Pharmacology

1. ETHYL ALCOHOL

2. INTRODUCTION
 Alcohols – Hydroxy derivatives of aliphatic
hydrocarbons
 Manufactured by fermentation of sugars
C6H12O6 2CO2 + 2C2H5OH
• Fermentation proceeds till alcohol content reaches 15%
• Then reaction is inhibited by alcohol itself
STARCH MALTOSE
• Major source – Mollases, byproduct of sugar industry
ZYMASE (IN YEAST)
CONVERTASE

3. ALCOHOLIC BEVERAGES
 MALTED LIQUORS
 WINES
* LIGHT
* FORTIFIED
* EFFERVESCENT
 SPIRITS

4. MALTED LIQUORS
 Obtained by fermentation of germinating cereals
 Undistilled – alcohol content is low (3-6%)
 Eg : Beers , Stout

5. WINES
• Fermentation of natural sugars as present in grapes
and other fruits
• Undistilled
• Light wines (alcohol content 9-12%)
• Fortified wines (alcohol content 16-22%)
• Effervescent wines (alcohol content 12-16%)
• Dry – all sugar fermented
• Sweet – some sugar is left

6. SPIRITS
 Distilled after
fermentation
 Alcohol content varies
from 40-55%
 Eg : Brandy, Whisky , Vodka , Rum etc

7. OTHER FORMS
 ABSOLUTE ALCOHOL – 99% w/w ethanol
 RECTIFIED SPIRIT – 90% w/w ethanol produced
from mollases by distillation
 PROOF SPIRIT- 100% proof spirit is 49.29% w/w
or 57.1% v/v alcohol
 METHYLATED SPIRIT (INDUSTRIAL)- denatured
spirit, adding 5 parts of methanol to 95 parts of
rectified spirit. Tinted blue

8. PHARMACOLOGICAL ACTIONS
 Local actions
 Central nervous system
 Cardio vascular system
 Body temperature
 Respiratory system
 Gastrointestinal system
 Skeletal Muscle
 Kidneys
 Reproductive system
 Endocrine system

9. LOCAL ACTIONS
 Mild rubefacient and counterirritant on skin
 Applied to delicate skin or mucous membranes
produce irritation and burning sensation
 When injected, it causes intense pain, inflammation
and necrosis followed by fibrosis

10.  Applied to surface , alcohol is an astringent –
precipitates surface proteins and hardens skin
 Acts as an antiseptic – 100% ethanol is more
dehydrating but poorer antiseptic than 90%
ethanol
 Does not kill bacterial spores

11. ACTIONS ON CNS
 Neuronal depressant
 Excitation and euphoria experienced
at lower plasma
concentration (30-60mg/dl)
 Hesitation , caution, self criticism
and restraint lost first
 Mood and feelings altered,
anxiety may be allayed

12. • With increasing concentration (80-150mg/dl) mental
clouding, disorganisation of thought , impairment of
attention and memory, alteration of gait and
perception, and drowsiness supervene.
• At 150-200mg/dl , person is sloppy, ataxic and
blackouts occur
• 200-300mg/dl result in stupor
• Above this, unconsciousness prevails, medullary
centres paralysed and death may occur

13.  Can produce anaesthesia
 Cause slowing of reflexes
 Performance is impaired, fine discrimination and
precise movements obliterated, errors increase
 Can induce sleep. Sleep architecture disorganised
and sleep apnoea aggravated
 Headache, dry mouth, laziness , disturbed mood ,
impaired performance may occur next morning

14.  Raises pain threshold- severe pain can precipitate
confusion and convulsions
 When acts on brain, it exerts anti convulsant action,
but this is followed by lowering of threshold:
seizures maybe precipitated in epileptics
 Chronic alcohol abuse damages brain neurons,
cause shrinkage of brain

15. ACTIONS ON CVS
 Small doses – cutaneous (especially in face) and
gastric vasodilatation. Skin is warm and flushed. BP
not affected
 Moderate doses- tachycardia, mild rise in BP (due to
mild muscular activity and sympathetic stimulation)

16.  Large doses – direct myocardial and vasomotor
centre depression and fall in BP
• Chronic alcoholism contribute to hypertension and
lead to cardiomyopathy.
• Atrial fibrillation and other cardiac arrhythmias may
occur due to conduction defects and Q-T
prolongation

17. ACTION ON BLOOD
 Regular intake of small to moderate amounts
of alcohol (1-2 drinks) raise HDL- cholesterol
levels and decrease LDL oxidation
 Responsible for the 15-35% lower incidence
of coronary artery disease
 Protection lost if ≥ 3 drinks consumed daily
 Megaloblastic anemia is common in chronic
alcoholics due to interference with folate
metabolism

18. ACTION ON BODY TEMPERATURE
 Reputed to combat cold
 Produce a sense of warmth due to
cutaneous and gastric vasodilatation,
but heat loss is actually increased in
cold temperature
 High doses depress temperature
regulating centre

19. ACTION ON RESPIRATORY SYSTEM
 Brandy or whiskey reputed as respiratory
stimulants in collapse
 They irritate buccal and pharyngeal
mucosa – transiently stimulate respiration
reflexly
 Direct action of alcohol on respiratory
centre is a depressant one

20. ACTION ON GIT
 Dilute alcohol (optimum 10%)
put in stomach by Ryle’s tube
is a strong stimulant of gastric
secretion (acid)
 Higher concentration (above
20%) inhibit gastric secretion
causing vomiting, mucosal
congestion and gastritis

21.  Alcoholism – important cause of chronic
gastritis
 Lower esophageal sphincter tone reduced
 Bowel movements may be altered in either
direction
 Acute pancreatitis – complication of heavy
drinking

22. ACTION ON LIVER
 Mobilize peripheral fat and increases fat synthesis in
liver in a dose dependent manner
 Proteins accumulate in liver as their secretion is
decreased
 Chronic alcoholism exposes liver to oxidative stress
and cause cellular necrosis followed by fibrosis

23.  Acetaldehyde produced during metabolism of
alcohol – damage hepatocytes and induce
inflammation
 Increased lipid peroxidation and glutathione
depletion occurs
 These combined with vitamin and other nutritional
deficiencies – alcoholic cirrhosis
 Regular intake induce microsomal enzymes

24. ACTION ON SKELETAL MUSCLE
 Produce little direct effect
 Fatigue caused by small doses
 Muscle work increased or
decreased depending on
predominating central effect
 Weakness and myopathy –
chronic alcoholism

25. ACTION ON KIDNEYS
 Diuresis
 Due to water ingested along with
drinks and alcohol induced
inhibition of ADH secretion
 Does not impair renal function

26. ACTION ON REPRODUCTIVE SYSTEM
 Reputed as aphrodisiac
 Aggressive sexual behaviour- due to loss of restraint and
inhibition
 Performance of sexual act is often impaired
 Chronic alcoholism produce impotence, testicular atrophy ,
gynaecomastia and infertility in both men and women
 Uterine contractions suppressed at moderate blood levels

27. ACTION ON ENDOCRINE SYSTEM
 Moderate amounts increase adrenaline release
which cause hyperglycemia and other
sympathetic effects
 Acute intoxication – hypoglycemia and
depletion of hepatic glycogen because
gluconeogenesis is inhibited
 Glucagon fails to reverse it and glucose must
be given to counteract hypoglycemia