AN OVERVIEW ABOUT PHARMACOLOGICAL ACTIONS,TOXICITY PHARAMETERS,GUIDELINES FOR SAFE DRINKING,CLINICAL USES,METHYL ALCOHOL.THIS FOR ALL MEDICAL AND PHARMACY STUDENTS.

1. Topic- Ethyl and Methyl Alcohols
By – Nilesh Sharma (pharm.d 2nd year)

2. Ethyl Alcohol (Ethanol)
 Alcohols are Hydroxy deriatives of aliphatic hydrocarbons.
 Alcohol is manufactured by fermentation of sugar.
 C6H12O6 → 2 C2H5OH + 2 C02. ( PRESENCE OF ZYMASE ENZYME IN YEAST).

3. Alchololic beverages
A.Malted liquors – Obtained by fermentation of germinating cereals. Alcohol Content is low(3 to 6%)
Example – beers,Stout.
B.Wines – Produced by fermentation of natural sugars as present in grapes and other fruits.
There are 3 typs of wines .
1. Light wines – Alcohol content (9to12%) example .claret, cider. Cannot exceed 15%
2. Fortified wines-Alcohol content (16 to 22%) example port ,Sherry.
3. Effervescent wines – alcohol content (12 to 16%) example champagne.
C.Spirits- These are produced by distillation of the fermented broth. Alcohol content is (40 to
55%)example Rum,whiskey,vodka etc

4. Other forms of alcohol
 1. Absolute alcohol - 99% w/w ethanol. (Dehydrated alcohol)
 2. Rectified spirit - 90% w/w ethanol produced from fermented molasses,by distillation.
 3. Proof spirit – 49.29% w/w ethanol.
 4.Methylated spirit (industrial) – also called denatured spitit is produced by adding 5 parts of
wood naphtha (methyl alcohol) to 95 parts of rectified spirit so as to render it unfit for drinking.
It can be applied on the skin for antiseptic ,cleaning and astringent purposes.

5. Pharmacological Actions.
 1. Local action –
 ethanol is a mild rubefacient and counter irritant.
 By evaporation it produces cooling .
 Injected causes intense pain and inflammation.
 Injected around nerve it produces permanent damage.
 Alcohol is an astringent.
 By precipitating bacterial proteins it acts as an antiseptic. this effect is predominant at 70-90%
alcohol.

6. 2.CNS
It is a neuronal depressant.
BAC (Mg/dl) Clinical effects
30-60 mg/dl Apparent excitation and euphoria.
100-150 mg/dl Impaired motor function , impairment of
memory , drowsiness.(feel high)
150-200mg/dl sloppy ,ataxic and drunk,black outs.
200-300 mg/dl Emesis , stupor.
300-400 mg/dl coma
>500 mg/dl Respiratory failure , death.

7. Meachanism of action .
1.It promotes GABAA Receptor mediated synaptic inhibition (through chloride
channel opening).
2.Inhibits NMDA type of excitatory amino acid receptor which has been implicated
in memory impairment cause by alcohol.
3.Ethanol can indirectly reduce neuro transmitter release by inhibiting voltage
sensitive neuronal calcium channels.
4.It also activates specific type of k+ channel in certain brain areas .
5.The activety and translocation channel/enzyme proteins in the membrane could
be affected by alcohol through protein kinase C (PKC) and (PKA) mediated alteration
in the state of their phosphorylation.

8. 3.CVS
The effects are dose dependent.
1.Small doses : produces cutaneous and gastric
vasodilatation. Skin is warm and flushed . BP is not
effected.
2.Moderate doses :causes tachycardia , mild rise in BP.
3.Large doses :cause direct myocardial as well as
vasomotor depression and fall in BP.

9. 4.Blood
• Regular intake of alcohol ( 1 to 2 drinks) has been found to raise HDL level and dec LDL level.
• This may be responsible for the (15 to 35%) lower incidence of CAD .
• Mild anaemia is common in chronic alcoholism is due to interference with folate metabolism.
5.Body temperature
• It produces a sense of warmth due to cutaneous and gastric vasodilatation , but heat loss is actually inc in
cold surrounding .
• High doses depress temp regulating system .
6.Respiration
• Alcoholic beverages acts as respiratory stimulant in collapse by irritating buccal and pharyngeal
mucosa.
• How ever it is better not to depend on this bcz the direct action of alcohol on respiratory center is
only a depressant one.

