Practice Mgmt_antibiotics

Question 1

What patients are the best candidates for systemic antimicrobial therapy?

Answer 1

Herrera , 2002; Slots, 2004:
Candidates for systemic antimicrobial therapy:
* Patients with CAL loss after adequate conventional therapy
* Aggressive forms of periodontitis
* Predisposing medical conditions (eg. Diabetic patients, Smokers)
* Severe periodontal infection: Periodontal abscess, ANG/P

Question 2

Describe Tetracycline. How do you prescribe it?

Answer 2

Bacteriostatic (30 S), effective against Gram + more than Gram -.
Regimen: 250mg, QID for 14-21 days

Question 3

Describe Minocycline. How do you prescribe it?

Answer 3

Bacteriostatic (30 S), effective against broad expectrum of organisms (more efective on Gram - )
Regimen: 100-200mg, QD for 21 days

Question 4

Describe Doxycyline. How do you prescribe it?

Answer 4

Bacteriostatic (30 S), Same spectrum of activity as minocycline.
Regimen: 100mg first day, then 50mg BID can be taken for for 21 days

or,
Host modulator agent: reduces activity of MMP-8
Regimen: 20mg BID x 9 months

Question 5

What are negative side effects of tetracyclines?

Answer 5

Don’t use for long term (Large dose -resistance)
Gastrointestinal disturbance
Photosensitivity
Dizziness
Renal toxicity
Should be taken 1 hr pior or after food (Calcium, magnesium can bind to it & inactivate it).

Pregnancy (Category D)
Avoid in Children: tooth decoloration will occur (if less than 12 yo), and Hyperplasia of teeth and depressed skeletal growth.
Avoid if taking Carbamazepine (for Seizures): doxycycline half life will decrease.
Avoid if taking Digoxin (for Irregular heart beat): serum levels of digoxin will decrease.

Question 6

Describe Azithromycin. How do you prescribe it?

Answer 6

Bacteriostatic (50 S), effective against anaerobes and Gram - bacilli.
Regimen: 500mg, once a day for 4-7 days or 500mg first day and then 250mg once a day for 5 days

Question 7

Describe Erythromycin. How do you prescribe it?

Answer 7

Bacteriostatic (50 S), Poor efect on Periodontal pathogens (resistance)
Regimen: 250mg, QID for 14-21 days

Question 8

What are the risks of macrolide antibiotics?

Answer 8

Macrolides: Azithromycin, erythromycin
* High incidence of nausea
* Inhibit P450 enzymes
* Azithromycin – Promote QT interval elongation
* Interaction with Cyclosporin , Carbamazepine and Oral anticoagulants (Warfarine) , Cisapride (GI tract motility increase)
* Pregnancy: (Category B)
* Children: adjust dosage
* Elders: Advanced age - not recommended

Question 9

Describe Clindamycin. How do you prescribe it?

Answer 9

Bacteriostatic (50 S), Very effective against gram (-) anaerobes. (PG, PI, Spirochetes)
Regimen: 300mg, TID for 10 days.

Question 10

What are the side effects of Clindamycin?

Answer 10

• Inhibit P450 enzymes
• Pseudomembranous colitis - Clostridium difficile
• Interaction with anti-diarrheals
• Interaction with Muscle relaxants
• Pregnancy (Category B) – No Known reaction
• Elders – Higher frequency of P. Colitis
• Children: adjust dosage
• Erythomycin interaction

Question 11

Describe Ciprofloxacin. How do you prescribe it?

Answer 11

Bacteriocidal (Inhibits DNA synthesis), Very effective against gram (-) rods, staphylococci, all facultative and some anaerobic.
Regimen: 500mg, BID for 8 days.

Question 12

What are the side effects of ciprofloxacin?

Answer 12

• Nausea
• Abdominal pain
• Headache
• Metal taste in mouth
• Photosensitivity
• Interacts with anticoagulats (Warfarine)
• Caffeine
• Cylosporin (Organ transplant): serum levels
• CNS: Psychotic reactions, Paranoia, hallucinations, insomnia, anxiety
• Theophyline (Asthma and COPD): serum levels
• Tendinopathy
• Pregnancy: (Category C) – CONTRAINDICATED
• Children: CONTRAINDICATED

Question 13

Describe amoxicillin. How do you prescribe it?

Answer 13

Bacteriocidal (Inhibits cell wall synthesis), Targets both Gram (+) and Gram (-)
Regimen: 500mg, TID for 8 days.

Question 14

What are the negative side effects of Amoxicillin?

Answer 14

• Interaction with Probenecid (gout and arthritis): level of Penicillin
• Pregnancy: (Category B) – safe
• Children: adjust dose
• Elder: have an increase frequency of anaphilaxys do to prior exposure
• 10% of the population has an allergy to Penicillin (Rash)
• Diarrhea
  *

Question 15

Describe metronidazole. How do you prescribe it?

Answer 15

Bacteriocidal (Inhibits DNA Synthesis) – Targets anaerobic organisms
Regimen: 500mg, TID for 8 days.

Question 16

What are the negative side effects of Metronidazole?

Answer 16

• Metalic taste
• Antabuse effect with alcohol
• Warfarine interaction : anticoagulant efect
• Barbiturates interaction (anti-anxiolytic, enti-epileptics, sedatives and anticonvulsants: efect of Metronidazole.
• Pregnancy: Avoid in 1º trimester (Teratogenicy)
• Children: adjust dosage
• Elders: beware of pharmacokinetics

Question 17

What is the Van Winkelhoff cocktail?

Answer 17

Combination of Metronidazole + Amoxicillin.
Regimen: 250mg, TID for 8 days each drug.

Question 18

What’s an alternative combination besides van Winkelhoff cocktail?

Answer 18

Metronidazole + ciprofloxacin
Regimen: 500mg, BID for 8 days each drug.

Question 19

What are 2 common antivirals?

Answer 19

Acyclovir and valacyclovir are purine nucleoside analogues and both drugs act against herpes simplex 1 and 2 (IO ulcers and genital herpes, respectively), varicella zoster (shingles and chicken pox), and the Epstein-Barr virus (infectious mononucleosis).
Regimen: 200mg, 5 times a day for 14 days.

Question 20

What are the current guidelines for antibiotic prophylaxis before dental procedures?

Answer 20

Patients with the following are advised to have antibiotic prophylaxis:
* Prosthetic cardiac valves, including transcatheter-implanted prostheses and homografts.
* Prosthetic material used for heart valve repair, such as annuloplasty rings, chords or clips.
* Previous IE.
* Unrepaired cyanotic congenital heart defect (birth defects with oxygen levels lower than normal) or repaired congenital heart defect, with residual shunts or valvular regurgitation at the site adjacent to the site of a prosthetic patch or prosthetic device.
* Cardiac transplant with valve regurgitation due to a structurally abnormal valve.