Pharmacodynamics Flashcards
What is pharmacodynamics?
Relationship between drug concentration and intensity of action at the receptor level
What do drugs act on?
Most drugs act via an interaction with certain proteins either of the host or of the pathogen
What are the four types of protein are targeted by drugs:?
- Enzymes
- Carriers (transporters)
- Ion channels
- Receptors
When should the term receptor be used?
The term receptor is only used when the interaction triggers a cascade of events for signal transmission
First, the drug molecule and its _____ must interact.
The selective interaction must result in a response = ?
target, Lock and Key
Drug responses more commonly reflect the interaction of the drug, acting as a _____,
with receptor
ligand
What is a drug?
Drug is a molecule that interacts with specific molecular components of an organism to produce biochemical and physiological changes/effects
What are characteristics of drugs/ other terms used to describe them?
- Any chemical that can affect living processes
- Drugs can prevent, mitigate, diagnose or treat disease (pharmacotherapeutics)
- It could be a prescription or over the counter (OTC) drug
- Drugs may be viewed as exogenous ligands
What are the types of drug targets?
- receptors, enzymes, transporters, ion channels.

What is the target for NSAIDs? What does their inhibition cause?
yclooxygenases are the target site for NSAIDs and their inhibition leads to the suppression of
proinflammatory prostaglandins
What is the target site for cholinersterase inhibitors?
• Acetylcholinesterase (metabolizes acetylcholine), is a target site for cholinesterase inhibitors e. g., neostigmine and physostigmine
How may antibiotics work with enzymes?
Antibiotics may act by inhibiting enzymes involved in cell wall biosynthesis, nucleic acid metabolism and repair, or protein synthesis
Enzyme as a Target: Cyclooxygenase-1 and 2

Non-steroidal antiinflammatory drugs (NSAIDs) block the ________-_ and __ and stop thereby the synthesis of _________.
cyclooxygenase-1, 2, prostaglandins
Enzyme as a Target: Acetylcholinesterase (AChE)
What is AChE? How does it work?
cAChE is a cholinergic enzyme primarily found at postsynaptic neuromuscular junctions, especially in muscles and nerves. AChE breaks down acetylcholine (ACh) into acetic acid and choline. The primary role of AChE is to terminate neuronal transmission and signaling between synapses to prevent ACh dispersal and activation of nearby receptors
What are carriers? How so they work? What are examples?
- Carriers, also termed membrane transport proteins are target sites for many drugs
- The Na+/K+/2Cl- symport in the nephron is the site of action of furosemide and other diuretics such as torasemide. The biophase (effect site) for all diuretics is the urine, not plasma to develop their diuretic action
- Sodium pump Na+/K+ AT Pa s e , AT P- p o w e re d ion pumps, are the target sites for cardioactive digitalis
- The K+/H+ pump in the gastric parietal cells is the target site for proton pump inhibitors such as omeprazole
What carriers in the nephron are the site of action for furosemide? What other drugs can also utilize this path?
The Na+/K+/2Cl- symport in the nephron is the site of action of furosemide and other diuretics such as torasemide. The biophase (effect site) for all diuretics is the urine, not plasma to develop
their diuretic action
What are the target sites for cardioactive digitalis? What about omeprazole
• Sodium pump Na+/K+ AT Pa s e , AT P- p o w e re d ion pumps, are the target sites for cardioactive
digitalis • The K+/H+ pump in the gastric parietal cells is the target site for proton pump inhibitors such as
omeprazole
What is the molecular target of cardic glycosides? What is the purpose of these gradients?
The molecular target of cardiac glycosides is the Na+/K+ ATPase, which maintains sodium and potassium gradients across the plasma membrane. Those gradients are required for the regulation of cell volume, active transport of molecules or the creation and propagation of the action or resting potential of electrically excitable cells such as cardiac cells
What carriers do furosemide and bumetanide block? What does this cause?
The diuretics furosemide and bumetanide block the NKCC carrier (sodium, potassium, 2 chloride carrier aka BSC = bumetanide-sensitive carrier) causing a decrease in NaCl reabsorption and a concomitant increase in water elimination by the kidneys
What does omeprazole block? What does this cause?
Omeprazole blocks the activity of the H+/K+ ATPase in the parietal cells of the stomach reducing the secretion of protons and the formation of hydrochloric acid (HCl)
What is the main target of most calcium channel blockers like antiarrhythmic drug verapamil?
• Voltage-dependent gated calcium channels are the main target of the most calcium-channel
blockers, such as the antiarrhythmic drugs verapamil
What drugs typically block ion channels located on the membrane of the cardiac cells? How does this work?
Several antiarrhythmic drugs block ion channels located on the membrane of cardiac cells, thereby altering the cardiac action potential or its generation or propagation. This results in changes of the spread of activation or the pattern of repolarization. Thereby, these drugs suppress cardiac arrhythmia








