Pharmacology and the dental patient Flashcards
1
Q
What choices do we need to make before administrating a drug?
A
- Do we treat the patient?
- Which drug(s) do we use?
- What dose is appropriate
- Do we need to take any particular precautions?
2
Q
As a dentist what drugs do we need to give patients?
A
1. Analgesics
{Pharmacogenetics}
2. Sedation drugs
3. Antibiotics
4. Local anaesthetics
5. Vasoconstrictors
3
Q
Name the most common type of odontogenic pain
A
Acute pain
4
Q
Name three pain receptors
A
- Bradykinin
- Prostaglandins
- Substance P
5
Q
What are Bradykinin released by?
A
Blood plasma
6
Q
What are Prostaglandins released by?
A
By damaged cells
7
Q
What is substance P released by?
A
nociceptors (sensory neurones)
8
Q
Where do messages from the nociceptors travel to?
A
From the spinal cord to the thalamus
9
Q
What happens to pain impulses at the thalamus?
A
They are distributes to various higher centres
Some also go to the reticular formation (governs alertness) and to the amygdala (a part of the limbic system involved in emotion)
10
Q
What governs alertness?
A
The reticular formation
11
Q
The amygdala is part of what?
A
a part of the limbic system involved in emotion
12
Q
Name the most common type of analgesics used in dentistry
A
Non-opioid analgesics are the most common
13
Q
What are Non-opioid analgesics used to treat?
A
They are drugs used to relieve tooth ache or pain following dental treatment
14
Q
Give examples of non-opioid analgesics
A
- Ibuprofen
- Paracetamol (acetaminophen)
- Aspirin (acetylsalicylic acid)
15
Q
What is an occasional side effect of ibuprofen?
A
Xerostomia that may increase oral plaque and dental caries
16
Q
Give examples of some types of analgesics
A
- Corticosteroids
- Non-opioid analgesics
- Narcotic analgesics
17
Q
Name some Corticosteroids
A
Orabase-HCA
Oracort
Oralone
18
Q
What are Corticosteroids?
A
They are anti-inflammatory medications the are used to relieve discomfort and redness of the mouth
19
Q
Give examples of Narcotic analgesics
A
Codeine Hydrocodone (Vicodin)
20
Q
What are Narcotic analgesics used for?
A
For severe pain conditions
21
Q
What is pharmacogenetics concerned with?
A
Pharmacogenetics is concerned with the identification of genetic variants that affect the responses to medications in patients
22
Q
Why is pharmacogenetics important?
A
As some drugs work more or less effectively in some people than they do for others
23
Q
What is codeine?
A
Codeine is an opiate used to treat mild to moderate degrees of pain.
24
Q
Where is codeines active metabolite?
A
morphine
25
Where is codeine covered into its active metabolite?
In the liver
26
What is the catalysis for the conversion of codeine into morphine?
CYP2D6
27
What is a pro drug?
An inactive drug that must be metabolised to active drugs within the body
28
Give an example of a prodrug?
Codeine
29
What can happen if someone is a poor metaboliser of CYP2D6?
They will experience little to no analgesia from codeine since they lack the enzyme to metabolise the drug.
30
What is the conversion of codeine into morphine called and what type of pathway is it?
O-demethylation conversion
| Represents a minor pathway of codeine metabolism (accounting for less than 10% of codeine clearance)
31
What percentage of the population are poor metabolisers of codeine?
7%-10% Caucasians
3%-6% Mexican Americans
2%-5% African Americans
1% Asians
32
What does it mean of you are a poor metaboliser of codeine?
It means the drug is metabolised very slowly so they may accumulate to toxic concentrations
33
What percentage of the population are intermediate metabolisers of codeine?
10%- 15%
34
What does it mean of you are an intermediate metaboliser of codeine?
It means the patient has a diminished capacity to metabolise drugs
Lower than average dosage may be more sufficient to achieve a therapeutic response
35
What percentage of the population are extensive metabolisers of codeine?
73%- 82%
36
What does it mean of you are a extensive metaboliser of codeine?
This is the typical rate of drug metabolism
37
What percentage of the population are ultra rapid metabolisers of codeine?
```
1%-2% Caucasians
4% North Americans
10% Greeks
10% Portugese
20% Saudia
30% Ethopians
```
38
What does it mean of you are an ultra rapid metaboliser of codeine?
It means the person has a higher than usual rate of drug metabolism
These drugs may not reach therapeutic concentration so the drugs may be ineffective at standard dosages
39
What did Sindrup's investigation in the analgesic efficacy and kinetics of a single oral dose of 75 mg codeine show in respect to pain threshold?
They observed that codeine significantly increased pain thresholds to nocioceptive laser stimuli in Extensive Metabolisers but not in Poor metabolisers
40
What did Sindrup's investigation in the analgesic efficacy and kinetics of a single oral dose of 75 mg codeine show in respect to morphine conc in urine ?
The study also observed that urine collected from Poor metabolisers had undetectable levels of morphine after a dose of codeine was administered.
