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.