Alcohols

Dr. Nadeem akhtar

MBBS.M.Phil

Asst. Professor Pharmacology

Amna Inayat Medical College

Shaikhupura

• In western societies beer & wine were main component of daily life until 19th century

Epidemiology

• As systems of water sanitation improved beer and wine become less component of daily life

• Now alcoholic beverage like distilled preparations of higher concentrations of alcohol now acceptable for of recreation

• Today alcohol is widely consumed like other sedating & hypnotic drugs

• It is used almost all the societies of the world

Epidemiology

• In the USA 75% of adult population drink alcohol regularly

• Majority of the drinking population enjoy the pleasurable effects of alcohol without risking their health

• However 8% of US population have alcohol used disorder

• Despite the heavy investment alcoholism remains common chronic disease & difficult to treat

ETHANOL

• Ethanol is almost water soluble molecule absorb rapidly from G.I.T

• The volume of distribution for ethanol approximate total body water (0.5-0.7 l/kg)

• Women have higher peak concentration level than men b/cz women have lower total body water content and difference in first pass metabolism

Metabolism

• Over 90% of ethanol is oxidized by liver ad much of the reminder excreted by lungs and urine

• It is metabolized by two pathways

• 1)Alcohol dehydrogenase pathway: alcohol dehydrogenase (found in liver and gut) catalyses the conversion of alcohol to acetaldehyde using NADH as a co-facter

Metabolism

2) micorsomal ethanol oxidizing system: it uses NADPH as a co-factor converting ethanol to acetaldehyde, it is found in liver.

• Acetaldehyde thus formed is metabolized by aldehyde dehydrogenase to form acetate which is further converted to CO2 and water

Mechanism of action

• Acute ethanol exposure increase the function of GABA receptors

• Ethanol increases the fluidity of membrane of many types of cell, hence changing in membrane function including neurotransmitter receptors, membrane enzymes, ion channels and electron transport chain.

Pharmacological effects

• CNS: sedation, disinhibition, impaired judgment, slurred speech and ataxia, paraesthesia of hands and feet

• Relaxation of smooth muscles producing vasodilatation

• Relaxation of smooth muscle of uterus and given i.v to suppress premature labor

• hypoglycemia

Results of alcohol abuse

• WERNICKS KORSAKOF PSYCHOSIS: characterized by paralysis of external ocular muscles , ataxia, amnesia and confusion. This occur due to thiamine deficiency .

• TOLERANCE AND DEPENDANCE: this results from cns adaptation and partly by increase rate of metabolism

• CVS: arrhythmias, high blood pressure, atherosclerosis very common

• Increased risk of anemia's due to g.i bleeding and folic acid deficiency. Cardyomayopathy and direct injury to myocardium may occur

• G.I.T: increase appetite and gastric pancreatic secretions altars mucosal barriers and enhance the risk of gastritis

• Vomiting diarrhea to hypokalemia

• LIVER: because NAD depletion reduced gluconeogenosis, hypoglycemia, ketoacedosisand fat accumulation in liver, fatty liver---cirhosis--- death

• Iiver damage is more severe in females bcz gut metabolism is lower in females

• ENDOCRINES; gynaecomastia, atrophy and salt and water retention may occur

Fetal alcohol syndrome

• Ethanol use in pregnancy in first trimester is associated with teratogenic effect bcz it crosses placenta easily and cause defective neuronal and glial migration in the developing cns which is characterized mental retardation, underdevelopment of mid facial region, poor coordination and congenital heart defects

Drugs used in ethanol abuse

• Disulfiram

• Clonidine

• Fluxitine

• Propranolol

• Diazepam• Thiamine

OTHER ALCOHOLS

• METHANOL

• ETHYLENE GLYCOL

• These are mostly used for industrial purpose