Pharm: Chapter 10+11
long acting barbiturates:
phenobarbital (Luminal) used for treatment of epilepsy
oversedation:
- Persistently closes mouth - Persistent mouth breathing - Nausea/uncomfortable - Laughing/ crying - No response or sluggish response to verbal commands - Sudden jerking movements- Incoherent vocabulary- Uncooperative - talking/moving
what to inform patient:
- eat light meal before appointment do not fast -if a large meal is eaten NOT 3 hours prior to dental appointment -will be able to drive home
document:
-Date, BP/pulse before and after tx, consent signed -Amount of N2O + O2 given and for how long -100% O2 for how long at end of appointment - patient's response
end of appointment:
-Discontinue nitrous and return to 100% oxygen for 5 minutes. Can administer longer if patient feels dizzy -If 100% O2 not given to patient for at least 5 minutes possible Diffuse Hypoxia
General Anesthesia Stage III: Surgical anesthesia
-Planes I and II •Return of regular respiratory movements •Muscle relaxation •Normal heart and pulse rates -Plane III, progressing to plane IV •Intercostal muscle paralysis (diaphragmatic breathing remains) •Absence of all reflexes •Extreme muscle flaccidity
Propofol IV:
-Propofol is an IV anesthetic that produces an onset of anesthesia in 30 seconds and a duration of action of about 5 minutes. Patients "feel better" and begin ambulation sooner than with other agents -Can cause cardiovascular and respiratory depression •(Michael Jackson) Metabolized in the liver
ideal sedation:
-Reduced fear & anxiety - Fully conscious- Reduced eye movement Eyes become glassy - Body warmth- Tingling of extremities Toes and fingers- Feeling of vibrations- Feeling of euphoria
general anesthesia stage 1: analgesia
-Stage used in dental offices -The patient is still conscious and can respond Reduced pain sensation -Reflexes are present; respiration remains regular -N2O in dental office -Some amnesia may be evident -The end of stage I is marked by loss of consciousness
Stage IV respiratory or medulla paralysis:
Cessation of respiration and circulatory failure Pupils are maximally dilated Blood pressure falls rapidly If this stage is not reversed immediately, the patient will die Respiration must be artificially maintained
what is N20 + O2 used for:
-To decrease patients recall of severity of anxiety and/or pain associated with a visit to the dental office -Behavioral enhancement, especially in children -Intolerance for long appointments -To increase patient comfort during local anesthetic injections -To increase patient comfort or to decrease a hyperactive gag reflex during radiographic exposure (NOTE: ONLY if X-ray unit is in same operatory)
how to seat patient:
1. assess medical history 2. BP and pulse taken 3. explain procedure 4. assess for proper hoods/ attach tubing 5. inform consent signed (verbal consent in office setting)
how to prepare equipment:
1. before patient is seated all tanks are on 2. no leaks (should be preformed weekly) 3. attach scavenger system to HVE 4. several hoods are present for sizing
anti-anxiety agents sedative and hypnotic agents:
1. benzodiazepines 2. anxiolytics
two major classes of CNS depressants:
1. benzodiazepines 2. barbiturates
Nonbenzodiazepines-nonbarbiturates sedative-hypnotics:
1. buspirone 2. anxiousective
goals of surgical anesthesia:
1. good patient control 2. adequate muscle relaxation 3. pain relief
what is nitrous oxide chemical and physical properties?