But when the same dose was given to Extensive Metabolisers, measurable levels of morphine were detectable in their urine
41
The failure of poor metabolisers to convert codeine into morphine is demonstrated by which other molecules?
hydrocodone and oxycodone.
42
Which oral lesions are indicated for antibiotic use?
1. Periodontal abscess
| 2. Acute necrotising ulcerative gingivitis
43
Which antibiotics are most commonly prescribed by dentist?
Penicillins
44
Name some Penicillins used in dentistry
1. Amoxicillin,
2. Penicillin V,
3. Metronidazole
4. Amoxicillin/clavulanate
45
Name the most popular penicillin used in dentistry
Amoxicillin
46
What are Penicillin V, amoxicillin and amoxicillin/clavulanate used to treat?
For the treatment of odontogenic infections
47
What is Metronidazole?
It is a nitroimidazole antibiotic medication
48
What is Metronidazole used to treat?
It is used to treat anaerobic bacteria and protozoa
49
Name some dental infections that Metronidazole is used to treat
Treatment of dental infection of bacterial origin such as:
1. Periapical abscess,
2. Periodontal abscess
3. Acute pericoronitis of impacted
4. Partially erupted teeth
50
What is metronidazole used in conjunction with?
Amoxicillin
51
What should you not take if you are consuming metronidazole?
Alcohol
52
Why should you not consume alcohol if you are taking metronidazole?
```
Is thought to have a disulfiram-like reaction
Side effects include:
Nausea
Vomiting
Flushing of the skin,
Tachycardia
Shortness of breathe
```
53
What is tachycardia?
Accelerated heart rate
54
What is disulfiram used for?
It is used to support the treatment of chronic alcoholism by producing an acute sensitivity to alcohol
55
What characteristics do antibiotic used in short-course antibiotic therapy require?
1. Rapid onset of action
2. Bactericidal activity
3. Lack of propensity to induce resistant mutants
4. Easy penetrability into tissues
5. Activity against non-dividing bacteria
6. Not being affected by adverse infection conditions
7. Administration at an optimal dose
8. optimal dosing regimen
56
What can prolonged courses of antibiotics lead to?
1. Normal resident oral/gut flora being destroyed
2. Selection of resistant strains
3. Colonization by harmful micro-organisms that are not normal residents, e.g. multi-resistant bacteria and yeasts
57
Name some drugs dental patients may already be taking?
1. Antidepressants
2. Nitrates
3. Antihypertensives
4. Opioids
5. Insulin
6. Steroids
7. Beta blockers
8. Monoamine oxidase inhibitors
9. Warfarin
10. Antiplatelet drugs
11. Biphosphonates
58
What do antidepressants block?
They block the action of the neurotransmitter acetylcholine
59
Name a function on acetylcholine
To control the function of the gastrointestinal tract
60
What happens if you block acetylcholine?
It reduces the production of mucous and saliva leading to dry mouth
61
What happens if xerostomia is untreated?
```
Can lead to:
Rampant tooth decay
Periodontal disease
Bad breath
Oral yeast infection
```
62
Why is saliva important in the mouth?
It protects the mouth by neutralising acids and providing lubrication
Saliva also has antibacterial properties
63
What are nitrates used to treat?
They are used to prevent and relieve chest pain (angina) due to coronary artery disease
64
What class of medications do nitrates fall in?
Vasodilators as they widen blood vessels
65
Name the most common type of nitrate
Nitroglycerins
66
What is the most common side effect of nitrates?
A throbbing headache that radiates towards the forehead, the jaw, the throat, the ear, to the back of the head, or, in rare cases, to the neck and to the shoulder
67
What is postural (orthostatic) hypotension?
It is an excessive fall of blood pressure when an upright position is assumed
68
What are some symptoms of postural (orthostatic) hypotension?
```
Faintness
Light-headedness
Dizziness
Confusion
Blurred vison
```
69
What is the most common cause of chronic orthostatic hypotension?
Age related in BP regulation
Vasodilation from antihypertensive drugs
Autonomic dysfunction
70
What promotion of elderly patients suffer from postural hypotension?
a quarter
71
What are Opioid analgesics used to treat?
Used to treat chronic orofacial pain that is refractory to most non-opioid therapy
72
What is a potential risk of undertaking long term opioid therapy?
Potential risk for developing opioid tolerance, dependence or addiction
73
What is the primary oral effect of heroin?
Dental decay
74
What do Heroin addicts, and abusers of other drugs often have?
Poor dental health due to neglect
75
What do people with diabetes have a higher risk of having?
1. Dry mouth
2. Gum inflammation
3. Poor healing of oral tissues
4. Thrush
76
What are thrushes?
yeast thrives on the high levels of sugar in the saliva of people with uncontrolled diabetes
77
What is the most common complication of diabetes therapy in dentistry?
A hypoglycaemic episode
| A severe decline in blood glucose level
78
How can oral infections or dental procedureS affect diabetes?
