Exam 2: Analgesics and Drug Abuse

Define pain

unpleasant sensory and emotional experience associated with tissue damage

protective reflex

How is dental pain transmitted?

peripheral transmission

How is dental pain peripherally transmitted?

noxious stimuli A delta fibers and C fibers are detected by trigeminal nerve V in orofacial region

Describe Afferent Myelinated A Delta Fiber

(conduction rate, stimuli, type of pain)

1. Fast conducting

2. Mechanical stimuli

3. Physiologic pain --> first pain

- Sharp, short duration, localized

- Restorative tooth preparation

(EX: hand on burner, remove it right away bc of A fiber)

Describe Afferent Unmyelinated C Delta Fiber

(conduction rate, stimuli, type of pain)

1. Slow conducting

2. Thermal, mechanical and chemical stimuli

3. Pathologic pain --> second pain, senses

- Dull, aching, long duration

- Periodontal and oral surgery ache

How do we manage dental pain? (2)

Block/ reduce peripheral response

Block/ reduce CNS response

What are options for pain management strategies?

pre-emptive analgesia

post operative analgesia

What is pre-emptive analgesia? Examples?

pre and intra operative that are working on inflammatory mediators

pre ex: take ibuprofen beforehand (pre)

post ex: topical gel for sensitivity, still give them something at the appt (intra)

What is post-operative analgesia? How does it work?

after they are done with treatment, make recs for meds

interfere with peripheral release of mediators

manage CNS pain processing

What are some of the drugs we can use for our patients for pain control? (4)

Local anesthetics

Non-opioid analgesics

Opioid analgesics

Drug combinations

What are the goals of pre-emptive pain management? (2)

1. Reduce peripheral inflammatory pain

2. Modulate neural pain transmission beyond expected duration of local anesthetic (controlling pain management beyond what LA can provide)

patient will feel less before and after surgery

How does preemptive analgesia have clinical value? (3)

1. Delays pain onset

2. Lessens pain severity

3. Reduces use of rescue analgesics (reduce sharp pain, pushing onset further out and body starts to heal before patient feels pain)

Administer prior to or within 2 hrs of tissue injury

What are the benefits of using local anesthetics for pre-emptive analgesia? (bupivacaine)

1. Lasts for a long time

2. Blocks peripheral pain transmission

3. Decreases central neural sensitization

4. Decreases pain in immediate and later post-op periods

5. Coincides with peak pain and prostaglandin release

What are the benefits of using oral analgesics for pre-emptive analgesia? (NSAIDs)

Ibuprofen most frequently studied

1. Blocks inflammatory mediator

production

2. Delays pain onset and lessens severity

3. Opioids generally less effective than NSAIDs

4. Combination of LA and NSAID appears most effective

What are the non-opiods that we use for postoperative analgesia? (3)

1. Salicylates

2. NSAIDs --> propionic acid derivatives, selective COX-2 inhibitors (SCI)

4. Para-aminophenois --> acetaminophen (APAP)

What category is aspirin?

salicylate

How is aspirin available to buy?

regular --> powder

enteric coated --> covered with something to protect stomach/GI

buffered

What are the indications of use for aspirin? (3)

Analgesic (relief from pain), antipyretic (fever) and anti-inflammatory

Mild to moderate pain

Cardiovascular disease treatment and prevention (baby aspirin)

(recommend if 1-6 on pain scale)

What is aspirin's mechanism of action?

irreversible non-selective COX 1,2 acetylation/inhibition

What are the characteristics of aspirin? (4)

1. analgesia, antipyretic

2. analgesic ceiling (more dosage won't increase it's effect)

3. anti platelet --> used bc it thins ur blood, impacts platelets (used in blood clotting)

3. cardiovascular protection and prevention due to blood thinning ability

What is the half life of aspirin?

3 hours

What are the adverse effects of aspirin? (4)

1. Allergy

2. GI nausea, dyspepsia and bleeding (10%)

3. Bleeding

4. Toxicity --> salicylism (toxic dose)

What are the drug interactions of aspirin?

warfarin (coumadin generic name)

blood thinner, aspirin also thins the blood

What are the precautions to take with aspirin? (aka who should you not prescribe it to?)

1. Active GI ulcer

2. Bleeding disorders

3. Frequent alcohol consumption

4. Children/ adolescents with viral infections --> may cause Reye's syndrome

What is the pregnancy risk with aspirin?

risk category C/D

What is the main traditional NSAIDs?

ibuprofen

What are the indications of use for traditional NSAIDs? (4)

1. Analgesic, antipyretic and anti-inflammatory

2. Mild to moderate pain

3. Arthritis

4. Acute dental pain

What is the mechanism of action for traditional NSAIDs?

inhibit cyclooxygenase (COX 1 and II) enzymes or prostaglandin synthase

Selectively inhibit COX 2

What are the dosing facts of traditional NSAIDs? (2)

(efficacy, ceiling effect)

has a ceiling effect

efficacy is > than opioids

What are the adverse experiences in the GI of traditional NSAIDs?

