Ethyl alcohol

Pharmacology

1. E THYL ALCOHOL

2. INTRODUCTION Alcohols – Hydroxy derivatives of aliphatic hydrocarbons Manufactured by fermentation of sugars C 6 H 12 O 6 2 CO 2 + 2 C 2 H 5 OH 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