1
Q
what are pathogens
A
- organisms that can cause human disease
- ex. viruses, bacteria, fungi, unicellular organisms and multicellular organisms
2
Q
how do pathogens infect the body
A
- must bypass body’s defence and find ways to enter body
3
Q
what are the 3 indications for antibiotics in dental practices
A
- treatment of acute odontogenic/orofacial infections
- prophylaxis against infective endocarditis
- prophylaxis for patients at risk for infection because of compromised host defence mechanisms resulting from disease
4
Q
how do we determine the best antibiotic to treat an infection
A
- take a sample of a culture from the infection
- do culture and sensitivity testing with several different antibiotics
- may take days to weeks to identify the bacteria
- viruses may take weeks with culture and sensitivity testing
5
Q
3 drug delivery systems
A
- systemic
- locally applied: topical (oral rinses and oral irrigation)
- controlled-release (fibers; gels, chips, microspheres (powder))
6
Q
what are antibiotics
A
- also called anti-invectives, antibacterial, antimicrobial
- substances produced by living organisms (e.g. microorganisms) that are harmful to other organisms
7
Q
what does bactericidal mean
A
- kills bacteria
8
Q
what does bacteriostatic mean
A
- weakens the bacteria that causes the disease so that your body can attack it and kill it off on its own
9
Q
what are some examples of adverse effects of antibiotics
A
- bacterial resistance to the antibiotic
- superinfections
- gastrointestinal (nausea, vomiting, diarrhea)
- allergic reactions
- photosensitivity
- drug interactions
10
Q
what is antibiotic resistance
A
- bacterial resistance renders the antibiotic ineffective and allows the infection to progress
- the bacteria continue to multiply, grow and survive
11
Q
how can we avoid antibiotic resistance
A
- if you don’t take the antibiotic on time, it will fall below MIC, and you might give the opportunity for resistant bacteria to grow. take it on time for the entire time to kill them all
12
Q
what are superinfections
A
- broad-spectrum antibiotic causes the eradication of microorganisms that are part of the normal flora
- leads to overgrowth of other organisms
- can lead to vaginal candidiasis, pseudomembranous colitis
13
Q
what kind of gastrointestinal problems can people experience from antibiotics
A
- direct irritation or indirectly by upsetting the normal GI flora -> GI distress -> nausea, vomiting, and/or diarrhea
- antibiotic-associated pseudomembranous colitis reported with all antibiotics (overgrowth of a bacteria)
- to avoid GI upset the patient should take antibiotics with Lactobacillus acidophilus (gel caps)
14
Q
what is photosensitivity
A
- exposure to the sun causes an exaggerated sunburn
- should stay away from sun exposure while taking the drug or use sunscreen
- ciprofloxacin (a quinolone) and doxycycline (a tetracycline) will cause photosensitivity
15
Q
when are systemic antibiotics used in periodontal therapy
A
- systemic antibiotics used in conjunction with periodontal debridement and surgery (aggressive periodontitis)
16
Q
when are topical antimicrobial agents used in periodontal therapy
A
- chronic localized periodontitis
17
Q
when might systemic antibiotics be indication in Endodontic therapy
A
- when there is an endodontic lesion with soft tissue swelling and systemic involvement or spread of the infection
18
Q
why do we use antibiotics in implant dentistry
A
- prophylaxis of post surgical infection
19
Q
what kind might peri-implant infections be associated with (signs)
A
- bone loss
- suppuration
- increased pocket depths
20
Q
when are antibiotics not indicated in implant surgery
A
- peri-implant mucositis, which involves soft tissue inflammation around the dental implant
- if necessary, an antimicrobial mouthrinse such as chx gluconate should be used
21
Q
6 major classes of antibiotics used in dentistry
A
- penicillins
- cephalosporins
- macrolides
- tetracyclines
- nitroimidazoles
- lincomycins
22
Q
what is penicillin
A
- bactericidal
- discovered by Sir Alexander Fleming
- administered either orally or parenterally but never topically because of severe allergic reactions
- contain beta-lactam ring in its structure
- lyse cell wall of bacteria - spill its guts and dies (since human cells don’t have cell wall but rather cell membranes, penicillins do not affect our cells)
23
Q
what can render bacteria penicillin resistant
A
- bacterias that produce beta-lactamases
- 95% of staphylococcus aureus produce this enzyme, making penicillins ineffects
