1. ii-SEDATIVES AND HYPNOTICS
• Sedatives are drugs which produce a claiming
effect on the central nervous system while
hypnotics are drugs which produce sleep
• The important substances which are
considered from this group are:
1- Chloral hydrate.
2- Barbiturates.
2. CHLORAL HYDRATE
It is a powerful and reliable hypnotic.
In small doses, it produces natural
sleep.
But in larger doses (5 to 6 gms), It is a
depressant of the central nervous
system and paralysis the vital centers.
6. Medicolegal aspects
• Accidental poisoning may result from a
large dose used as a hypnotic.
• It is rarely used for suicide.
• It is often added to liquor for a greater
kick.
• It is covertly added to beer with
homicidal intent.
7. Medicolegal aspects Contd…
• Chloral hydrate (some times known as
dry wine) is used in alcohol to produce
sleep in, say, a watchman.Its action is so
rapid that it has been given the name
“knock out drops”, it renders a victim of
robbery or rape suddenly helpless.
• Long continued use leads to addiction.
8. iii-BARBITURATES
• The compounds are used as sedatives,
hypnotics and, when given intravenously, as
anesthetics.
• They are also useful in psychiatric disorders,
epilepsy, and strychnine poisoning.
• Barbiturates are classified into four groups as
follows, depending on whether their action is
long, intermediate, short, or ultrashort.
9. 1.Long action—Effect from 1 to 8-12
hours—
• Fatal dose: 3-4 gms.
a) Barbitone (veronal-white tablets)
b) Phenobarbitone (Gardenal, luminal-
small white tablets).
10. 2.Intermediate action—effect from ½ to 4-8
hours—
• Fatal dose: 2-3 gms.
a) Butobarbitone (soneryl-pink tablets)
b) Pentobarbitone (Nembutal-yellow capsules)
3.Short action—effect from ¼ to 2-4 hours-
• Fatal doses: 1-2 gms.
a) Cyclobarbitone (Phanoderm-white tablets).
b) Hexobarbitone (Evipan-white tablets).
11. 4.Ultra short action.. For Induction of
anaesthesia
• Fatal dose: 1 gm.
a) Thiopentone sodium (pentothal-white
powder or solution).
b) Methohexobarbitone (Brevital-white
powder or solution.
12. Signs and Symptoms
Acute intoxication presents in following
stages
Early manifestations
Late manifestations
Stage of recovery and barbiturates
blisters
Coma and death
Barbiturates automatism
13. Early manifestations
Initially there will be
Giddiness,
Ataxia,
Slurred speech
Followed by
Stupor
The limbs become flaccid,
Reflexes lost
Alternate dilatation and contraction of pupil.
14. The face will become cyanotic
The respiration becomes slow, periodic
(cheyne- strokes)
There will be fall of blood pressure
Body temperate will be sub normal
Oliguria may develop
Late Manifestation
15. Patient may recover from coma, and there
may be dermatological changes called
barbiturates blisters. These blisters are
formed at friction areas such as axilla, inner
aspect of knee, calf, interdigital clefts, etc.
The blistering is now explained to be due to
dependent skin edema from venous return ,
consequent, to immobility during comatose
state.
Stages of Recovery
16. Finally coma will develop leading to death due
to
Respiratory failure which may be
sudden and unexpected.
Edema lungs, bronchopneumonia
cardiac failure etc.
Coma and Death
17. Barbiturate automatism
When a person becomes addicted to
barbiturates,he forgets that he has taken tablet
and so takes more and more tablets till
intoxication occurs.
Medicolegal Importance
More pronounced with alcohol consumption and
intended suicide.
18. Chronic intoxication
(Barbiturate Addiction)
Signs and symptoms
Apathy
Loss of power of concentration
Vertigo
Tremors
Ataxia
Thick speech
Delirium hallucination (visual)
Emotional instability
20. Treatment
Increase elimination of drug
forced diuresis
alkalinization of urine
dialysis
hemoperfusion
Conservative management with good nursing care
symptomatic
suppotive care
Psychiatric after care
