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

Fast absorpsion and distrubusion, fastent person reaches peak after 30 min. Metabolism of ethanol is 90% by liver and rest through lungs and urine. Ethanol is eliminated through a zero-order kinetics (eliminates at a constant rate) so if a person ingests too much Ethanol it will lead to alcohol poisoning.

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

Ethanol is metabolized through two enzyme systems, Alcohol dehydrogenase for smaller amounts and Mixed function oxidase for larger concentrations. The end product after metabolism is acetaldehyde. Acetaldehyde is transformed to acetate with the help of Aldehyddehirdrogenase and is then converted to CO2 and H2O.

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

Disulfiram, Metronidazole, Hypoglycemics GM’s and Cephalosporins. These drugs blocks Aldehyddehidrogenase and causes an Acetaldehyde build up.

Natural/herbal medicines is a necessary alternative to rather try due to less side effects and none dependent factors. they due however interact with prescribed/OTC medicines and we as pharmacists should keep it in mind.

Herbal drugs for insomnia:

melatonin, Hops, chamomile, lemon balm etc

herbal drugs for anxiety:

cannabidol, lavender, chamomile, valerian etc,

What factors may affect the absorption and distribution of sedative-hypnotic drugs? What is the clinical significance thereof?

Lipophilic is the factor that plays the most important role in absorption and the time extent the drug will have an effect on the CNS. Drugs that has a low lipophilicy has a slow onset of effect because of the inability to cross the blood brain barrier. The more lipophilic the more effective the drug will be.

What is meant by redistribution and what is the significance thereof?

Redistribution happens when a drug is taken up into the circulation and transported to other tissue/parts of the body.

How are the BDs metabolized? Name the various steps in the process.

BD’s are metabolized by hepatic microsomal enzymes using 3 steps. (1) Dealkylation (2) Oxidation

(3) Conjugation

Which BDs are converted to active metabolites? What is the significance thereof?

Diazepam, Clorazepate, Prazepam, chloordiasepoksied and ketasolam. The ability to form active metabolites increases the effective time of medication.

Which BDs are not dependent on the cytochrome P450 oxidative enzymes for metabolism? What are the advantages thereof?

Oxazepam, Lorazepam, Temazepam, Lormetazepam. This medication is used when the patient’s cyto P450 activity is insufficient.

What is enzyme induction? Which of the sedative hypnotic drugs are known for this?. What is the clinical significance of enzyme induction?

Enzyme induction is when the enzymes is induced which will cause and increased metabolism of the drug. The drug concentration in the systemic circulation is less and will have a decrease in the therapeutic effect of the drug.

1. Which type of ion channels are found on the cell nerve membrane?

• ligand-gated channels 
• voltage-gated channels 

2. Name 3 differences between voltage gated and ligand-gated channels.

Voltage gated is indirect where ligand gated is direct.

Voltage gated changes the potential of the membrane of the cell where ligand gated channels binds to ion 

Voltage gated is channels for Sodium, Potassium and Calcium where with ligand the channels only opens when it is binded.

3. Compare ionotropic and metabotropic receptors.

Inotropic : the neurotransmitter binds to the ionotropic receptor which opens the ion channels. There is no second messangers involved in this process. 

Metabotropic: neurotransmitter binds to receptor and links a G-protein that activates second messangers that opens the ion channels. This effects last longer due to the G-protein that is involved.

4. Classify the CNS receptors into ionotropic and metabotropic and know the transduction mechanism of each receptor.

Metabotropic:

*Adenielsiklase:

• Beta 1 and beta 2
• D1
• D2
• mGlu 1
• M2 and M4
• Alpha 2
• 5-HT A and B

*Phospholipase:

• H1
• M1,3,5
• mGlu8
• Alpha 1
• 5-HT 2

Inotropic:

• Serotonin
• Ach
• Glutamate
• GABA

5. Explain the difference between an EPSP and an IPSP and give eg of each.

EPSP

1. Post synaptic potential activation
2. eg. Hyperpolarization takes place after the neurotransmitter binds to the GABA because of the open chloride channels 

IPSP

1. Inhibits the post synaptic potential
2. eg. Depolarization of the post synaptic potential takes place when the neurotransmitter binds to the glutamate receptor and the Sodium and Calcium channels open up.

6. What is the role of calcium in the development of a synaptic potential?

Calcium is needed to generate a potential via the calcium ion channels.