mini quiz E - Sedative-Hypnotic Agents

Sedative-Hypnotic Agents

• Benzodiazepines

• Barbiturates

• Nonbarbiturate

What Are Benzodiazepines?

Class of psychoactive drugs used to treat anxiety, insomnia, and seizures

• Act on the central nervous system to produce a calming effect

• Often prescribed for dental anxiety or procedural sedation

Benzodiazepines Examples

diazepam (Valium®)

lorazepam (Ativan®)

midazolam (Versed®)

Benzodiazepines enhance the effect of

GABA (gamma-aminobutyric acid)

GABA (gamma-aminobutyric acid)

the main calming neurotransmitter in the brain, more specific anxiolytic action than the barbiturates; generally safer than the

barbiturates

Clinical Use Of Benzodiazepines

• situational anxiety

• generalized anxiety disorders

• panic attacks

• insomnia

• muscle relaxation

• anticonvulsant

• amnesic (NOT analgesia)

Dental Concerns Of Benzodiazepines:

1. Advise patients about additive CNS depressant effects

2. Elderly patients- benzos are lipid soluble, can accumulate in the fatty tissue of elderly & lead to CNS changes; decrease dose in liver/kidney disease

3. Advise pts. about sedation

4. Advise pts. about xerostomia

Adverse Reactions Of Benzodiazepines

• CNS depression

• Addiction Potential - Schedule IV Controlled Substance

• Teratogenicity - FDA category D or X (congenital malformations, Floppy infant syndrome)

• Thrombophlebitis - IV (local irritation due to use of propylene glycol as diluent)

• Overdose

CNS depression signs/symptoms

• drowsiness

• sedation

• blurred vision

• ataxia (unsteady gait)

• psychomotor impairment

• Disorientation

• confusion

• aggressive behavior and excitement can occur, esp. in elderly patients.

Overdose Of Benzodiazepines is treated with

flumazenil (Mazicon®), a benzodiazepine antagonist

Reverses CNS depression

Long acting Benzodiazepines

24-72 hours (or longer due to active metabolites)

chlodiazepoxide (Librium®)

*diazepam (Valium®)

clonazepam (Klonopin®) [can be used to tx burning mouth syndrome]

Intermediate Acting Benzodiazepines

6-24 hours

lorazepam (Ativan®)

Short Acting Benzodiazepines

2-6 hours

midazolam (Versed®) "twilight"

triazolam (Halcion®) Anxiety, panic disorders, anxiety with depressive symptoms

alprazolam (Xanax®)

Short term use; need to taper off!!!

Benzodiazepines interact with other CNS meds such as

barbiturates, antipsychotics, antidepressants, opioid analgesics, alcohol

cimetidine (Tagamet®), disulfiram (Antabuse®), isoniazid (INH®) and age

reduce metabolism of

benzodiazepines

Patients who smoke experience _____ sedation

less

What Are Barbiturates?

• sedative-hypnotic drugs that depress the central nervous system (CNS)

• Historically used for anxiety, insomnia, and seizure disorders

• Have largely been replaced by safer alternatives like benzodiazepines

• Examples: phenobarbital, pentobarbital, thiopental

Barbiturates Mechanism of Action

• Enhance GABA (gamma-aminobutyric acid activity, increasing inhibitory neurotransmission

• Result: sedation, hypnosis, and CNS depression

At high doses, Barbiturates can cause

anesthesia and respiratory depression

Barbiturates Pharmacologic Effects

1. Sedation and anxiety relief, sleep, anesthesia- a continuum with increasing doses

2. Anticonvulsant- long-acting agents are usually the most useful

3. Muscle relaxation- this action is inseparable from CNS (sedation) effects

** 4. No analgesia - in the presence of pain, agitation may result if an analgesic is not also given.

Barbiturates

Adverse Reactions

1. CNS depression- drowsiness, impaired performance and judgment; caution when driving

*2. abuse - euphoria, habituation, tolerance, withdrawal, dependence (physical and psychological

*3. Acute overdose - suicide attempt produces respiratory arrest (depression of respiratory center)

*4. Barbiturates are contraindicated in porphyria

Barbiturates

Therapeutic Uses

1. Medical- Treatment of epilepsy, for sedation or as antianxiety medication

2. Dental

a. Preoperative anxiety reduction oral or IM injections

b. induction of general anesthesia (IV barbiturates)

Ultrashort acting Barbiturates

Seconds to minutes (for induction of GA)

thiopental (Pentothal®)

methohexital (Brevital®)

Short acting Barbiturates

2-4 hours

(for insomnia; most abused)

pentobarbital (Nembutal®)

secobarbital (Seconal®)

Intermediate acting Barbiturates

4-6 hours

(insomnia; daytime sedation)

amobarbital (Amytal®)

butabarbital (Butisol®)

Long acting Barbiturates

6-12 hours (up to 48 hours)

(daytime sedation; anticonvulsant; little abuse)

** phenobarbital (Luminal®) anticonvulsant; sed-hyp; muscle relaxant

mephobarbital (Mebaral®)

primidone (Mysoline®)

cyclobenzaprine (Flexeril®)

Muscle relaxant

Nonbarbiturate

developed to provide the calming and sleep- inducing effects of barbiturates with fewer side effects and less risk of dependence or overdose

Examples

• Z-drugs (non-benzodiazepine hypnotics like zolpidem, zaleplon, eszopicione)

• chloral hydrate

• meprobamate

Nonbarbiturate Mechanism of action

They enhance the effect of GABA (gamma- aminobutyric acid - the main calming neurotransmitter in the brain.

This slows down nerve activity, leading to relaxation, reduced anxiety, and sleep

Nonbarbiturate Therapeutic Uses:

• Treat insomnia

• Reduce anxiety

• Help with muscle relaxation

• Used for preoperative sedation

Nonbarbiturate Side effects

• Drowsiness, dizziness, confusion

• Impaired coordination

• Dependence and withdrawal (especially with long-term use)

• In elderly patients: increased risk of falls and cognitive changes

Nonbarbiturate Examples

• chloral hydrate (Noctec®) used to sedate kids, can cause idiosyncratic rxn

• hydroxyzine hydrocholoride (Atarax®, Vistaril® )- kids, anxiolytic, antihistamine

• meprobamate (Equanil®, Miltown®)- tranquilizer

• *zolpidem (Ambien®, Ambien CR®)- newer nonbenzodiazipine sedative- hypnotic agent used for tx. of insomnia

Side Effect: heartburn (G.E.R.D.)

• Sonata® (short acting hypnotic) - For insomnia

• Lunesta®, Restoril® (intermediate acting) - For insomnia

Things to consider about Nonbarbiturate

• Lowest effective dose should be used

• drowsiness may last until the morning

• Somnolence, hallucinations, depression

• Short-term use

• don't take unless you can get at least 8 hrs. of sleep

Benzos =

"Better and safer" → Calm the brain gently

Barbiturates =

"Bad for breathing" → Can cause deep sedation and respiratory depression