CNS Anxiolytics, Sedative and Hypnotic Drugs - Kelly 4 Flashcards Preview

Pharmacology 3001 > CNS Anxiolytics, Sedative and Hypnotic Drugs - Kelly 4 > Flashcards

Flashcards in CNS Anxiolytics, Sedative and Hypnotic Drugs - Kelly 4 Deck (20)
1

Sedative drug

Reduce person's response to external stimuli
Reduces anxiety and has calming effect with minimal depression of motor or mental functions

2

Hypnotic drug

Cause drowsiness and sleep-like state

3

Anxiety

Changes in mood, physiological arousal and increased perceptual acuity
Tachycardia, sweating, trembling, palpitations, unpleasant state of tension, apprehension, uneasiness
Disorders involving anxiety and sleep are the most common mental disturbances

4

Classes of sedative-hypnotics

Benzodiazepines
Barbiturates
Sedative-autonomic (Beta-blockers, clonidine, TCA's, antipsychotics - short or long and action based on need/intention)
All anxiolytic drugs also cause sedation (based on dose)

5

Ceiling effect of benzodiazepines

Not found in barbiturates, causing higher mortality and coma

6

Benzodiazepines pharmacokinetics

Absorbed in gut
Rate where BZ crosses CSF depends on protein binding, lipid solubility and ionization constant
Usually easily cross BBB and placental barrier
Extensively metabolized by the hepatic microsomal metabolizing system to active compounds
Excreted in urine
Psychological and physiological dependence with prolonger use
Tolerance
Additive manner with alcohol, barbiturates and anticonvulsants
Smokers need higher dose of drug
SSRI increase levels

7

Long acting BZ

Diazepam, chlordiazepoxide, flurazepam
Form active metabolites with long half-life
Drowsy in morning

8

Intermediate acting BZ

Alprazolam, lorazepam, temazepam

9

Short acting BZ

Oxazepam, triazolam

10

Adverse reactions of BZ

Drowsiness and confusion, ataxia and cognitive impairment at higher doses
Abrupt discontinuation results in confusion, anxiety, agitation, restlessness, insomnia and tension
Onset of withdrawal relates to half life of BZ

11

BZ pharmacodynamics

Allosteric modulator
Increase GABA binding to channel, inducing Cl influx

12

Therapeutic uses of BZ

Anxiety disorders
Muscular disorders (spasticity from degenerative disorders)
Seizures (chronic treatment of epilepsy)
Acute treatment of alcohol withdrawal
Sleep disorders (shorter duration BZ)

13

Barbiturates

Well absorbed orally, distributed widely throughout body
Metabolized in liver into inactive metabolites that are excreted into urine
Mainly replaced by BZ
CNS depressants, which is additive with alcohol and opioids
No significant analgesic affects
Anticonvulsant effects

14

Barbiturate pharmacodynamics

In high doses, can activate GABA receptor
Allosteric modifier

15

Therapeutic uses of barbiturates

Anesthesia
Anticonvulsant (phenobarbital used in long term management of tonic-clonic seizure)
Anxiety (mostly replaced by BZ)

16

Thiopental

Ultra-short acting
Barbiturate used IVE to induce surgical anesthesia

17

Busiprone

5-HT1A receptors
Also has affinity for DA2 receptors
Treatment of generalized anxiety disorders, little sedation, no anti-convulsant or muscle-relaxant properties

18

Zolpidem

Imidazopyridine derivative
Unrelated to BZ
Hypnotic actions
Binds directly to BZ receptor and increases GABA-mediated inhibition
Used for short-term treatment of insomnia

19

Ramelteon

Activated melatonin receptors in the superchiasmic nuclei of the CNS and decreases the latency of sleep onset
Minimal rebound insomnia and abuse potential

20

Orexin antagonists

Orexin is a peptide found in the hypothalamus and is involved in wakefulness
Suvorexant is an antagonist at orexin receptors, acts as a hypnotic