Study unit 3.3 

• What are the possible mechanisms involved in the occurrence of tolerance to chronic alcohol intake?

Microsomal ethanol-oxidising system

• What are the toxic effects of chronic alcohol consumption on the liver and hepatic metabolism?
• What is Wernicke-Korsakoff-syndrome and how is it treated?

The paralysis of the external eye muscles, ataxia, and a confused state that can progress to coma and death, it is also associated with a thiamine deficiency. The treatment is to receive thiamine therapy. 

• Fully explain the foetal alcohol syndrome.

It is the chronic maternal alcohol abuse during pregnancy and is associated with teratogenic effects. Alcohol is a leading cause of mental retardation and congenital deformation. The abnormalities that have been characterized as foetal alcohol syndrome include:

• Intrauterine growth retardation
• Microcephaly
• Poor coordination
• Underdevelopment of midfacial region 
• Minor joint abnormalities
• Congenital heart defects 
• Mental retardation

This happens because ethanol rapidly crosses placenta and reaches concentrations in foetus similar to that of maternal concentration, the foetal liver has little to no alcohol dehydrogenase activity.

• How do the pharmacokinetic interactions of acute alcohol consumption differ from that of chronic alcohol consumption?

Acute alcohol consumption will be metabolised through the alcohol dehydrogenase pathway whereas chronic consumption will be metabolised through the MEOS pathway.

• Name 4 drug interactions with alcohol where the pharmacological effects of the other drugs are potentiated by alcohol.

Vasodilators 

Hypoglaecemic drugs 

Aspirin 

Disulfiram 

Metronidazole 

trimethoprim