increase risk of GI irritation, inflammation, ulceration, bleeding and perforation

lower ADR rate than opioids

What are the adverse experiences for cardiovascular health of traditional NSAIDs? (3)

1. Increase risk of thrombotic events including stroke and MI

2. Worsening of hypertension with long-term use

3. Increase bleeding risk --> those who use short-term NSAIDs will have higher bleeding tendencies

What are the drug interactions of traditional NSAIDs?

if patient is taking high blood pressure med and NSAIDs, it will lessen antihypertensive effect

ACEIs, β-blockers --> don't take ibuprofen!

if ibuprofen is taken for less than 7 days, should be fine

Describe the allergy to traditional NSAIDs

if allergic, most likely has asthmatics

allergy, asthma, and nasal polyps commonly seen together

What is the pregnancy risk of traditional NSAIDs?

risk category C/D

can breastfeed and use these

How do selective Cox inhibitors use loading doses?? (SCI) How does it compare to NSAIDs?

loading dose to get it going, then lower to maintain it

comparable efficacy effects to NSAIDs

What is the allergy risk of SCIs?

cross-reactivity to aspirin and NSAIDS in aspirin sensitive patients

caution with pre-existing asthma

How is acetaminophen available?

tablet, gel cap, liquid

What are the indications of use for acetaminophen? (4)

1. Mild to moderate pain

2. Antipyretic and analgesic --> equivalent to aspirin (ASA)

3. Insignificant anti-inflammatory

4. No platelet inhibition

What is acetaminophen's mechanism of action?

CNS prostaglandin inhibition

Blocking the nitric oxide pathway

What is the dosing of acetaminophen like?

1. Lessen dose with liver disease or elderly (max 2 mg qd)

2. Ceiling effect

What are the adverse experiences of acetaminophen?

Hepatotoxicity with OD, makes liver toxic with repeated doses

What are the precautions to take when advising acetaminophen?

liver disease and alcoholism

What are pregnancy indications of use of acetaminophen?

drug of choice in pregnancy and nursing

category B

What are the opioids commonly prescribed in dentistry?

Codeine

Hydrocodone

Oxycodone

Combinations

What are the indications for use for narcotic analgesics? (overall)

1. analgesia --> moderate-severe pain

2. antitussive --> anticough

no anti-inflam effect

What is the mechanism of action for narcotic analgesics? (overall)

1. Bind to mu and kappa CNS receptors

2. Increase pain threshold and decrease reaction to pain

What is the dosing like for narcotic analgesics? (5)

1. No ceiling effect

2. Limited by side effects

3. Reduce dosing by ½ in elderly and liver disease

3. Titration reduces risk --> start off with lowest dose to see how it goes

5. Combine with NSAIDs or APAP --> narcotics aren't as effective by themselves, pair well with others

What are the adverse experiences like of narcotic analgesics? What are some examples?

dose related, frequency more common than

NSAIDs

Common AEs -->

Sedation

Xerostomia

Nausea

Constipation

Itching

Histamine release

Respiratory depression --> dose related, primary cause of OD death, elderly are more susceptible

tolerance, dependence and addiction risk

What are the drug interactions of narcotic analgesics?

CNS depressants --> will cause respiratory depression if taken together

What is the allergy risk of narcotic analgesics?

dermatologic --> rash and urticaria

What is the pregnancy risk of narcotic analgesics?

category C/D

if have to prescribe, lowest dose for shortest time

What is the opioid antagonist?

naloxone

binds to receptor and stops mechanism of opioid

What are the indications for use of naloxone?

opioid overdose reversal

How is naloxone given?

nasal or IV

What is naloxone's mechanism of action?

competitive antagonist to mu, kappa, delta CNS receptors

How should we approach prescription of APAP or NSAID?

1. Approach ceiling dose

2. Use a pre-emptive dose

3. Prescribe for duration of maximum pain intensity

4. Administer with "by the clock" schedule

5. Ibuprofen is initial

drug of choise (no contraindications)

6. consider compliance and cost

What should we do if the patient has persisting pain?

1. Consider concurrent dosing of NSAID and APAP (on and off)

2. Add or replace with opioid (combination w/ APAP or NSAID)

3. Dose for analgesia with tolerable AEs --> START LOW!

What is Tylenol #3? (opioid combo)

acetaminophen and codeine

What is Norco? (opioid combo)

acetaminophen and hydrocodone

What is Percocet? (opioid combo)

acetaminophen and oxycodone

What is Percodan? (opioid combo)

aspirin and oxycodone

What do we need to tell our patients when taking non-opioid and opioid analgesics?

1. Inform patient of correct and maximum dosing

2. Warn patient about side effects such as bleeding, gastritis and sedation

3. Warn patient about supplementing with OTC drugs

How do practitioners play a role in controlling substance?

Authorized to prescribe by state

registered with DEA or exempt from registration

How does the DEA play a role in controlling substance?

focus is prevention of diversion to illicit market (not bound by law)

no claim of expertise in medical prescribing decisions

Which substances are controlled? Who enforces them?