1. of all inhalation anesthetics, safest and most commonly used 2. colorless, odorless gas with a faint sweet smell 3. non-irritating and non allergenic 4. non-flammable 5. bottled as liquid, returns to gaseous form
patient care during:
1. once you begin you CANNOT leave patient 2. place patient supine 3. start scavenger system 4. find patients tidal volume 5. administer 100% o2 for 1 minute 6. remember to always talk calmly with patient •Each appointment may be a different amount •NEVER immediately go to the average 35% or jump to the last amount used by the same patient 7.Watch bag (often) - proper inflation and deflation 8.Minimize patient conversations But ask patient occasional questions to ck on sedation level
barbiturates adverse reaction:
Exaggerated sedative or hypnotic reaction Stimulation Fetal harm Can be lethal Coughing and laryngospasm Depress liver and kidney function Reduce gastrointestinal motility Lower body temperature Acute poisoning
how long does it take to remove nitrous oxide:
3-5 minutes
what is nitrous oxide onset time:
30-60 seconds rapid onset due to its absorption from pulmonary alveoli into the circulatory system
levels of anesthesia Flaggs approach: maintenance
: begins with patient at depth of anesthesia sufficient to allow surgical manipulation; continues until completion of procedures
zolpidem (Ambien and Ambien CR) (used to treat insomnia only) issues reported:
Amnesia, anxiety and depression worsen Drowsy driving or "sleep driving" Binge eating while sleeping Solution: Doses reduce for both male/female patients to reduce daytime drowsiness
the ugly of barbiturates:
Associated with complete cardiovascular and respiratory depression with overdose
Benzodiazepines dental relevance:
Avoid additive CNS depression Avoid in addicts or women who could be pregnant Document accurately in patient record Use glucuronidated type in elderly patients or patients on cimetidine (safest choice Lorazepam) Warn patient about sedation and amnesia Match onset and duration Have pt arrange transportation Provide written postoperative instructions Monitor vitals
Buspar is what drug category:
B- can be used for pregnancy -adverse effects include: nervousness insomia
the good of barbiturates:
Barbiturates are still used as anticonvulsants and to induce general anesthesia
what system does nitrous oxide depress:
CNS depression and euphoria with little effect on respiration (analgesia and amnesia)
Anesthetic agents adverse reactions:
Cardiovascular system Arrhythmias = ventricular fibrillation with halogenated hydrocarbons. Blood pressure Respiratory depression Explosions/flammability Teratogenic (male or female exposure) Hepatotoxicity (repeated exposure) Other: Headache, fatigue, irritability, addiction
adverse reactions of nitrous/ oxygen:
Complications have been the result of misuse or faulty installation of equipment Nitrous oxide concentration should be automatically limited and have a fail-safe system that shuts off automatically if the oxygen runs out Nausea and vomiting Chronic abuse -Reduces B12 -Megaloblastic anemia = chronic abuse of N2O
Centrally Acting Muscle Relaxants:
Exert their effects on the CNS to produce skeletal muscle relaxation carisoprodol (Soma) chlorzoxazone (Parafon Forte DSC) methocarbamol (Robaxin) orphenadrine (Norflex) cyclobenzaprine (Flexeril) -strongest centrally acting skeletal muscle relaxer diazepam (Valium) Use: symptomatic relief of temporomandibular joint disorder Known side effect: Xerostomia
inhalation agents:
Gases: Nitrous oxide Volatile liquids Ether, halogenated hydrocarbons (including trichloroethene, halothane, and chloroform)
Benzodiazepines pharmacologic effect:
Helps and Hinders Behavioral effects -Anti-anxiety and panic attack reduction in low doses •Short-term treatment -Drowsiness and sleepiness at high doses -Treats neurosis like obsessive-compulsive disorders Acute treatment of seizures/ Has antiseizure effects Muscle relaxants and Controls of muscle spasms (MS) Conscious sedation, general anesthesia, or during/prior to surgery Insomnia management (sleep disorders), convulsions, and other acute stress reactions Treatment of alcoholism
all of the following habits should be followed to minimize insomnia with melatonin:
Light snack (warm milk) at bedtime Awake at 6 AM even if sleep only began at 5AM. Remaining in bed no longer than 20 minutes without sleeping No smoking within 8 hours of bedtime
______is an intravenously (IV) administered benzodiazepine that is used for conscious sedation in oral health care.
Midazolam (Versed)
Blue color of the tank indictes:
N20= nitrous oxide
what is diffusion hypoxia and how can it be avoided?
N2o leaves body rapidly and is replaced by n2 not enough o2 is in system as n2o is heavier then o2 patient should get 100% oxygen for 5 minutes following discontinuation of n20
Benzodiazepines important concepts:
NO ANALGESIC EFFECT (No effect on pain) Produces Xerostomia Useful in the treatment of TMD Reverses status epilepticus and seizures associated with local anesthesia overdose Smoking reduces effectiveness If dental patient is Premedicated with a Benzodiazepine patient NEEDS to have a driver to and from the office Associated with anterograde amnesia Disorientation, confusion and aggressive behavior reported especially in the elderly
Melatonin:
Naturally occurring hormone made by the pineal gland that is relaxed as the day ends and darkness takes over Can be manufactured synthetically Used to treat insomnia Can cause daytime sedation, morning grogginess, depression, headache, stomach cramps, and irritability
What are barbiturates?
