Pharmacology of Cardiovascular Drugs

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Questions and Answers

What effect do beta blockers have on heart rate and contractility?

Decrease heart rate and inotropy (correct)

Increase heart rate and contractility

Increase contractility while decreasing heart rate

Have no effect on heart rate

Which type of drug is phentolamine classified as?

Alpha blocker (correct)

Beta blocker

Adrenergic agonist

Vasodilator

Which adrenergic agonist is commonly mentioned for use in cardiac arrest?

Epinephrine (correct)

Dopamine

Norepinephrine

Isoproterenol

Which characteristic distinguishes selective beta blockers from non-selective beta blockers?

Selective beta blockers only block one type of beta receptor Signup and view all the answers

What is the primary use of adrenergic antagonists in medical treatment?

To block adrenergic receptor stimulation Signup and view all the answers

What is the primary use of Atropine in the context of symptomatic bradycardia?

Increasing heart rate Signup and view all the answers

Which drug category does Diazepam belong to?

Benzodiazepines Signup and view all the answers

What are common side effects of opioid use?

Drowsiness and respiratory depression Signup and view all the answers

What class of drugs does paracetamol fall under?

Antipyretics Signup and view all the answers

What is the approximate onset time for the action of Barbiturates?

Within 1-5 minutes Signup and view all the answers

What is the primary neurotransmitter at the synapses between parasympathetic postganglionic neurons and their effector cells?

Acetylcholine Signup and view all the answers

Which neurotransmitter is primarily involved in sympathetic postganglionic neuron-efffector cell synapses in most tissues?

Norepinephrine Signup and view all the answers

Which of the following is NOT typically a neurotransmitter involved in the actions of therapeutically useful drugs?

Acetate Signup and view all the answers

What is the role of dopamine in renal blood vessels?

It acts as a vasodilator. Signup and view all the answers

Which division of the nervous system is primarily responsible for the 'rest and digest' response?

Parasympathetic nervous system Signup and view all the answers

Which type of receptors are affected by cholinergic transmission?

Cholinergic receptors Signup and view all the answers

Which of the following substances is specifically released by sympathetic fibers to thermoregulatory sweat glands?

Acetylcholine Signup and view all the answers

What distinguishes sympathetic and parasympathetic nervous system actions?

Parasympathetic is associated with restorative functions. Signup and view all the answers

Which type of receptors are activated by acetylcholine (ACh)?

Muscarinic receptors Signup and view all the answers

What is the primary difference between the sympathetic and parasympathetic nervous systems regarding receptor types?

PNS is primarily cholinergic while SNS is adrenergic. Signup and view all the answers

What effect do adrenergic antagonists have on the body?

They block adrenergic receptors. Signup and view all the answers

Which adrenergic receptor type is involved with the action of catecholamines?

Alpha receptors Signup and view all the answers

Which neurotransmitter is NOT considered a cholinergic agent?

Norepinephrine Signup and view all the answers

What term describes drugs that stimulate cholinergic receptors?

Cholinergic agonists Signup and view all the answers

What is the role of nicotinic receptors?

They activate skeletal muscles. Signup and view all the answers

Which statement correctly describes the function of anticholinergic drugs?

They decrease secretion in the body. Signup and view all the answers

Which adrenergic antagonist is known to selectively block β receptors?

Selective β blocker Signup and view all the answers

What is a primary effect of cholinergic drugs on the body?

Decrease heart rate Signup and view all the answers

In what situation is atropine commonly used as a prehospital drug?

To manage bradycardia Signup and view all the answers

Which of the following describes the effect of nonselective adrenergic antagonists?

They can influence both α and β receptors. Signup and view all the answers

What is a significant risk when administering nonselective adrenergic antagonists to patients with asthma?

Bronchoconstriction Signup and view all the answers

What characteristic of a nonselective β blocker could potentially cause bradycardia?

It decreases myocardial contractility. Signup and view all the answers

Which of the following is a side effect of cholinergic agonists?

Increased secretion Signup and view all the answers

In the event of organophosphate poisoning, which drug is considered the first line of treatment?

Atropine Signup and view all the answers

Study Notes

Drugs Affecting the Nervous System

Module 6 covers drugs that impact the nervous system.

Autonomic Pharmacology

The nervous system is divided into peripheral and central nervous systems.
The peripheral system further branches into efferent and afferent divisions.
The efferent division, including the autonomic system, controls involuntary functions. Its branches involved are the parasympathetic nervous system (PNS) and sympathetic nervous system (SNS). SNS is responsible for "fight or flight" responses, while PNS handles "rest and digest."
Somatic system, part of the efferent division, handles voluntary functions.
The enteric nervous system is part of the peripheral nervous system, and controls the intestines.
The central nervous system connects to the peripheral system through nerves connecting the brain and spinal cord to the rest of the body.