10. 7.GIT
1.Higher conc.(>20%) inhibit gastric secretions , cause
vomiting , mucosal congestion and gastritis.
2.Alcoholism is an imp cause of chronic gastritis.
3.LES tone is reduced by alcohol- bowel movement may be altered in either directions.
4.Acute pancreatitis is a complication of heavy drinkinf
8.Skeletal muscle
1. Fatigue is allayed by small doses.
2.Weakness and myopathy occurs in chronic alcoholism.

11. 9.liver
Causes alcoholic liver
cirrhosis
1. By alcohol metabolism acetaldehyde gets accumulated and damages the function of
liver.
2. It induces inflammation and damage the hepatocytes.
3. Regular intake induces microsomal enzymes present in liver.

12. 10.Kidney
1.Diuresis is often noticed after alcohol intake
2.Due to water ingested and alcohol induced inhibition of ADH secretion.
3.Alcohol does not impair renal function .
11.Endocrine effects
1.Alcohol increases adrenalin release which causes hyperglycemia.
2.Acute intoxification is often associated with hypoglycemia and depletion of hepatic
Glycogen , because gluconeogenesis is inhibited ,glucose must be given to counteract it.
3. Uterine contractions are suppressed at moderate blood levels.

13. 12. sEX
• Chronic alcoholism can produce IMPOTENCE,TESTICULAR ATROPHY ,GYNAECOMASTIA and
INFERTILITY IN BOTH Men and Women.

14. Pharmacokinetics
A absorption from intestine is very fast
Peak levels are attained after 30 min.
D distributed widely in the body.
crosses blood brain barrier (BBB)and also placenta.
conc.in brain =conc. in blood.
M gets oxidised in liver to an extent of 98%.
metabolism of alcohol follows zero order
kinetics
constant rate (8-12 ml /hr)
Eexcretion is through kidney and lungs.
Concentration in exhaled air is about 0.05% of blood concentration.
This is utilized for medico legal determination of drunken state using breath analyser.

15. Contraindication
1.Peptic ulcer , hyper acidity , and gastroesophageal reflux disease
(alcohol increases gastric secretion and reflex LES).
2.Epileptics : seizures may precipitated.
3.Severe liver disease patients.
4.Pregnant women :even moderate drinking cause foetal alcohol
syndrome resulting in intrauterine growth retardation, low IQ, facial and
other abnormalities.

16. Guidelines for safe drinking.
1.On an average 1-2 drinks per
day is usually safe.
2. Do not drive or engage in
hazardous activities after
drinking.
3. Do not drink if any
interacting
drug has been taken.

17. Clinical use
As antiseptic
1.Rubefacient and counter irritant for sprains , joint pains.
2.As appetite stimulant and carminative:30-50ml of 7-10% alcohol may
be taken as beverages and tinctures.
3.To treat methanol poisoning.

18. Aldehyde dehydrogenase inhibitor
Disulfiram
1. It inhibits enzyme aldehyde dehydrogenase probably after conversion into active metabolites.
Symptoms:
1. Flushing , burning sensation ,
throbbing headache ,perspiration,uneasiness,tightness in chest,dizziness,vomiting,mental
confusion.
Duration(1-4 hrs).
1. Disulfiram has been used in chronic
alcoholics who are motivated and
sincerely desire to leave the habit.

19. Methyl Alcohol
Methanol is also a CNS depressant as ethanol.
Even 15 ml of methanol causes blindness
30 ml causes death
75-100 ml is regarded as fatal dose.
Manifestations of methanol poisoning
Vomiting , headache , epigastric pain , uneasiness ,
bradycardia , hypotension
Methanol is metabolised to formaldehyde and formic acid.
The specific toxicity of formic acid is retinal damage.

20. REFERENCE: Kd.Tripathi.
 FOR MORE INFO-
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