Sedative-Hypnotics

Question 1

Sedative-Hypnotics

Answer 1

1. barbiturates, anxiolytics, and alcohol.
2. CNS depressants, dose dependent
   
   1. low dose: reduce arousal and motor activity
   2. moderate doses: sedation and sleep
   3. high doses: anesthesia, coma, and death.
3. Initial increase in activity/feelings of elation are due to their suppression of inhibitory mechanisms in the brain.
   
   1. ultimate sedating and hypnotic effects result from suppression of excitatory mechnisms.
4. Chronic use produces tolerance and psychological/physical dependence.
5. Abrupt cessation: withdrawal syndrome with tremors, anxiety, nausea, vomiting, paranoia, and possible hallucinations, delirium, and convulsive seizures.
6. Synergistic effects: combingin an anxiolytic with a barbiturate or alcohol can have lethal consequences due to the superadditive nature of their actions on the brain structures that control respiration.
7. Cross-tolerance: when tolerance develops to one sedative-hypnotic, it is likely to be shown for other sedative hypnotics as well.

Question 2

Barbiturates

Answer 2

amobarbital, pentobarbital, secobarbital, and phenobarbital

USE: sedatives and anesthetic agents. Due to lethal effects and safer more effective drugs, they are infrequently prescribed.

produce mild sedation to anesthesia, coma, and death.

youngh children and older adults and people experiencing pain, may have a paradoxical excitement with barbiturates.

MODE OF ACTION: interrupting impulses to the reticular activating system.

Side Effects: slurred speech, nystagmus, dizziness, irritability, and impaired motor and cognitive performance.

OD: ataxia, confusion, agitation, respiratory depression, and death.

Alleviate Insomnia: soporific effects generally last for only a few weeks, then total sleep time may actuall fall.

Can decrease REM sleep and abrupt cessation can give REM rebound and nightmares.

Chronic use of barbiturates: tolerance and psychological and physical dependence. Not equal for all affected systems.

tolerance for the sleep-inducing actions, but not to repiratory centers. Thus, taking more will not give sleep, but stop breathing.

Withdrawal symptoms are generally severe and w/o medical supervision can be life-threatening.

Once used commonly for suicides and accidental deaths.

Question 3

Benzodiazepines

Answer 3

Anxiolytics (tranquilizers and anti-anxiety drugs): most widely-used psychiatric medication.

Benzodiazepines: most commonly prescribed.

diazepam, alprazolam, oxazepam, triazolam, chlordiazepoxide, and lorazepam.

USE: relieve anxiety, treat sleep distrubances, seizures, cerebral palsy, and other dixorders with muscle spasms, and alcohol withdrawal.

MODE OF ACTION: stimulate the inhibitory action of GABA.

Side Effects: drowsiness, dizziness, letheargy, slurred speech, ataxia, impaired psychomotor ability.

irritability, hostility, paradoxical excitation or agitation, increased appetite, weight gain, skin rash, blood dyscrasias, poor sex, disorientation, and confusion, sleep bad, anterograde amnesia, and depression.

Lowering the dose often alleviates severe effects.

Relaxation, euphoria, and sense of well-being produced by benzodiazepines promote psychological dependence.

Chronic use gives tolerance and physcial dependence.

Withdrawal: severe, abrupt cessation may induce rebound hyperexcitability, accompanied by seizures, depersonalization, panic and stroke.

Question 4

Azapirone

Answer 4

Azapirone (buspirone): first anxiolytic that reduces anxiety w/o sedation.

non-addictive, non-habit forming, and not subject to abuse.

must be taken for several weeks before it is effective, unlike benzodiazepines and anxiolytics.

cool!