L5 Oral Sedation Flashcards
What is the most common route of drug administration?
Oral
7 advantages of oral sedation
- Almost universally accepted
- Ease of administration
- Low cost
- Decreased incidence of adverse effects
- Decreased severity of adverse effects
- No needle fear
- No specialized training
6 disadvantages of oral sedation
- Patient compliance
- Prolonged latent period
- Erratic GI absorption
- Can’t titrate it
- Once taken, unable to readily lighten or deepen
- Prolonged duration of action
What happens if a patient takes too much oral sedation
Can lead to general anesthesia - now you need to know how to get the patient out of this.
Influences on the absorption of drugs
- Lipid solubility
- Bioavailability of the drug
- First pass effect
- Drug inactivation
- Dosage of the drug
- Mucosa surface area
- pH of tissues
- Gastric emptying time
- Presence of food in the stomach
What happens to acidic drugs vs basic drugs in absorption?
Acidic drugs - ex. ASA - freely diffuse across stomach mucosa (pH of 1.4)
Basic drugs - ex. codeine - poorly absorbed in stomach, but absorbed in small intestine (pH 4-6)
Where are most drugs absorbed?
Small intestine, fewer in the stomach - (except alcohol and ASA)
What is the peak effect of most oral drugs?
1 hour
What are the usual gastric emptying times for drug types?
Liquid alone - 90 minutes
Mixed meals - 4 hours
Fatty meals - very slow
What can have an impact on gastric emptying?
Anxiety - can delay emptying by 2x
Extremely fearful patients may be better served without in office oral sedation
What format of dosing has the best absorption
Aqueous solution > oily solution/tab/capsule
Tabs have to be dissolved in stomach first
What affect can the liver have on drugs?
First pass effect
Transformation of drugs into inactive byproducts
- ex. lidocaine
What is bioavailability?
Diff prep of same drug has diff bioavailability
Related to the size of the particles or shape of crystals –> rate of disintegration and dissolution
What is the general duration of oral drugs?
3-4 hours, aka significantly longer than a 1 hour dental appt
What type of patient would benefit from oral sedation?
A patient with slight anxiety that wants to take the edge off - not for patients with severe phobias, they should be treated with something deeper
What does it mean to have titration in oral sedation?
Titration by appt - see how the dose worked in first appt, then “titrate” it by increasing or decreasing for next appt
4 types of oral sedatives
- Sedative hypnotic
- Antianxiety drugs
- Histamine blockers
- Opioid analgesics
What are 3 types of sedatives
Barbituates
Benzo’s
Non-benzo’s
What is the difference btwn a sedative and a hypnotic
Sedative - calming effect
Hypnotic - sleep effect
depends on the dose of the drug
What is a therapeutic index
Toxic Dose: Effective Dose
Closer to 1 = more dangerous
Ethyl alcohol
An old form of sedation - uncommon now
Barbiturates
First truly effective drug
At higher doses - depress medulla –> resp depression
What is the biggest downside for dental use?
Not an analgesic!! doesn’t block pain
Need good anesthesia bc you can get hyper-reaction to noxious stimuli
NOT RECOMMENDED in Dent
What is the long term effect of giving people barbiturates?
Dependence
Tolerance build up
What’s an example of a barbiturate?
Hexobarbital, Phenobarbital
What are the effects of Benzo’s?
Mostly anxiolytic but can also be hypnotic
What are examples of non-bento anxiolygtics/hypnotics
Zolipem (ambien)
Zaleplon (sonata)
still affect GABA receptor compels but diff than benzo’s
How long to non-benzo’s work?
Rapid absorption, short half life
What is the dental use of non-benzo’s?
Pre-op sleep help
Pre-op
Where is chloral hydrate mostly used?
Most common in paediatric dentistry
Side effects of chloral hydrate?
But can produce GI used - has to be diluted with glass of water or milk
Who should chloral hydrate be avoided in?
Coumadin use
Allergic patients
Nursing women
Decrease dose in patients with use of other sedatives
Where do Benzo’s target?
GABA
and parallel glycine in the spinal cord
A CNS effect
What do Benzo’s lead to?
- Reduction in hostile and aggressive behaviour
- Disinhibition
- Paradoxic increase in aggression
- Skeletal muscle relaxant (CNS)
- Anticonvulsant (CNS)
Can lead to respiratory depression!
Where does benzo biotransformation occur?
Liver
Does not stimulate induction of hepatic microsomal enzymes – can be given to those with liver dysfunction
What is the peak plasma level of Benzo’s?
0.5-5 hours
Where do the depressant and anxiolytic effects of Benzo’s occur? where are neuronal discharges inhibited?
Depressant - subcortical level of CNS
Anxiolytic - limbic system and thalamus (emotional area of brain)
Neuronal discharges - amygdala and amygdala-hippocampus nerve transmission
What alters the rate of absorption of Benzo’s in the GI tract?
Usually absorbed readily and reliably from GI tract but the type has an affect on the absorption
What are contraindications to giving Benzo’s?
Allergy Psychoses Acute narrow-angle glaucoma 1st trimester pregnancy Breast feeding Alcohol use, other drug use Elderly pt - reduce dose, titrate
Can Benzo’s be given under 6 months? 6 years?
Not usually
- not diazepam, maybe midazlolam in a very small dose
Not usually recommended under 6 years - except diazepam and midazolam maybe
Drug interactions of Benzo’s?
Alcohol, psychotropic drugs, phenothiazines, opioids, barbiturates, MAO’s, anti-depressants
What is the benefit of triazolam?
Very little residual drowsiness
short half life
Triazolam effects
Drowsiness, headache, dizziness, nervousness
Problem with lorazepam
Would need escort if used
longer half life
Lorazepam effects
Sedation, dizziness, weakness, ataxia
Midazolam main issue
Absorbed more rapid, so onset faster, very short working time, contra-indicated in HF, renal failure, hepatic failure, resp disease
Mild to moderate pre-op anxiety
Diazepam - 5-10 mg
Oxazepam - 15-30 mg
Induction of sleep night before appt
Flurazepam - 30 mg
Trizolam - 0.25-0.5 mg
Can midazolam be given in another way?
Intranasal sedation - peak plasma level of 10 minutes
