Anxiolytics and antipsychotics Flashcards
Widely prescribed for anxiety, insomnia and muscle spasm
Benzodiazepines
Food for short tem use and situational anxiety
Benzodiazepines
Can be used with panic disorder due to quick onset
benzodiazepine
Non benzodiazepine
Buspirone (Busbar)
Used for treatment of anxiety disorder, but NOT panic disorder due to its slow onset
Buspirone (Busbar)
Has sedative and muscle relaxant properties
Benzodiazepines
Lacks sedative, skeletal muscle and anti-seizure effect
Buspirone (Busbar)
Not good for pre op anxiety
Buspirone (Busbar)
Does not produce dependance
Buspirone (Busbar)
which has less of a tendency to form tolerance, benzos or barbituates?
Benzos
Which has more tendency for abuse benzos or narcotics?
Narcotics
Benzos mechanism of action
Facilitates the action of GABA by enhancing the affinity for GABA, they DO NOT effect GABA directly
How do GABA receptors work?
GABA is an inhibatory receptor that when activated passes Cl- ions that hyperpolarize the cell and meke the mebrane resistant to excitation
5 pharmacologic effects of Benzodiazepines
- Anxiolysis
- Sedation
- Anterograde Amnesia
- Anticonvulasant action
- Muscle relaxaton at the spinal level
Benzos absorbtion
- highly protein bound
- highly lipid sluable
Benzos Metabolism
Metabolized by CYP 450 system - caution in patients with liver disease
Benzos elimination
Eliminated via the kidneys
RARE CNS effect of Benzos
Paradoxical Excitement
CNS effects of Benzos
- decreased CBF and decreased CMRO2
- Preserves cerebrovascular response to CO2
- Does Not procuce isoelectric EEG
- Does not attenuate ICP response to laryngoscopy
Benzos and Respiratory Effects
- Dose dependant decrease in ventilation
- hypoxemia and hypoventilation enhanced in presence of opioids
- CO2 curve Flattens- does NOT shift
CO2 curves for benzos and narcotics
Benzos - CO2 curve flattens and does not shift
Narcotics- CO2 curve shifts to the right
Benzos Cardiovascular Effects
- At induction doses decreases SVR- so we see a drop in BP
- CO unchanged
Benzos and Laryngoscopy
Even at induction doses Benzos DO NOT attenuated the SNS response to laryngoscopy
Water soluable preperation
Midazolam/Versed
comercially prepared in organic solvents including propylene glycol and benzyl alcohol
Diazepam / Valium
Imidazole ring: pH 3.5 whith an open ring and when it comes to physiologic pH of 7.4 the ring closes speeding the effect of action and increasing lipid solubility
Midazolam/Versed
Viscous: pH 6.6-6.9
Diazepam / Valium
Very highh affininty for Benzo receptor on GABA
Midazolam / Versed
2-3 x the ptency of diazepam
Midazolam / Versed
Painful IV and IM injection
Diazepam / Vallium
90-98% protein bound
Midazolam / Versed
5-10x the potency of Diazepam
Lorazepam / Ativan
Most Potent Amnestic of the Benzos used in anesthetic practice
Lorazepam / Ativan
Has Propylene glycol as solvent
Lorazepam / Ativan
Rapid redistribution and short duration due to its lipid solubility
Midazolam / Versed
Metabolized by the CY P450 System
Midazolam / Versed
Mostly used for premedication, works well in kids
Midazolam / Versed
Midazolam / Versed
Premedication/ Pediatric dose:
0.5 mg/kg PO
Midazolam / Versed
IV sedation / Adults dose
1 -2.5 mg
up to 5 mg
if patient is really anxious or large
Midazolam / Versed
Induction dose
0. 1 - 0.2 mg/kg over 30-60 sec
Midazolam / Versed
Maintinece dose
Incramental or Infusion
Highly lipid soluable and extremly long duration of action
Highly protein bound
Diazepam / Valium
Metabolites are Pharmacologically INACTVE
Lorazepam / Ativan
Lorazipam / Ativan
Elimination 1/2 time
10 - 20 hours
metabolism is less influenced by alterations in hepatic function, age and other drugs
Lorazepam / Ativan
Active metabolite of Diazepam / Valium and its Elimination 1/2 Time
Desmethyldiazepam
41 - 96 hours
Rapidly ablsorbed from GI tract in PO dosages
Diazepam / Valium
Elimination 1/2 Time Diazepam / Valium in Healty volunters
21 - 37 hours
it increases with age
Diazepam / Valium
Premedication / Oral dose
10 - 15 mg
Diazepam / Valium
Premedication / IV Dose
0.2 mg/kg - (it reduces MAC)
Diazepam / Valium
Induction dose
0.5 - 1.0 mg/kg IV
Diazepam / Valium
Anticonvulsant Dose
0.1 mg/kg IV
Why are menzos anticonvulsants?