Neurotransmitter GABA) -Principal effect = CNS depressant Longest-acting •phenobarbital (Luminal) •butabarbital (Butisol) •secobarbital (Seconal Sodium) •thiopental sodium (Pentothal) Ultrashort-acting Mechanism of action is less specific than benzodiazepines
Green color of the tank indicates:
O2= oxygen
Buspirone:
Onset of action: 1 week May take 2-4 weeks to see antianxiety effects patient may need a sedating drug if patient is within 2-4 weeks of starting bupar.. The patient may need a benzodiazepine for situational anxiety for the dental treatment
Intravenous agents:
Opioids Morphine Ultrashort-acting barbiturates Methohexital (Brevital) Thiopental sodium (Pentothal) Benzodiazepines Valium Versed Barbiturates = Pentothal Dissociative = Ketamine
barbiturates absolute contraindication: Porphyria
Patients with intermittent porphyria or a positive family history of porphyria Barbiturates can stimulate and increase the synthesis of porphyrins, which are already at an excessive level in this disease
Benzodiazepines can be abused:
Physical dependence and tolerance have been documented One advantage of benzodiazepines over barbiturates is their wider therapeutic index (TI), or range of safe dose. Combining benzodiazepines with other CNS depressants (ie alcohol) reduces safety resulting in coma respiratory depression hypotension hypothermia
advantages of nitrous/ oxygen:
Rapid onset: Under 5 minutes Easy administration: No injection required Close control: Percentage of nitrous oxide easily adjusted Rapid recovery Acceptability for children Relaxed dental team
nitrous oxide: contraindications and dental uses:
Respiratory obstruction/COPD Hepatitis, infections, HIV Emotional instability (manic/depression) Patient doesn't understand procedure Pregnancy considerations 1st trimester -But beneficial during birth History of substance Abuse Pt does not want N2O
Melatonin Receptor Agonist: ramelteon (Rozerem):
Treatment of insomnia characterized by difficulty falling asleep ramelteon is a melatonin receptor agonist not a controlled substance There have been no reports of tolerance, rebound insomnia, or withdrawal effects. The long-term safety of ramelteon is unknown.
why choose benzodiazepines:
WHAT? -Acts as agonists at the benzodiazepine receptor site, thereby reducing the symptoms of anxiety. -Onset of action related to lipid solubility •Storage in adipose tissue prolongs action DISPENSED? -Available as tablets, capsules, oral solution, rectal gel, and injectable form SAFETY? -Crosses the blood-brain and placental barriers produces an effect on the CNS and the fetus (Alprazolam (Xanax) Class D pregnancy category) Metabolized? Ø Liver ****
barbiturates pharmacokinetics:
Well absorbed orally and rectally Injectable solutions are irritating (use IV NOT IM) Potent liver enzyme stimulators... Short- and intermediate-acting barbiturates are rapidly and almost completely metabolized by the liver Long-acting barbiturates are largely excreted through the kidneys as a free drug
Short-intermediate acting barbiturates:
butabarbital (Butisol) secobarbital (Seconal Sodium) little medical use; replaced by benzodiazepines
Levels of anesthesia Flaggs approach: Induction:
all preparation and medication up until operation begins
Hypnotic CNS depressants:
ambien luminal butabarbital secobarbital
what is general anesthetics:
are a (CNS) depressants. They produce a reversible loss of consciousness and insensitivity to painful stimuli. •Techniques use balanced anesthesia using a combination of drugs to minimize adverse reactions. • •The patient must be monitored constantly for respiratory depression and loss of protective reflexes associated with general anesthesia. • •Oral and maxillofacial surgeons have used general anesthetic drugs for many years with an excellent safety record.
the bad of barbiturates:
associated with high rate of abuse
levels of anesthesia Flaggs approach: recovery
begins with termination of surgical procedure until patient is fully responsive
how is pulmonary ventilation monitored?
by watching reservoir bag inflate and deflate with patients breathing-bag should be 2/3 full at all times
where does nitrous oxide enter and excrete:
enters= lungs excrete= lungs
diffuse hypoxia phenomenon:
if the mask is removed without the 5 minute 100% oxygen recovery period
Benzodiazepines IV:
include diazepam (Valium) and midazolam (Versed). An advantage of Versed is that it is water soluble and does not need a solvent for solution so thrombophlebitis, a major side effect of diazepam, can be avoided. Other advantages include that it has a shorter duration of action and produces more amnesia than does diazepam.
what is notorious oxide commonly known as?
laughing gas or nitrous
what is the solubility in blood and tissue for nitrous:
low, which allows for equilibrium between inhaled nitrous oxide-oxygen mixture in blood to be reached within minutes
is nitrous a complete anestetic:
not a complete anesthetic, because of its low potency, it is a good analgesic and anxiety reliever, but weak general anesthetic when used alone.
why is a scavenging system important?
removes excess n2o, exhaled from operatory
Barbiturates:
the original sedative-hypnotic agents, are chemically related to each other and have similar pharmacologic effects to benzodiazepams...They differ from each other mainly in their onset and duration of action. •DUE TO That they're Associated with a high rate of abuse resulting in Benzodiazepines having almost completely replaced barbiturates for treating anxiety and insomnia.
