Drug Target Pharmacodynamics Flashcards
Question: How are drugs defined, and what is their primary purpose in a biological system?
Answer: Drugs are molecules that interact with a biological system to produce a biological response.
Question: What characterizes most drugs in terms of molecular weight and origin?
Answer: Most drugs are ‘small molecules’ with molecular weights less than 600 and are not endogenous.
Question: Provide examples of emerging therapeutic agents categorized as ‘biologics.’
Answer: More ‘biologics’ entering the clinic include antibodies and proteins as therapeutic agents.
Question: What is emphasized regarding drug safety, and what factor determines it?
Answer: No drug is entirely safe; the balance between efficacy and toxicity is crucial. Drug safety depends on its therapeutic index, which varies for all drugs, making the administration of the right dose essential.
Explain this graph
- This graph shows what happens to plasma concentration (mg/ml) over time (s) when a patient takes one tablet.
-The peak of the graph is when the drug is absorbed into the patient - The decrease shows the drug being removed from the system and gets metabolised until no drug is left.
- 2 dashed lines shown:
Bottom line is the minimum effective concentration
Top line is toxic concentration - Between the MEC and TC is the therapeutic window and this is the range of effective doses that can be given to a patient.
- The wider the therapeutic window the wider the range of doses that can be given to a patient.
- The narrower the therapeutic window, the narrower the range of dosages, thus more caution taken when giving doses of drug.
Question: What is the primary goal of administering drugs in the context of a biological response?
Answer: Drugs are administered to achieve a biological response that alleviates the symptoms or cause of an illness.
Question: What is responsible for producing symptoms or causing illnesses at a biological level?
Answer: A biological process is responsible for producing the symptoms or causing the illness.
Question: Describe the nature of a drug target at the molecular level.
Answer: At the molecular level, a drug target is usually a biomacromolecule such as a receptor, enzyme, or ion channel involved in the biological process.
Question: What happens when a drug molecule interacts with its molecular target?
Answer: The drug molecule interacts with the molecular target and produces a response that is clinically beneficial.
Question: Where is the drug target typically located, emphasizing its context in drug development?
Answer: The drug target is not in a test tube; it is buried somewhere in a physiological system, specifically within a patient.
Question: How do drugs get to their target?
Answer: - In terms of taking the drug orally, the drug enters the mouth then down into the stomach.
- Drug must find a way to not get broken down by the highly acidic stomach acid.
- Assuming it survived, the drug moves int small intestine.
- Small intestine has large surface area, provides maximum absorption.
- Drug is absorbed across the lipid membrane of GI tract and enters bloodstream.
- Drug must avoid absorption of reflux pump.
- If survived, the drug moves through the lipid membrane into the systematic circulation.
- Drug enters the portal vein which leads into the liver.
- Drug must avoid metabolism of the liver.
- If avoided, the drug circulates in the blood to find its target.
- In order for the drug to reach its site of action, it may need to diffuse across another lipophilic membrane.
Question: Name an example of a drug target enzyme involved in the inflammatory response.
Answer: Cyclo-oxygenase (COX) is an example of a drug target enzyme involved in the inflammatory response.
Question: What role does COX play in the synthesis of prostaglandins (PGs) during inflammation?
Answer: COX initiates the PG synthesis cascade by catalyzing the cyclization and oxidation of its substrate arachidonic acid (AA) at the site of inflammation.
Question: How do non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen and flurbiprofen affect COX?
Answer: NSAIDs are competitive inhibitors of COX, binding to the catalytic site. This prevents arachidonic acid (AA) from binding and being converted to PGs.
Question: What is the clinical consequence of inhibiting COX with NSAIDs?
Answer: Inhibiting COX with NSAIDs leads to a reduction in PG levels, resulting in a decrease in inflammation.
Question: Describe a potential side effect associated with the non-specific inhibition of COX in the stomach.
Answer: Non-specific inhibition of COX in the stomach reduces prostaglandin levels, making the stomach susceptible to ulceration, as high prostaglandin levels typically protect the stomach wall from degradation by acid.
Question: Identify an example of a drug target receptor involved in bronchial smooth muscle activation
Answer: β2 adrenoceptors are an example of drug target receptors involved in bronchial smooth muscle activation.
Question: What initiates the activation of β2 adrenoceptors in bronchial smooth muscle?
Answer: Activation of β2 adrenoceptors in bronchial smooth muscle is initiated by adrenaline and noradrenaline.