribe clindamycin?
Do not prescribe clindamycin to patients with diarrhoeal states.
When would you advise patients to discontinue taking clindamycin capsules?
Advise pt to discontinue use immediately if diarrhoea or colitis develops as clindamycin can cause the side-effect of antibiotic-associated colitis.
How can co-amoxiclav be prescribed in pts who do not respond to first-line Abx or in cases of severe infection with spreading cellulitis?
Co-amoxiclav 250/125 tablets: 1 tablet 3x/day for 5 days
What makes up co-amoxiclav 250/125?
Co-amoxiclav 250/125 tablets are amoxicillin 250mg as trihydrate and clavulanic acid 125mg as potassium salt.
What condition can occur during or shortly after the use of co-amoxiclav?
Cholestatic jaundice can occur either during or shortly after the use of co-amoxiclav; this condition is more common in patients above the age of 65 years and in men.
Like other penicillins, can result in hypersensitivity reactions, including rashes and anaphylaxis and can cause diarrhoea.
Who should you not prescribe co-amoxiclav to?
Do not prescribe co-amoxiclav to patients who have a history of co-amoxiclav-associated or penicillin-associated jaundice or hepatic dysfunction.
Do not prescribe to patient with a history of anaphylaxis, urticaria or rash immediately after penicillin administration as these individuals are at risk of immediate hypersensitivity.
How can clarithromycin be prescribed in pts who do not respond to first-line Abx or in cases of severe infection with spreading cellulitis?
Clarithromycin tablets, 250mg.
1 tablet, 2x/day for 7 days.
Clarithromycin tablets aren’t prescribed in children under 12 years. What is prescribed instread?
Clarithromycin oral suspension
In what patients should you be caution in prescribing clarithromycin in?
Use with caution in patients who are predisposed to QT interval prolongation including electrolyte disturbances and those with hepatic impairment or renal impairment.
In which patient should you avoid prescribing clarithromycin? (3)
- Pregnant women
- Nursing mothers
- Patients taking warfarin or statins
What is necrotising ulcerative gingivitis (NUG)?
Risk factors?
A painful, superficial infection of the gingival margins associated with anaerobic fuso-spirochaetal bacteria and is more common in patients who smoke, the immuno-supppressed and those with poor oral hygiene.
(young patients <35 yo, smokers, calculus, poor OH, nutrient deficiencies, immunocompromised, HIV, drug and alcohol)
What bacteria causes necrotising ulcerative gingivitis?
Anaerobic fuso-spirochaetal bacteria.
What is the first drug of choice of ANUG?
Metronidazole
What is pericoronitis and what bacteria is it often associated with?
Pericoronitis is a superficial infection of the operculum, with occasional local spread, that is often associated with anaerobic bacteria.
Broadly, how do you treat pericoronitis?
In most cases, tx with local measures will be sufficient for resolution of the symptoms. However, where there is a systemic involvement or persistent swelling despite local measures, a three day course of metronidazole can be prescribed.
In what circumstance would you prescribe Abx for pericoronitis and which one?
If there is systemic involvement or persistent swelling despite local measures.
Three-day course of metronidazole
What local measures can be used for ANUG?
Remove supra-gingival and sub-gingival deposits and provide oral hygiene advice.
- Due to the pain associated with NUG, the patient may only be able to tolerate limited debridement in the acute phase.
What local measures can be taken for pericoronitis?
Irrigation and debridement
What prescription do you give for metronidazole for ANUG/pericoronitis?
Metronidazole tablets, 400mg.
Send: 9 tablets
Label: 1 tablet, 3x/day for 3 days.
What advise should be given to patients taking metronidazole?
Avoid alcohol (metronidazole has a disulfiram-like reaction with alcohol).
In which patients do you not prescribe metronidazole for?
Pts taking warfarin
How would you prescribe amoxicillin for patients with ANUG/pericoronitis?
Amoxicillin capsules, 500mg.
Send: 9 capsules
Label: 1 capsule 3x/day for 3 days.
What should the dose of amoxicillin be upped to in cases of severe infection (ANUG or pericoronitis)?
The dose of amoxicillin should be doubled in severe infection in adults and children 12-17.
What reaction can amoxicillin cause?
Amoxicillin, like other penicillins, can result in hypersensitivity reactions, including rashes, anaphylaxis, and can cause diarrhoea.
When should amoxicillin not be prescribed?
In patients with a history of anaphylaxis, urticaria or rash immediately after penicillin administration as these individuals are at risk of immediate hypersensitivity.
How long does sinusitis usually last for?
Sinusitis is a generally self-limiting condition that has an average duration of 2.5 weeks.
Therefore, in suspected cases sinusitis, local measures should be advised in the first instance.
When should Abx be prescribed for sinusitis?
Abx therapy should only be used for persistent symptoms and/or purulent discharge lasting at least 7 days or if symptoms are severe.
What local measures can be used for sinusitis?
Advise the patient to use steam inhalation (not recommended for children).
Sinusitis, if drug treatment is required, what is appropriate to prescribe? (not abx)
Ephedrine Nasal Drops, 0.5% - 1 drop into each nostril up to three times daily when required.
What advise should be given to pts prescribed ephedrine nasal drops?
Use for a maximum of 7 days.
In adults and children over 12, the dose of ephedrine nasal drops can be increased to 2 drops 3 or 4 times daily, if required.
In which patients should you not use ephedrine nasal drops?
Do not use in patients with high blood pressure
If an antibiotic is required for sinusitis, what is prescribed? (first line and second line)
Phenoxymethylpenicillin tablets, 250mg.
2 tablets, 4 times a day for 5 days. Total 40 tablets.
Doxycycline capsules, 100mg.
2 capsules on the first day followed by 1 capsule daily for 5 days. Total 6 capsules.
What advise should be given to patients taking doxycycline capsules for sinusitis?
Advise patients to swallow a capsules whole with plenty of fluid during meals, while sitting or standing.
For severe infections in adults + children over 12 years+, 2 capsules daily can be given.
In which patients do you use doxycycline with caution?
- Pts with hepatic impairment or those receiving potentially hepatotoxic drugs.
Who do you not prescribe doxycycline to?
- Pregnant women
- Nursing mothers
- Children under 12 years
As it can deposit on growing bone and teeth (by binding to calcium) and cause staining and, occasionally, dental hypoplasia.
- Don’t prescribe for pts taking warfarin
What side effects can doxycycline cause?
Nausea, vomiting, diarrhoea, dysphagia, oesophageal irritation and photosensitivity
Why is doxycycline not recommended for children less than 12 years old?
It causing intrinsic staining of developing teeth.
It can deposit on growing bone and teeth (by binding to calcium) and cause staining and, occasionally, dental hypoplasia.