Ultrashort acting barbiturates:
thiopental sodium (Pentothal) IV used intravenously for induction of general anesthesia Onset: Immediate Duration: Minutes
how does the RDH monitor patients level of conciousness?
verbal stimulation
Nonbenzodiazepine-Benzodiazepine Receptor Agonists used to treat insomnia only:
zolpidem (Ambien and Ambien CR) -may be used in dentistry if the patient is having difficulty falling asleep the night before a dental appointment. zaleplon (Sonata) -is a rapid-acting hypnotic that is less potent and has a shorter duration of action than zolpidem. It can cause anterograde amnesia. eszopiclone (Lunesta) -may be used in dentistry if the patient is having difficulty falling asleep the night before a dental appointment.
barbiturates reduce drug eddects:
ØAcetaminophen Øβ-Blocker ØBirth control pills ØChlorpromazine ØDoxycycline ØEstrogens ØGriseofulvin ØPhenytoin ØQuinidine ØSteroids ØTricyclic antidepressants ØWarfarin
barbiturates enchance drug effects:
ØDisulfiram ØPropoxyphene ØPhenytoin Enhanced or additive CNS depressant effect ØAlcohol ØCNS depressants ØOpioid analgesics
what is benzoiazepines:
•Act on the CNS by enhancing the inhibitory neurotransmitter GABA ( gamma- amino butyric acid which has a calming effect.. Theres a lot of information on this page...so really look at this one First notice The zzzz's in the generic name....sleep producing = sedative agents along with being hypnotic (producing amnesia lorazepam (Ativan) safest for elderly/ liver disease alprazolam (Xanax) Pregnancy Category Class D : •Class D categories include Pregnancy and lactation considerations... Cleft palate, central nervous system malformations/encephalopathy, and permanent functional disturbances occurred in animal models at maternally toxic doses. Neonatal flaccidity (Floppy infant syndrome) Increased risk of congenital malformations triazolam (Halcion) (AMNESIA) midazolam (Versed) used for IV conscious sedation in oral health care.
ambien CR:
•CR (continued release) has been reported to promote behavioral and emotional changes such as decreased inhibition similar to those taking other CNS depressants such as alcohol...sleep driving,, binge eating while sleeping... driving impaired...(many accidents have occurred) Solution to problem to reduce both the immediate release and the CR doses fot BOTH Men and Women to reduce daytime drowsiness...
barbiturates chronic long-term use:
•Chronic use of barbiturates can lead to physical and psychological dependence. The addict becomes progressively depressed and is unable to function. •Tolerance develops to most effects of barbiturates but not to the lethal dose. Therefore, a larger and larger dose must be used to produce an effect, and this dose can approximate the lethal dose. •Cross-tolerance occurs among barbiturates and between the barbiturates and nonbarbiturate sedative-hypnotic agents.
Butabarbital:
•Common brands: Butisol •Description Sedative It can treat trouble falling asleep (insomnia). It can also make patients feel sleepy before surgery or a medical procedure.
secobarbital:
•Common brands: Seconal Sodium •Description •Sedative It can treat trouble falling asleep (insomnia). It can also make patients sleepy before surgery or medical procedures.
anxioselective:
•Its mechanism of action is unknown, but it is believed to be related to interactions with neurotransmitters in the CNS. •The pharmacologic effect of buspirone is called anxioselective because of its selective anxiolytic action without hypnotic, anticonvulsant, or muscle-relaxant properties. It provides much less CNS depression than other sedative-hypnotic agents and does not affect driving skills. It does not produce tolerance or dependence. It does not appear to be addicting and there is not withdrawal syndrome. However, most patients prefer the benzodiazepines.