They inhibit the limbic system in the hippocampus of the brain
Non- selective CNS depression
Barbituates - this is why they are not anticonvulsants
Lorazepam / Ativan
Premedication / PO dose
50 mcg/kg
MAX Dose 4mg
Drug that can cause Neuroleptic Malignant syndrome
Phenothiazines and Thioxanthenes
Phenothiazines and Thioxanthenes mechanism of action
Blockade of dopamine receptors in the basal ganglia and limbic portions of the forebrain
because Phenothiazines and Thioxanthenes interfere with dopamine they…
extrapyramidal side effects
Phenothiazines and Thioxanthenes acheive antiemetic effects by
Blocking the chemoreceptor trigger sone of the medulla
Erratic patterns of absorbtion fter PO administration, but highly lipid soluable and highly protein bound
Phenothiazines and Thioxanthenes
Phenothiazines and Thioxanthenes metabolism
- oxidation in liver with conjugation
- most have inactve metabolites
- T1/2 10-20 hours- longer in elderly
the problem with Phenothiazines and Thioxanthenes side effects is that ______________ due to the blockade of ______________ in the forebrain.
Because of this blockade the brain __________ dopamine receptors and they are _________ sensitive
The effects get worse
dopamine receptors
upregulates
MORE
Extrapyramidal side effecs of Phenothiazines and Thioxanthenes
- Tardive dyskinesia
- Acute dystonic reactions
- Abnormal involutary movements of tongue, face, neck, extremeties.
- Gait issues.
- Skeletal muscle groups involved in breathing and swallowing are involved
- occurs in 20% of patients over 1 year of therapy (elderly and women more susceptable)
- Ususally Perminent (Must stop Treatment)
Tardive Dyskinesia caused by Phenothiazines and Thioxanthenes
- Usually in the first few weeks of therapy
- Acute skeletal muscle rigidity and cramping of face, neck, or back
- Respiratory distress from laryngodyskinesia - laryngospasm that is not life threatening - have hoarsness
- Responds well to diphenhydramine 25- 50mg IV
Acute dystonic reactions caused by Phenothiazines and Thioxanthenes
Phenothiazines and Thioxanthenes cause Cardiovascular effect, what are they, and why do they occur
- Decreases in BP - due to vasomotor reflexes/ peripheral alpha adrenergic blockade
- Relaxant effect on smooth muscle
- NO direct cardiac depression
- NO
- Can see prolonged QT on ECG
Due to the antagonism of _________, ________ and _________ receptors, Phenothiazines and Thioxanthenes causes _________ that develops a tolerance with chronic therapy.
Likewise, the ____________ is decreased and _______________ is acheived by _________ and does not happen at the __________.
- alpha 1
- muscarinic
- histamine
- sedation
- Seizure threshold
- Skeletal muscle relaxation
- CNS deprsseion
- Neuromuscular Junction
- Develops over 28-48 hours
- Hyperthemia
- Hypertonocity of skeletal muslesInstability of autonomic NS
- Fluctuation LOC
Neuroleptic Malignant syndrome caused by Phenothiazines and Thioxanthenes
Distinguishing feature fo Neuroleptic Malignant syndrome from Malignat Hypertermia.
With Neuroleptic malignant syndrome a non-depolarizing muscle relaxant will produce flaccid paralysis whein with Malignant hyperthermia it will not.
When interact with causes sedative effects, Ventilatory depression aand analgesic properties
Phenothiazines and Thioxanthenes and opioids
The ___________ stomp and __________ shuffle refet to some of the _______________ of ____________.
Taialaxine, Thorazine
extrapyrimidal side effects
Phenothiazines and Thioxanthenes
Used to be used in the OR as an anti emetic
Droperodol
ICU delerium and anxiety
Haloperodol (Haladol)
Haloperridol and Droperidol are
Butyrophenones
Butyrophenones promarily have _________ and ___________ side effects.
CNS and Cardiovascular
Does Not cause Amnesia
Noes not have any anticonvulsant activity
Butyrophenomes
name the Butyrophenomes
haloperidol
droperidol
Cause extrapyrimindal effects, cerebral vasoconstrictor
Haloperidol
Droperidol
Haloperidol and Droperidol are _____________ that do not decresese_________.
Cerebral vasoconstrictors
Crerebral metabolic oxygen consumption
can cause dysphoria
Haloperidol
Droperidol
Haloperidol and Droperidol cardiovascular effects include, a minimal decrease in _________ due to ____________, it is a prominit ___________ that protects aginst __________induced dysrhythmias it acts by stabilizing ____________. It can also cause ______________ and _____________ at doses as low as _____________.
blood pressure; alpha blockade; antidysrhythmic; epinepehrine; cardiac cell membranes; prolonged QT interval; torsodes de pointes; 0.625-1.25mg.
Has a black box warning, what is it?
Droperidol
All patiens must get 12 lead prior to administration of droperidol - prolonged QT
Must be monitored for 2-3 hours
Used to be combined with fentanyl to cause a neurolept anesthesia, but it cause a dysphoria
I used to be used often as an antiemetic
Droperidol