Can affect food intake in diabetics
79
Why have Synthetic corticosteroids been developed?
Have been developed for their anti-inflammatory and immunomodulatory effects
80
Give an example of Synthetic corticosteroids?
Dexamethasone
81
What risk do patients on steroids present in the dental surgery?
Increased risk of complications because of:
1. Adrenal suppression caused by steroid therapy
2. Disease or condition which required them to take steroids
3. Long-term and other side-effects of steroid therapy
82
What can chronic usage of steroid inhalers increase your risk of getting?
Oral yeast infections and blood blisters
83
Why are beta blockers used?
They are used for their ability to block sympathetic influences on cardiac β1 adrenoreceptors
84
What do patients medicated with non-selective β-blockers have?
A heightened sensitivity to the systemic effects of vasopressors
85
What do patients medicated with non-selective β-blockers have a higher risk of having ?
An acute hypertensive episode if they receive vasopressors contained in local anaesthetics, e.g. epinephrine
86
What are some side effects of beta blockers?
They can decrease hepatic blood flow and/or inhibit hepatic enzymes, resulting in the reduced metabolism of lidocaine (local anaesthetic)
May lead to increased serum levels and, possibly, toxicity of lidocaine
87
What can concomitants administration of beta blockers and lidocaine result in?
Myocardial depression
88
What are monoamine oxidase inhibitors?
They were the first class of drugs used to treat depression
89
What do monoamine oxidase inhibitors do?
They elevate norepinephrine and serotonin levels by limiting their oxidation by the enzyme monoamine oxidase (MAO)
90
What is a major drawback of taking monoamine oxidase inhibitors
Is a potential for drug interactions, many of which precipitate an acute hypertensive crisis
Potential for an interaction between monoamine oxidase inhibitors and vasoconstrictors to cause acute hypertensive crisis
91
What a potential side effect of monoamine oxidase inhibitors?
Can cause acute hypertensive crisis
92
What is warfarin?
Warfarin is an anticoagulant which inhibits synthesis of the vitamin K-dependent coagulation factors II, VII, IX and X
93
What percentage of the UK population take warfarin?
0.5%-1%
94
What is used to express the activity of warfarin?
The international normalised ratio (INR)
95
What is a normal INR number?
1.0
96
What happens as the INR number increases?
The risk of bleeding increases exponentially as the INR rises,e.g. INR=5 indicates a high chance of bleeding
97
When should an INR value be taken and what should it be ideally?
Should be measured within 72 hours prior to the operative procedure
INR value must be below 4.0
98
What are Bisphosphonates used for?
They are used to prevent bone resorption in osteoporosis and bone cancer
99
What are Bisphosphonates used in association with?
Bisphosphonate-associated osteonecrosis of the jaw (BON)
100
What is osteonecrosis of the jaw?
Exposire of dead bone in the jaw
101
What can happen if you suppress bone resorption?
Any damaged bone will be left in situ instead of being resorbed
102
What complications can Bisphosphonates have?
Leads to surgical complication in the form of impaired wound healing following oral or periodontal surgery or endodontic therapy
103
What are some common drugs people can have allergic reactions to?
Additives (sulphites or parabens
| Epinephrine
104
What is Stevens-Johnson syndrome ?
Hypersensitivity complex that affects the skin and the mucous membranes
105
What can begin to form is a patient has Stevens-Johnson syndrome?
Ulcers and other lesions begin to appear in the mucous membranes, almost always in the mouth and lips
106
What can ulcers and other lesions caused by Stevens-Johnson syndrome result in?
They are usually extremely painful and reduce a patients ability to eat or drink
107
Which pain receptor is released by the blood plasma?
Bradykinin
108
Which pain receptor is released by damaged cells?
Prostaglandins
109
Which pain receptor is realised by nociceptors?
Substance P
110
If a patient came in complaining of discomfort and redness of the mouth what type of medicine would you recommend?
Corticosteroids
111
What are nociceptors?
Sensory neurones
112
The reticular formation governs what?
Alertness
113
Which type of drug is most commonly used to relieve tooth ache and pain?
Non-opioid analgesics
114
If a patient comes in with severe pain what could you prescribe them?
Narcotic analgesics
115
What is Amoxicillin used in conjunction with?
metronidazole
116
What word is used to describe a drug that is inactive and must be metabolised to become active?
A prodrug
117
Who would you not prescribe codeine to?
Someone who doesn’t possess the CYP2D6 enzyme as they will not be able to metabolise codeine
118
Name the antibiotics used to treat odontogenic infections
1. Penicillin V,
2. Metronidazole
3. Amoxicillin/clavulanate
119
Which antibiotic is usually used to treat anaerobic bacteria and protozoa and dental infections with bacterial origin?
Metronidazole
120
Patients with chest pain due to coronary artery disease can be given what?
Nitrites
121
Name the syndrome associated with hypersensitivity complex that affects the skin and the mucous membranes?
Stevens-Johnson syndrome