Schedules I through V

DEA enforced

Describe Schedule 1 drugs

(abuse and use)

1. High potential for abuse

2. Non-research use is illegal under federal law

3. Not currently accepted medical use (changes state to state --> mj use)

4. Lack of accepted safety for use under medical supervision

What are examples of Schedule 1 drugs?

LSD, heroin

Describe Schedule 2 drugs

(abuse, use)

1. High potential for abuse, highly regulated

2. Accepted medical use

3. If abused, severely psychological or physical dependence

What are examples of Schedule 2 drugs?

Morphine

Oxycodone

Percodan

Hydrocodone

Hydromorphone

What are the components of Schedule 2 prescription requirements?

1. All information as per non-scheduled drug prescription

2. Some states require multi-copy forms - should be paper copy with written signature

3. Prescriber signature and date required

4. No refills

When can a Schedule 2 drug have oral or fax authorization?

Emergencies

No alternative treatment

Not reasonable to provide written Rx

Quantity sufficient for emergency period

Describe Schedule 3 drugs

(abuse, dispensing, refills)

1. less potential for abuse --> moderate or low physical dependence or high psychological dependence

2. dispensed in office but carefully supervised

3. No refills

What is an example of Schedule 3 drugs?

codeine

What are the components of Schedule 3 prescription requirements?

1. Written, faxed, or oral prescriptions

2. Must have signature

3. E-filing and signature in progress

4. DEA number required

Describe Schedule 4 drugs

(abuse, dispensing, no refills)

1. Lower abuse potential --> limited physical dependence or psychological dependence

2. dispensed in office

3. no refills

What are some examples of Schedule 4 drugs?

Benzodiazepines -->

Diazepam (Valium®)

Triazolam (Halcion®)

What are the Schedule 4 prescription requirements?

1. Written, faxed, or oral prescriptions

2. Must have signature

3. E-filing and signature in progress

2. DEA number required

Describe Schedule 5 drugs

(abuse, refill)

1. Low potential for abuse --> limited physical dependence of psychological dependencies

2. refill once up to 1 year from date of issue of prescription

What are some examples of Schedule 5 drugs?

antitussive cough medicine with codeine

Which schedule drugs need to report an electronic submission?

2, 3, 4

What should providers watch for for drug seeking behavior?

1. Evasive about physician and medical history

2. Patient unable to reach dentist

3. Asks for specific drugs by name

4. Claims allergy or lack of efficacy with specific drugs

5. Lost prescription

6. Requests higher doses or quantities

7. Call late in the day or near weekend

8. Identify doctor shoppers

9. Identify inappropriate prescribing by variety of providers

Define addiction

chronic, relapsing brain disorder defined by compulsive drug-seeking behavior regardless of consequences

most severe for of substance use disorder

Define substance use disorder

recurrent use of substances that causes clinical (medical/dental issues) and functionally significant impairment (can't make it to work/ events) in responsibilities

Define physical/physiologic dependence

substances are necessary for functioning and lack of use results in withdrawal

Define psychological dependence

withdrawal of substances impact them emotionally (anger, crying) and drug-seeking behavior

there is no physiological dependence

cravings

usually developed first before physiologic dependence

Define tolerance

repeated doses require a larger dose to produce a similar effect

How is alcohol absorbed? (CNS depressents)

rapidly in GI tract

What does over use and consumption of alcohol result in?

withdrawal

long term effects to liver, GI tract, diabetes

What are the treatments of alcholoism?

AA

disulfiram, naltrexone, acamprosate (meds)

What are the dental considerations for alcohol?

Poor oral hygiene

Glossitis

Loss of tongue papillae

Angular Cheilitis

Candida infection

Slow healing

What is nitrous oxide? Who is it abused by? (CNS depressant)

incomplete general anesthetics, works very fast

abused by dental professionals

What kind of dependence is nitrous oxide?

psychological

What are the ADR of nitrous oxide?

Impairment

dizziness, headache, tachycardia (increased heart rate), syncope (brief loss of unconsciousness), hypotension

Hallucinations

Infertility and mental dysfunction

Death

Define myeloneuropathy

sign of nitrous oxide

loss of finger dexterity

numbness of extremities

loss of position and vibration sensation (clumsy, loss of proprioception)

What are the opioids that are prescribed? (CNS depressents)

morphine, hydromorphone, Demerol, oxycodone, hydrocodone

Describe the characteristics of opiods

Highly addictive

Often times laced with fentanyl

Tolerance can develop

Overdose is possible and can result in death

What medication is used for overdose of opioids?

naloxone (Narcan)

What medication is used for treatment of opioid addiction?

naltrexone (opioid antagonist)

What is methadone prescribed for?

used to help with physiological dependence

maintenance for recovering from addiction/plan for treatment

prescribed in small dose

What are the drug groups of sedative-hypnotics?

barbiturates

alcohol

meprobamate

benzodiazepines (chlordiazepoxide and diazepam (Valium)

nitrous oxide