Transcript File

Sedatives & Hypnotics
•
•
Sedatives – calming effect
Hypnotics –produce sleep
• They include Chloral
Hydrate & Barbiturates
BARBITURATES
USES:

As sedatives

Hypnotics.

Anaesthetic when given I / V.

In psychiatric disorders,
strychnine poisoning
epilepsy
and
CLASSIFICATION

Long acting:
1 8 to 12 hrs
e.g. Barbitone, Phenobarbitone

Intermediate acting:
e.g. Amylobarbitone
½  4 to 8 hrs

Short acting:
¼  2 to 4 hrs
e.g. Cyclobarbitone

Ultra short acting:
(for
on set of action immediate .
e.g. Thiopentone Sodium
anaesthesia)
ABSORPTION: From

GIT including rectum

Subcutaneous tissue
METABOLISM:

They are concentrated in liver for sometime
and then evenly distributed into body fluids.
EXCRETION :

By kidney
SIGN & SYMPTOM
ACUTE POISONING

Drowsiness

Confusion, excitement, delirium, hallucinations

Ataxia, Vertigo, Slurred speech & stupor

Headache

Paraesthesias

Decreased peristalsis in deep coma (bad
sign) bowel sounds absent.

Hypothermia

Barbiturate blisters on the skin

BP falls

Cheyne Stokes breathing

Oliguria.
BARBITURATE BLISTERS


Barbiturate blisters are found on sites of
friction or pressure.
Blisters are commonly found at interdigital
clefts, axilla and inner aspects of the knees
and calves.
BARBITURATE AUTOMATISM

Normal doses of barbiturates induce natural sleep
but occasionally instead of sleep there is mental
confusion.

This Phenomenon is observed in cases where
insomnia is due to pain & is not countered by
analgesics. In these cases patient automatically
increases the dose and frequency of barbiturate in
order to induce sleep but acquires mental confusion
rather than the desired effect

The concept of automatism is recently
questioned now.

They feel that confusion or forgetfulness
cannot account for over whelming
over
dosage.

It is possible that these are cases of
intentional suicide or alcoholics.
CHRONIC POISONING
Chronic poisoning (may lead to addiction).


It may occur when barbiturates are used
therapeutically in epilepsy or psychoneurotic
patients.
Tremors

Ataxia

Delirium, hallucinations.

Vertigo

Emotional instability

General mental deterioration

Urine may show albumin, sugar and casts

Drug dependence is both physical and
psychological


Fatal Dose:

Short acting
1–2g

Medium acting
2–3g

Long acting
3–4g
Fatal Period:

1 – 2 days
TREATMENT

Gartic lavage with warm water mixed with
Potassium permanganate and suspension of
animal charcoal or tannic acid.

For
purgation
concentrated
MgSo4 should be left in stomach.

Keep the patient warm.

Keep the airways clean
solution
of

Artificial respiration

O2 administration

Amphetamine sulphate 10mg I/V every 30
minutes .

Forced osmotic diuresis with IV mannitol

Antibiotics
MEDICOLEGAL ASPECTS

Mostly suicidal.

Accidental.

Rarely for homicidal purpose.

Judicial execution in USA is carried out by a lethal
intravenous injection of which sodium pentothal is
the chief ingredient, the other ingredients being
saline, Pavulon (muscle relaxant) and potassium
chloride.