Question

t. Provide TWO (2) arguments as to why this antibacterial should only be available with a doctor's prescription. (5 marks) Question 4 Recommended time - 20 min Addiction to drugs con coeur due to psychological and/or physical dependence. a Discuss the factors that underlie physical and psychological dependence, explaining the role each plays in addiction. (8 min) b. Compare and contrast the addictive potential of cocaine, LSD and morphine, using your response to (1) and the mechanisms of action of each of these drugs. Clearly indicate (with justification) which of the 3 drugs will be most addictive and which will be least addictive. (12 min) Question 5 Recommended time = 20 min The histamine H2 receptor was identified as a major stimulus for the secretion of gastric acid. As part of a program to develop drugs to treat gastric ulcers, scientists synthesised a series of histamine-based molecules and tested them for antagonist activity at the histamine Ha-receptor. Further modifications to the structures were made to increase effectiveness and selectivity. This program eventually led to the development of drugs such as ranitidine, which is currently used to decrease gastric acid secretion. a. From the information provided, identify the method of drug discovery for the histamine Hantagonists such as ranitadine. Provide an explanation for your answer (3 marks) b. Pick ONE other method of drug discovery and explain how it is used to discover drugs, indicating ONE drug that was discovered by this method. (6 marks) c. Describe the stages of development that must be undertaken before the drug will be tested in humans, highlighting what is involved in each and the information that is be gained from each stage. (6 marks) d. Identify and explain ONE (1) reason why the drug may not ever get to market despite promising results in the animal studies. (5 marks) e. Which government body is responsible for giving approval for a drug to be marketed in Australia? (1 mark)

Answer 1

4(a) The factor underlie physical and psychological dependence are

• Most stimulants, including cocaine and Ritalin
• Most hallucinogenic drugs, such as LSD
• Cannabis products (although there is mounting evidence that there may be a significant physical process of withdrawal that occurs in chronic users of cannabis products)
• Many inhalant products
• Many psychotropic medications, such as antidepressant medications

Substances with the development of strong physical dependence typically include:

• Alcohol
• Opiate drugs, such as heroin, morphine, Vicodin, etc.
• Benzodiazepines, such as Xanax, Valium, Ativan, etc.
• Barbiturates, such as Seconal and phenobarbital.

Before splitting addiction out into physical and psychological addiction, it is helpful to understand what addiction is as an umbrella term. When people talk about addiction, it means the continued use of a substance that alters a person’s mood in spite of negative consequences/behaviors.

To understand what addiction is, you need to be aware of the difference between physical and psychological addiction as well as tolerance and dependence

psychological warning signs to look out for:

• Memory loss
• Blackouts
• Mood swings
• Depression
• Irritability
• Headaches
• Seizures
• Nausea
• Vomiting
• Disorientation
• Shortness of breath
• Dry mouth
• Constricted pupils
• Body aches
• Pulse rate changes
• Blood pressure changes
• Tremors and shaking
• Restless legs

  Cravings are a key factor in psychological addictions, so it’s important for you to understand what they are. A craving is an intense desire for something and is one of the hallmarks of psychological dependence.

  If you try to stop your addiction, or even just cut down on your drug use, you’ll experience cravings. These can be so intense that they completely take over your life, and potentially significantly reduce your ability to think straight or focus on other areas of your life, like your job, education or relationships.

  Generally speaking, cravings don’t last for long. However, they can be very upsetting, and may even lead you back down the road to relapse.