Sedative-Hypnotics Flashcards
What is the difference between sedation & hypnosis?
- Sedation : reduced anxiety & minimal CNS depression
- Hypnosis: envouragement & maintenance of sleep, CNS depression is more pronounced & does not refer to the trance-like state
What is the dose-response relationship of Sedative-hypnotic drugs?
- As dose is increased, CNS effects also increase
- CNS effects can increase then maintain its effects at a constant point even if higher doses are given
Why do Benzodiazepines have a greater margin of safety?
Even at higher doses, its CNS effects not necessarily progress further
What is the relationship of sedation dose to assistance in respiration?
As u increased sedation dose, the need for assistance in respiration also increases because of the increase in level of sedation.
What are the different levels of sedation?
- Minimal Sedation: Normal response to verbal stimulation, unaffected airway, CVS, & spontaneous ventilation
- Moderate sedation: Responsiveness is purposeful + responds to verbal & tactile stimulation, no intervention required for airway, adequatew spontaneous ventilation, maintained CVS
- Deep sedation: Responsiveness is purposeful ff repeated or painful stimulation, inervention for airway may be required, inadequate spontaneous ventilation, maintaned CVS
- General anesthesia: unarousable even w/ painful stimulus, airway intervention required, frequently inadequate spontaneous ventilation, CVS may be impaired
Why is it important for px undergoing sedation to fast?
they are at risk for pulmonary aspiration
What are the fasting recommendations for px undergoing sedation?
- Clear water (water, juice w/o pulp) = 2h
- Breast milk = 4h
- Infant formula, Nonhuman milk, Light meal (non fatty) = 6h
- Fried foods, fatty foods or meat = addtl fasting time like 8hr
What are the diff Sedative Hypnotic Drugs?
Benzodiazepines, Barbiturates
Alchohol: ethanol, CHloral hydrate
New drugs: Bispirone (anxiolytic), Suvorexant (Hypnotic), Ramelteon & Tasimelteon (hypnotics)
Others: Clonidine (anti-HTN), antipsychotics, tricyclic depressants, antihistamines
What is the distribution characteristic of Sedative-Hypnotic drugs?
- Lipid soluble = allow entry to CNS
- Rapid distribution= terminates CNS effects
- Can cross placenta
- Expressed in breast milk
- Benzodiazepines = extensive protein-binding
What metabolized Sedative-Hypnotics in the liver?
P450 CYP3A4
Out of all newer hypnotcs, which ones become active metabolites?
Ramelteon
Buspirone
What is the difference betw Benzodiazpines & Barbiturates?
- Benzodiazepines: Enhances inhibitory effects of GABA
- Barbiturates: in lower doses, it enhances the inhibitory effects of GABA, in higher doses, it mimics GABA
What are different drugs that have agonists in the GABA receptor?
Benzodiazepines
Zolpidem, Zaleplon, Eszopiclone bind with a1 subunit
What drug has an antagonist benzodiazepine binding site ligand?
Flumazenil
What drug has an antagonist benzodiazepine binding site ligand?
Flumazenil
What are the organ level effects of sedation?
Euphoria = general feeling of well-being
Anterograde amnesia = cannot recall events happening during drug’s duration ofa ction
What are other organ level effects of sedative-hypnotics?
Hypnosis
Anesthesia
Anticonvulsant effect
Muscle relaxation
Zolpidem, Zaleplon reflexes and internuncial transmission
What is the MOA & 1/2 life of Flumazenil?
competitive antagonism at GABA receptor
0/7-1.3 hr
What should you look out for when giving Flumazenil?
recurrenec of CNS depression abt an hr of giving Flumazenil
What are the AEs of Flumazenil?
- agitation
- confusion
- dizziness
- nausea
- abstinence symptooms in dependent px
What is a new anxiolytic that is for relief of anxiety w/ no marked sedation or euphoria?
Buspirone
What are other important mechanisms of Buspirone?
does not potentiate CNS actions of other drugs
What is the MOA of Buspirone?
partial agonist at 5-HT1A receptor
What should u look out for when giving Buspirone?
- not for panic states, only for general anxiety states
- liver dysfunction can decrease clearance
What drug interaction with Buspirone should be noted?
Buspirone + Monoamine Oxidase inhibitors -> INC BP
What are the purposes of giving Sedative-Hypnotic drugs?
- relief of anxiety
- insomnia
- sedation & amnesia before and during medical and surgical procedures
- tx of epilepsy and seizure states
- component of balanced anesthesia (IV)
- muscle relaxation in specific neuromuscular disorders
- diagnostic aids for tx in psych
What are clinical toxicology of sedative-hypnotic drugs?
- CNS Depression: severe toxicity
- HSN Reaction: skin rashes
- Teratogenicity: Dysmorphic characteristics
- Enhance Porphyrin Synthesis: Barbiturates are C/I in px with acute intermitted porphyria, variegated porphyria
What are the diff alterations in drug response?
- Tolerance: Cross-tolerance exists between diff sedative-hypnitics
- Physiologic dependence: withdrawal symptoms, Cross-dependence is the ability of a substitute similar drug to suppress abstinence symptoms
