Acute alcohol intoxication - Pharmacology B. Pharma 5th Semester PDF Notes

Alcohol

Content

Alcohol

•       Acute alcohol intoxication

•       Methanol poisoning and its treatment

•       Mechanism of disulfiram

•       Drugs used for the treatment of alcohol dependence

Intended Learning Outcomes
At the end of this lecture, student will be able to

•       Explain acute alcohol intoxication

•       Explain methanol poisoning and its treatment

•       Outline the mechanism of disulfiram

•       List the drugs used for the treatment of alcohol dependence

Acute alcohol intoxication

Life Threatening signs of alcohol poisoning include:

·         Inability to Wake up

·         Irregular breathing (10 second or more between breaths)

·         Vomiting

·         Seizures

·         Slow breathing (fewer than 8 breaths per minute)

·         Hypothermia (Low body temperature), bluish skin color, paleness

•       600ml of pure alcohol in 70 Kg bodyweight: Fatal effect

•       Coma due to CNS depression, severe hypoglycemia

•       Treatment

•       Maintenance of vital functions

•       Thiamine 100 mg (Bolus IV)

•       Glucose 50% 50 ml IV for hypoglycemia

•       MgSO₄2-4g IV over 1-2 hrs

Chronic alcoholism

Neuropsychiatric syndromes

•       Korsakoff’s psychosis, hallucinosis, suicidal tendencies, wernicke’s encephalopathy

Nutritonal deficiencies

•       Polyneuritis due to thiamine deficiency & anaemia

Organ damage leading to

•       Hepatic cirrhosis, chronic pancreatitis, cardiomyopathy, optic nerve degeneration

Alcohol dependence

•       Precise mechanism not known

•       Upregulate NMDA receptor & voltage sensitive calcium channel

•       Down regulate GABA_A mediated ressponses

•       Treatment:

–      Detoxification

–      rehabilitation

Drugs for Alcohol dependence

•       Aversion drugs: Disulfiram, citrated Ca cyanide

•       Opioid antagonist: Naltrexone, Nalmefene

•       Dopamine Antagonist: Tiapride

•       NMDA Antagonist: Acamprosate

•       Supporting drugs: Lithium, carbamazepine, topiramate

Disulfiram

•       12 hours alcohol free

•       500 mg as single daily dose  for 1-2 weeks

•       125 – 250 mg OD as maintenance dose

•       Continued upto 1 year

•       Inhibits aldehyde dehydrogenase

•       Inhibits dopamine beta oxidase

Alcohol

•       Drug interactions

–      Inhibits metabolic degradation of warfarin, theophylline, benzodiazepine, carbamazepine, tricyclic antidepressants

•       contraindications

–      Hepatic and circulatory diseases

–      Uncontrolled DM

–      Alcoholics with obvious personality changes

Methyl Alcohol

Pharmacological Actions

•       Initial symptoms similar to ethanol

•       Later symptoms due to:

•       CNS depression

•       Acidosis: because of formic acid and other organic acids

•       Toxic effects of formaldehyde & formic acid on retinal cells

•       Delayed symptoms

•       Headache vertigo, nausea, vomiting

•       Severe abdominal pain

•       Dyspnoea

•       Motor restlessness

•       Bradycardia

•       Coma followed by death

•       Preceded by blindness

Treatment

•       Hospitalization & nursing care

•       Gastric lavage, activated charcoal

•       Treatment of acidosis/ hypoglycemia

•       Inhibition of methanol metabolism: ethanol, fomepizole

•       Promotes metabolic degradation of formate

•       Folinic acid 1mg/Kg IV wih folic acid img/Kg IV 4 hourly for 6 doses

•       Hemodialysis in severe case

Summary

•       Chronic alcoholism leads to Korsakoff’s psychosis, hallucinosis, suicidal tendencies, wernicke’s encephalopathy Hepatic cirrhosis, chronic pancreatitis, cardiomyopathy, optic nerve degeneration

•       Regular consumption of alcohol associated with hypertension and conduction defects

•       Methanol poisoning: Coma preceded by blindness

•       Hemodialysis in severe case of methanol poisoning

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