Actions of Sympathetic and Parasympathetic Nervous Systems on Effector Organs

Sympathetic and parasympathetic responses often oppose each other to maintain homeostasis.
Effector organs such as the eye, glands, heart, kidney, ureters, bladder, and genitalia respond differently to sympathetic or parasympathetic stimulation.
Red indicates sympathetic responses, and blue shows parasympathetic responses.

Fight or Flight Response vs. Rest and Digest Stimulus

Sympathetic output (fight-or-flight) is diffuse, affecting multiple organs simultaneously.
Parasympathetic output (rest-and-digest) targets specific organs.

Sympathetic vs. Parasympathetic Nervous Systems

Homeostasis in the autonomic nervous system is dynamic, balancing sympathetic and parasympathetic activities.

Neuron

Neurons are nerve cells that communicate through synaptic signaling.
The cell body is the neuron's main part.
The axon is a long extension that transmits signals.
Dendrites receive signals.
Myelin sheaths cover axons for faster signal transmission.
Neurotransmitters are specialized chemicals released at axon terminals affecting target cells.

Types of Neurotransmitters

Many neurotransmitters exist, but norepinephrine, epinephrine, acetylcholine, dopamine, serotonin, histamine, glutamate, and GABA are most commonly involved in drug therapies.
Each neurotransmitter binds to specific receptors.

Cholinergic Transmission

Acetylcholine (ACh) is the primary neurotransmitter released at autonomic ganglia, in parasympathetic postganglionic synapses, and at the somatic neuromuscular junction, as well as some sympathetic postganglionic responses relating to sweat glands.

Adrenergic Transmission

Norepinephrine (NE) is the primary neurotransmitter at most sympathetic postganglionic neuron-effector cell synapses in the body, while some exceptions exist, like to sweat glands and possibly some vascular regions of skeletal muscle which respond to acetylcholine,
Dopamine can act as a vasodilator in some blood vessels.

Motor Fiber Diagram

ACh releases at many relevant locations.
Adrenergic responses occur further in effector organs.
The preganglionic and postganglionic neurons operate using ACh, but differ according to the action or response.

Efferent Organ Responses (Adrenergic and Cholinergic)

Adrenergic and cholinergic responses differ in their effects on various organs, e.g., heart rate, blood vessel constriction/dilation, and gland secretion.
Some organs have mixed sympathetic and parasympathetic input, resulting in varied responses depending on the dominant system's activity.

Drugs Affecting the ANS

Drugs can be agonists or antagonists, impacting sympathetic or parasympathetic activity.

Adrenergic Agonists (Sympathomimetic Drugs)

Norepinephrine and epinephrine are common sympathomimetic drugs used for their vasoconstrictive effects and in critical situations.
Albuterol is a beta2-agonist used to dilate bronchi and is often prescribed for asthma.
Dopamine is a potent sympathomimetic drug used to improve blood pressure.

Adrenergic Antagonists (Sympatholytic Drugs)

Phentolamine blocks alpha receptors, used when norepinephrine or other sympathetic neurotransmitters leak into tissue.
Beta blockers treat high blood pressure or cardiac issues and block beta receptors. Selective agents block specifically beta 1 or beta 2 receptors, while non-selective agents block both.

Cholinergic Agonists (Parasympathomimetic Drugs)

Physostigmine can counteract the effects of atropine or in poisoning. It elevates ACh function.
ACh agonists affect many involuntary processes.

Cholinergic Antagonists (Parasympatholytic Drugs)

Atropine is a cholinergic antagonist that increases heart rate, reduces secretions.

CNS Stimulants

Amphetamines, methamphetamine, dextroamphetamine, methylphenidate, and methylxanthines are CNS stimulants.
The effects (both good and bad) of these stimulants vary and are specific to the drug in question and the individual response.

Anti-anxiety & Sedative-hypnotic Drugs

Barbiturates and benzodiazepines are used for sedation, promotion of sleep, and anxiety reduction
CNS function is decreased with the consumption of these drugs.

Analgesics

These drugs decrease pain sensation.
Opioids (e.g., morphine) act on endorphin receptors, including mu and kappa.
Non-opioids (e.g., aspirin, ibuprofen) inhibit Cox enzymes.
Acetaminophen does not have peripheral side effects.
NSAIDs (non-steroidal anti-inflammatory drugs) like ibuprofen and aspirin are used to reduce pain and inflammation.

Anesthetics

These drugs cause loss of sensation, often consciousness.
Local anesthetics, lidocaine, affect a specific area, usually accompanied by epinephrine.

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Description

Test your knowledge on the effects of beta blockers, adrenergic agonists, and antagonists in medical treatment. This quiz covers essential pharmacological concepts related to cardiovascular drugs, including their uses and classifications. Perfect for students and professionals in the medical field.