Antibiotic use and abuse

Question 1

How should most oral infections be resolved?

Answer 1

Removal of the cause and establishment of drainage (removal of tooth or opening up the pulp chamber or drainage of abscess)

Question 2

Why should antibiotics not be prescribed for oral infections?

Answer 2

Can cause harm. May be a temporary solution to infection but do not deal with cause

Question 3

Will antibiotics ever help pulpits?

Answer 3

No

Question 4

How can antibiotics cause harm directly?

Answer 4

Fatal anaphylaxis to pencillins
Hypersensitivity reactions
Adverse drug reactions

Question 5

How can antibiotics cause harm indirectly?

Answer 5

Opportunistic infections e.g. c. diff (commensal bacteria in gut die and c. diff thrives)
Resitant organisms (MRSA)

Question 6

Contraindications to antibiotic use?

Absolute and relative

Answer 6

Absolute - known hypersensitivity
Relative - liver disease (affects metabolism)
Kidney disease (tetracylines may worsen renal failure)
Lymphocytic leukaemia, glandular fever - ampicillin and amoxicillin may cause rash
Pre-existing diarrhoea

Question 7

What should be kept in mind when prescribing antibiotics to pregnant or lactating women?

Answer 7

Teratogenic effects on developing fetus
Pharmokinetic or phrarmodynamic alterations
Lactation can effect effectiveness
Breastfed infants exposed to maternal drugs

Question 8

List the categories of adverse effects of antibiotics?

Answer 8

Hypersensitivity/ allergy
Minor adverse drug reaction
Major adverse drug reactions
Developmental

Question 9

What is allergy mediated by? (2)

Answer 9

Antibodies (type I-III) or T cells (type IV)

Question 10

What is the problem with antibiotics and patients on warfarin?

Answer 10

Drug interactions - most antibiotics increase effect of warfarin and bleeding risk is increased

Question 11

What are the 2 uses of antibiotics in dentistry?

Answer 11

Therapeutic (primary or adjunct therapy)

Prophylactic

Question 12

What is the first choice for antibiotics in dentistry? When is it used?

Answer 12

Amoxicillin
Adjunct treatment of dent-alveolar infection, limit spread of infection.
Prevention/treatment of infection in oro-antral communication
Loading dose prior to implant or extraction for high risk of infection patients

Question 13

What antibiotic id the first choice in necrotising periodontal disease and periocoronitis?

Answer 13

Metronidazole (anaerobic flora)

Question 14

What is an appropriate alternative to amoxicillin if the patient is allergic to pencillin?

Answer 14

Metronidazole, clindamycin (more side effects)

Question 15

Patient has very severe infection, what should you prescribe whilst waiting for clinical treatment?

Answer 15

Amoxicillin and metronidazole (if very severe - to widen the spectrum fo activity to be more effective against anaerobes)

Question 16

Why is erythromycin not often used as an alternative to amoxicillin in patients allergic to penicillin?

Answer 16

Some oral bacteria have developed resistance

Question 17

For infections not responding to first line treatment what antibiotics can be given? What is the problem with these?

Answer 17

Clindamycin and co-amoxiclav - GI side effects

Question 18

What should you always do along side prescribing antibiotics?

Answer 18

Treat the cause (either at practice or refer to specialist)

Question 19

Why is amoxicillin first choice?

Answer 19

Broad spectrum

Question 20

When should you not prescribe amoxicillin?

Answer 20

If patient is allergic to penicillin

Question 21

When antibiotics are used as adjunct treatment, what are they used alongside?

Answer 21

Operative treatment

Question 22

List 3 procedures where prophylactic antibiotics may increase success?

Answer 22

Tooth transplantation
Prevention of osteoradionecrosis
advanced implantology

Question 23

Are antibiotics appropriate for alveolar osteitis?

Answer 23

No - this is a fibrinolytic condition

Question 24

Are antibiotics appropriate for inflammatory conditions? List 2 conditions you may see on clinic?

Answer 24

No
Early pericoronitis
Post-op oedema

Question 25

What kind of infection are antibiotics effective against/

Answer 25

Bacterial only

Question 26

4 principles of the use of antibiotics to prevent wound infection?

Answer 26

1. Probability of wound infection must be high
2. Select appropriate antibiotic
3. Initiate therapy at correct time
4. Use for appropriate length of time

Question 27

Within dentistry what are the most likely causes of decreased patient resistance (increased probability of infection)?

Answer 27

Immunocompromised
Immunosupression
Previous jaw radiotherapy

Question 28

Prophylactic antibiotics to prevent infection of wound must be given at the correct time - when is this?

Answer 28

Must achieve high levels of AB in blood clot, so needs to be high at end of surgery.
Clot impenetrable to AB 3 hours after formation
Give AB 1 hour before surgery

Question 29

How to reduce antibiotic resistance?

Answer 29

Minimise unnecessary prescribing - treat cause
Correct AB for correct duration
Complete entire course of treatment