- amoxicillin + clavulanic acid (augmentin) prevents the penicillin beta-lactam ring from being destroyed by beta lactamase enzyme
24
Q
when should antibiotics be taken
A
- absorption is greatest when penicillin is taken on an empty stomach
- either 1 hour before eating or 2 hours after eating
- amoxicillin is the exception and can be taken with food
- all penicillins should be taken with a full glass of water to increase absorption from the GI tract
25
which 2 penicillins are the only penicillins used in dentistry for mild to moderate odontogenic infections
- penicillin VK
- amoxicillin (amoxicillin + clavulanic acid)
- amoxicillin is effective against peptostreptococcus which is found in periodontitis sites. amoxicillin is the drug of choice for patients taking prophylaxis to prevent infectious endocarditis
26
how much of the population experiences allergic reactions
- less than 10%
27
can penicillin and a bacteriostatic antibiotic be taken together
- no, space the 2 antibiotics so that they are not given at the same time
28
why do oral contraceptives not work when you're taking penicillin
- estrogen needs bacteria in the gut to break it down before it reabsorbs
- penicillin prevents this, thus estrogen is poorly reabsorbed and not effect
- use alternative birth control
29
when is penicillin VK used in dental treatment
- mild to moderate endodontic, periodontal and odontogenic infections
- treatment of necrotizing ulcerative gingivitis
- reserve amoxicillin for more serious infections (less broad-spectrum antibiotic may be effective)
30
when is clavulin used in dental treatment
- for resistant strains of bacteria (especially periodontal patients refractory to treatment or aggressive forms)
- severe GI upset because of the 'acid'
31
penicillin + bacteriostatic antibiotic
- penicillin should be given a few hours before the bacteriostatic antibiotic
32
what are cephalosporins
- similar beta-lactam ring as penicillins, which is responsible for its antibacterial activity
- bactericidal; kill the bacteria by inhibiting cell wall synthesis by the same mechanism as penicillin
- four generations of semi-synthetic cephalosporins; only a few are given orally
- there is a 10% cross-hypersensitivity reaction with penicillins
33
what are nitroimidazoles
- also called metronidazole
- effective against obligate or strict anaerobic
- found in gingival crevicular fluid in the periodontal pocket (adjunctive treatment of periodontal diseases)
- combined with amoxicillin is good against AA and PG in aggressive periodontitis and nonresponding periodontitis
34
side effects of nitroimidazoles/metronidazole
- GI upset; OK food
- metallic taste; dry mouth; changes in taste
- dark urine
- ok in renal disease
35
drug interactions with nitroimidazoles
- alcohol: disulfiram-like reaction
- headache, nausea, vomiting
- ***watch mouth rinses with alcohol***
- lithium
- anticoagulants (warfarin): increased bleeding
36
what are macrolides
- class of bacteria
- includes erythromycin, azithromycin and clarithromycin
- inhibit the multiplication of bacteria; inhibit protein synthesis within the bacterial cell
- bacteriostatic
- thromycins
- resistance to erythromycin is generally not a problem in short-term therapy
- broader spectrum of action with fewer side effects
37
when is azithromycin used
- in treatment of periodontal disease
38
when is erythromycin NOT used
- in the management of periodontal/endodontic infections
39
when is erythromycin most effective
- in the use against gram + bacteria and some gram - strains
40
what are adverse effects of macrolides
- hepatic (liver) dysfunction
- GI disturbances (eg abdominal pain, diarrhea, nausea, vomiting)
- second-generation macrolides have fewer side effects
41
what drugs may interact with macrolides
- erythromycin and clarithromycin (not azithromycin) are inhibitors of CYP3A4 enzymes in the liver
- theophylline, carbamazepine, cyclosporine, phenytoin, lovastatin, and simvastatin are metabolized by the same enzymes
- thus, when taking erythromycin these drugs will not be metabolized or metabolized slower, resulting in increased blood levels
- taking a bactericidal + bacteriostatic antibiotic together: bactericidal antibiotic may interfere with the action of the bacteriostatic antibiotic, which, to be effective, must have the bacteria multiplying. the tidal drug will kill the bacteria. space the 2 antibiotics
- give bactericidal a few hours before the bacteriostatic for maximal effect
42
what are lincomycins
- clindamycin
