Blog #5 (SU 3.1)

• What type of kinetics applies for alcohol in the body? Also, explain the clinical significance of this.​​​​

- The alcohol dehydrogenase system that metabolises alcohol by means of zero-order kinetics at a rate of 7-10g/hour. The clinical significance of this system is that only low to moderate amounts of alcohol can be metabolised by this system because there is a limited amount of the co-enzyme NAD that saturates the system.

- The mixed function oxidase system (MEOS) metabolises higher concentrations of alcohol (> than 100mg/dL). The clinical significance of this system is that with chronic alcohol users this system’s activity increases and is induced so more alcohol is metabolised per time unit and tolerance is created.

• Give a brief summary of the metabolic pathways of ethanol metabolism.

Ethanol is metabolised and acetaldehyde is formed as an end product. Acetaldehyde is converted by enzyme aldehyddehidrogenase (dependent on co-enzyme NAD) to acetate which is in turn converted to carbon dioxide and water and is excreted.

• Which drugs can affect this metabolism and what are the effects thereof?

1.  Disulfiram
2.  Metronidazole
3. Cephalosporins
4. Hypoglycaemic drugs

These drugs block the effects of the alcohol by inhibiting the metabolism of alcohol. Aldehyddehidrogenase’s activity is blocked and acetaldehyde builds up in the body because it is not converted to acetate.

Reference list

Brand, L. 2021. SU 3 Alcohols. https://efundi.nwu.ac.za/access/lessonbuilder/item/5557061/group/dd46f2da-d3be-402e-9ba7-2c5955cedd9d/English%20power%20point/English%20PP%202021/SU%203.pdf Date of access: 3 Mar. 2021. [PowerPoint presentation]