Sedative Hypnotics

Definitions

Sedative: Decreases excitement, motor activity, & responsive to stimuli; calms, produce drowsiness without sleep

Hypnotic: Induces/maintains arousable natural sleep, quicker onset, steeper dose response; shorter duration of action than sedatives. Large doses of hypnoticsà GA

1857: Bromides, 1869: Chloral hydrate,1903: Barbiturates, 1960: Benzodiazepines (BZD); now most prescribed

Sleep Architecture

Different stages show different EEG waves

1. Rapid eye movement (REM) sleep: Paradoxical sleep: eye movements, dreams, Irregular respiration, HR & BP fluctuate; 20-30% seep time

2. NREM Sleep: Stage 1 to 4. Stage I: dozing. II: Unequivocal. III: Deep sleep transition. IV: Cerebral sleep

Classification of sedative hypnotics

1. BARBITURATES

Ultra Short: thiopentone, hexobarbitone, methohexitone

Short acting: Butobarbitone, secobarbitone, pentobarbitone

Long acting: Phenobarbitone, Mephobarbitone

2. BENZODIAZEPINES:

Hypnotics: Diazepam, Nitrazepam, Midazolam, triazolam

Antianxiety: Diazepam,oxazepam,lorazepam, lprazolam

Anticonvulsant: Diazepam, clonazepam, clobazam

Newer Non BZD: Zopiclone, Zolpidem

Miscellaneous: Chloral hydrate, trichlophos, paraldehyde, [Opiates, antihistaminics not used as hypnotics]

Category: Pharmacology Notes