- primarily bacteriostatic but can be bactericidal in high doses
- often dental patients will be taking clindamycin for a dental infection such as periodontal abscess or periodontal disease
- dental infections, and refractory (resistant to treatment) periodontitis
43
what are adverse effects of lincomycins
- pseudomembranous colitis, visual disturbances, liver dysfunction
- do not give to patients with Crohn's disease, pseudomembranous enterocolitis, or ulcerative colitis
- watch use in pregnancy
44
what are tetracyclines
- tetracycline hydrochloride
- two semisynthetic analogues of tetracycline doxycycline hyclate and micocycline Hal
- contraindicated in pregnancy or lactation (effect on skeletal growth of the fetus and child)
- contraindicated in children less than 8 years old due to ability to cause permanent discolouration and mottling of teeth
45
what risks are associated with tetracyclines
- risk of superinfection due to candida, take with acidophilus in the form of yogurt or gelcaps
- causes photosensitivity, which may occur within a few minutes to hours to sun exposure
- decreases effectiveness of oral contraceptives
46
what are indications for taking tetracycline
- do not take with milk, other dairy products, iron, magnesium-containing products, antacids
- doxycycline and minocycline is OK with dairy
- wait at least 2 hours before or after taking with lipid-lowering drugs such as colestipol and cholrestyramine
- take with a full glass of water
47
when is tetracycline most commonly prescribed in dental treatment
- tetracycline concentrates higher in the gingival crevicular fluid in the pocket than in the blood
- thus, used in the treatment of aggressive periodontitis
48
what are some drug interactions
- oral contraceptives
| - bactericidal antibiotics
49
what things should we teach our clients regarding taking prescriptions
- take entire prescription for full duration
- wait 30 mins after injections
- avoid intake of coffeinated beverages, citrus fruits, fruit juices for 1 hour before and 2 hours after penicillin
- take cephalosporins with food to decrease GI upset and sulfonamids with food/milk
- drink glass of water with each dose and 2-3 L per day
- antacids, dairy products, iron, baking soda, kaolin-pectin inactivates tetracycline (not within 3 hours)
- oral contraceptives are reduced with sulfanomides, tetracycline, and other antibiotics
- eat active culture yogurt or buttermilk (decrease antibiotic destruction of normal flora)
- avoid sun with sulphonamides and tetracyclines
- antibiotics most effective if taken around the clock rather than just normal waking hours
50
what are topical antibiotics
- local delivery of antimicrobial agents is either by topical application or by controlled-release devices
- distributes the agent or drug to an exposed surface such as the teeth and gingiva
- the most common route for the supra gingival topical delivery of antimicrobial agents is by a mouth rinse, a dentifrice, or an oral irrigator
- subgingical topical delivery of antimicrobial agents is by oral irrigation or the use of controlled-release devices
51
what are oral rinses
- topical antibiotics
- a major requirement for the success of antimicrobial therapy = substantivity
- ability of the drug to absorb or bind to intramural surfaces such as teeth and soft tissues with subsequent release of the drug in its active form
- ex. chx
52
how does chlorahexadine inactive toothpaste
- the positively charge chlorahexadine molecules cause them to bind to the negatively charged molecules in the toothpastes such as fluorides and sodium lauryl sulphate (a detergent) and thus inactivates them
53
what are some side effects of oral rinses
- supra gingival calculus formation
| - tooth and tongue stains
54
what is controlled release delivery
- placed directly into the periodontal pocket
- drugs are designed to release slowly over 24 hours for prolonged drug action
- antimicrobials are delivered into the pocket by fibres, gels, chips, powder, ointments, acrylic strips or collagen films
Pharmacology
flashcards
Decks in class (21)
# Cards
-
Introduction and terminology35
-
Prescription writing12
-
Drug regulation and discovery in canada30
-
Forms and routes22
-
Kinetics and dynamics30
-
Drug reactions25
-
Autonomic drugs60
-
Non opioid analgesics64
-
Opioids46
-
Antibiotics54
-
Antiviral and antifungal agents21
-
Cardiovascular drugs96
-
Medical emergencies21
-
Anaesthetics73
-
Neuro29
-
Antineoplastics19
-
Endocrine48
-
Herbal35
-
Psychotropics44
-
Respiratory55
-
GI Drugs54