Benzodiazepines extra information:
•Rarely normal Doses of diazepam have been reported to produce respiratory depression if it happens These respiratory effects are more common in elderly patients and can be exacerbated by opioids or alcohol. (meaning pulse rate can drop) •BUT CAN OCCUR IN OVERSEDATION If patient is unresponsive DDS could use: •Romazicon (flumazenil) •a Benzodiazepine antagonist (given IV) •Normal rate of respiration 12-20 breaths per minute
general anesthesia stage II: Delirium or excitement
•Stage begins with loss of consciousness and is associated with involuntary movement and excitement •Respiration becomes irregular, and muscle tone increases •Sympathetic stimulation produces tachycardia, mydriasis, and hypertension •Emesis (vomiting) and incontinence (defecation) can occur
barbiturates pharmacologic effect:
•The principal effects of the barbiturates are on the CNS. With normal doses, relaxation occurs. With larger doses, inhibitory fibers of the CNS are depressed, resulting in disinhibition and euphoria. When higher doses are administered, hypnosis can be produced. Even higher doses can result in anesthesia, with respiratory and cardiovascular depression and finally arrest. •Barbiturates have no significant analgesic effect. Even doses that produce general anesthesia do not block the reflex response to pain. Patients in pain may become agitated and even delirious if barbiturates are administered without analgesic agents. •Barbiturates have anticonvulsant action. Long-acting agents such as phenobarbital are used to treat epilepsy.
why do we need to diffuse hypoxia phenomenon:
•The rapid outward flow of carbon dioxide, a stimulant to respiratory drive, could decrease ventilation with resultant hypoxia. The patient may complain of headache, nausea, syncope or other side effects •Easy fix •place back on oxygen 100%
use of untrashort-acting IV barbiturates:
•These barbiturates are combined with the nitrous oxide-oxygen combination, which are then administered along with a volatile inhalation anesthetic. •If local anesthetic blocks are administered before oral surgery procedures, the depth of general anesthesia can be lighter.
opioid IV:
•are an adjunctive drug to general anesthesia in preanesthetic medication. They provide analgesia during and after surgery. The major disadvantage of the opioids is prolonged respiratory depression.
what is anxiolytics:
•buspirone (BuSpar) is classified as azapirones, which have both antidepressant and anti-anxiety (BuSpar is no loner prescribed in the US but generics are available) Because it's a FDA pregnancy B category it is safe to use during pregnancy is an agent is necessar •MOA= mechanism of action •So if asked which (pr·en·tr·uhl) parenteral benzodiazepines seems to have the greatest likelihood to produce amnesia? •Diazepam (Valium) • Midazolam (Versed) • Triazolam (Halcion) Correct • Eszopiclone (Lunesta)
Luminal (phenobarbital):
•is a barbiturate (bar-BIT-chur-ate). Phenobarbital slows the activity of your brain and nervous system. Phenobarbital is MOSTLY prescribed to treat or prevent seizures. Phenobarbital is also used short-term as a sedative to help you relax. Pentothal is ultra short acting to
Etomidate IV:
•is a short-acting intravenous anesthetic agent that is used for conscious sedation and as part of the sequence of rapid general anesthesia induction. It has a rapid onset of action and has a safe cardiovascular profile. It can cause adrenal suppression, especially after repeated dosing.
Katamine (kETALAR):
•is chemically related to PCP, a hallucinogen. The anesthetic state ketamine produces has been given the name dissociative anesthesia because ketamine appears to disrupt association pathways in the brain. The patient appears to be catatonic and has amnesia. It produces analgesia without actual loss of consciousness. It is the only anesthetic that may be given intravenously or intramuscularly, with a rapid (1 to 2 minutes) onset of action. Ketamine is primarily used by oral surgeons, and it can produce excessive salivation, so atropine is a necessary premedication.
anti-anxiety agents value of relaxation:
•patient includes a more productive dental appointment, and the patient, dentist, and dental hygienist all benefit. •Often, patient anxiety is sufficiently reduced by a calm, patient, confident, and understanding attitude on the part of the dental health care team.
Benzodiazepine drug interactions:
•will interact in an additive fashion with other CNS depressants, notably alcohol, barbiturates, anticonvulsants, •Enzyme inducers may increase their metabolism, and enzyme stimulators may decrease their metabolism. • •Drugs such as cimetidine, disulfiram, isoniazid, and omeprazole may increase the effects of benzodiazepines. • •Selective serotonin reuptake inhibitors have greatly increased diazepam levels by altering its clearance. •Benzodiazepines may reduce the effectiveness of levodopa, and parkinsonis it to get worse I •Benzodiazepines may increase the effect of digoxin, phenytoin, and probenecid.