Largely replaced barbiturates and meprobamate in the treatment of anxiety and insomnia

Not necessarily the best choice for anxiety and insomnia

Flumazenil (benzodiazepines antagonists) selectively reverse benzodiazepine effects and useful in diagnosis and in treatment of intoxication with them

Disadvantages: Long lasting 'hangover' effects and the development of tolerance and physical dependence

Used most primary care rather than psychiatry

Rapid onset

Limit use to less than 2 weeks

Target: Gamma-aminobutyric acid (GABAA) receptors, which mediate inhibitory synaptic transmission throughout the central nervous system

Binding of GABA to its receptor triggers an opening of the central ion channel, allowing chloride through the pore

Influx of chloride ions causes hyperpolarization of the neuron and decreases neurotransmission by inhibiting the formation of action potentials

BZDs enhace the response to GABA by facilitating the opening of GABA-activated chloride channel

Short acting (3-8 hours)

Intermediate (10-20 hours)

Long acting (1-3 days)

Reduction/Relief of anxiety and aggression

Sedative/Hypnotic

Reduction of muscle tone

Anterograde amnesia

Anticonvulsant effect

Anxiety disorders: Reduction of anxiety - at small doses, uses as anxiolytics

Seizures: Antiepileptic and anticonvulsant

Muscular disorders: Reduction of muscle tone and coordination

Sedation, amnesia, anesthesia: Anterograde amnesia - minor surgical or invasive procedures can be performed without leaving unpleasant memories

Sleep disorder: Sedation and induction of sleep; at relatively higher dose can reduce sleep latency, increase sleep time

Drowsiness and confusion

High doses can cause ataxia and precludes activities that require fine motor coordination

Myasthenia gravis

Infants < 6months

Pregnant and lactation mother

Elderly with heart/lung/liver/kidney/dysfunction

Drug that act as central nervous system (CNS) depressants

Formerly to sedate patients or to induce or maintain sleep

Largely replaced by benzodiazepine because of tolerance, physical dependence and withdrawal syndrome

All barbiturates are controlled substances

Ultra-short acting (20 min)

Short acting (3-8 hours)

Long acting (1-2 days)

Work by increasing GABA transmission throughout the brain, which enhances the inhibitory action of GABA

Barbiturates potentiate GABA action on chloride entry into the neuron by prolonging the duration of the chloride channel openings

Block excitatory glutamate receptors

CNS

Respiratory

Other systems

Anesthesia: Ultra-short-acting barbiturates, such as thiopental, have been used IV to induce anesthesia but have largely been replaced by other agents

Anticonvulsant: Has specific anticonvulsant activity that is distinguished from the nonspecific CNS depression

Sedative/Hypnotic: Used as mild sedatives to relieve anxiety, nervous tension, and insomnia

Cause drowsiness, impaired concentration, & mental & physical sluggishness

Hypnotic doses cause drug "hangover" may lead to impaired ability to function normally for many hours after waking

Nausea and dizziness

Patient with acute intermittent porphyria

With sedating properties, such as diphenhydramine, hydroxyzine, and doxylamine, are effective in treating mild types of situational insomnia

Most selective anxiolytic currently available

Useful chronic treatment of GAD and has an efficacy comparable to that of the BZDs

Has slow onset of action and not effective for short-term

An oral non-benzodiazepine hypnotic that also acts on the BZ1 receptor

Rapidly absorbed

Extensively metabolized by oxidation and demethylation

An oral non-benzodiazepine hypnotic similar to zolpidem; however, zaleplon causes fewer residual effects on psychomotor and cognitive function compared to zolpidem

Metabolized by CYP3A4

Not structurally related to benzodiazepines, but it selectively binds to the benzodiazepine receptor subtype BZ1

Has np anticonvulsant or muscle-relaxing properties

Provides a hypnotic effect for approximately 5 hours

Undergoes hepatic oxidation by the CYP450 system to inactive products

Adverse effects: Nightmares, agitation, anterograde amnesia, headache, GI upset, dizziness and daytime drowsiness

Effective in the treatment of chronic anxiety disorders and should be considered as first-line agents, especially in patients with concerns for addiction or dependence

A selective agonist at the MT1 and MT2 subtypes of melatonin receptors

Has minimal potential for abuse, and no evidence of dependence or withdrawal effects has been observed

Side effects: Dizziness, fatigue and somnolence