Pharmacology And Body Systems

Question 1

What is pharmacology?

Answer 1

The study of drugs and their interactions with living organisms.

Question 2

True or False: Pharmacodynamics is the study of how the body affects a drug.

Answer 2

False. Pharmacodynamics is the study of how drugs affect the body.

Question 3

Fill in the blank: Pharmacokinetics is the study of how the body __________ drugs.

Answer 3

Pharmacokinetics is the study of how the body absorbs, distributes, metabolizes, and excretes drugs.

Question 4

What is a drug receptor?

Answer 4

A protein molecule to which a drug binds to produce its effects.

Question 5

What is a drug agonist?

Answer 5

A drug that activates a receptor to produce a biological response.

Question 6

What is a drug antagonist?

Answer 6

A drug that blocks a receptor to prevent a biological response.

Question 7

What is a side effect of a drug?

Answer 7

An unintended effect of a drug that is not related to its therapeutic action.

Question 8

What is the placebo effect?

Answer 8

A beneficial effect produced by a placebo drug or treatment that cannot be attributed to its properties.

Question 9

What is a therapeutic index?

Answer 9

The ratio of the dose of a drug that causes toxicity to the dose that produces a clinically desired or effective response.

Question 10

True or False: Drug metabolism primarily occurs in the kidneys.

Answer 10

False. Drug metabolism primarily occurs in the liver.

Question 11

What is the main route of drug excretion from the body?

Answer 11

The kidneys, through urine.

Question 12

What is the blood-brain barrier?

Answer 12

A filtering mechanism in the blood vessels of the brain that prevents certain substances from entering the brain.

Question 13

What is the role of the autonomic nervous system in pharmacology?

Answer 13

Regulating involuntary bodily functions and influencing the effects of drugs on the body.

Question 14

What is the difference between sympathetic and parasympathetic nervous system responses?

Answer 14

Sympathetic responses prepare the body for fight or flight, while parasympathetic responses promote rest and digestion.

Question 15

What is the primary neurotransmitter of the sympathetic nervous system?

Answer 15

Norepinephrine.

Question 16

What is the primary neurotransmitter of the parasympathetic nervous system?

Answer 16

Acetylcholine.

Question 17

How do sympathomimetic drugs affect the body?

Answer 17

They mimic the effects of the sympathetic nervous system, such as increasing heart rate and blood pressure.

Question 18

What are common side effects of anticholinergic drugs?

Answer 18

Dry mouth, blurred vision, constipation, and urinary retention.

Question 19

What is the main function of beta-blockers?

Answer 19

To block the effects of adrenaline on beta receptors in the heart, reducing heart rate and blood pressure.

Question 20

What is the primary use of calcium channel blockers?

Answer 20

To relax and widen blood vessels, reducing blood pressure and increasing blood flow.

Question 21

True or False: Diuretics are drugs that increase sodium and water reabsorption in the kidneys.

Answer 21

False. Diuretics are drugs that increase urine production by the kidneys.

Question 22

What is the main mechanism of action of anticoagulant drugs?

Answer 22

To prevent blood clot formation by inhibiting the clotting process.

Question 23

What is the primary function of bronchodilator drugs?

Answer 23

To relax and widen the airways in the lungs, making breathing easier.

Question 24

What is the main purpose of analgesic drugs?

Answer 24

To relieve pain without causing loss of consciousness.

Question 25

Coronary artery disease (CAD)

Answer 25

Definition

Arteries that supply the heart muscle become hardened and narrow.

Processes at play

Atherosclerosis - Lesions form in the arteries which cause narrowing and loss of elasticity.

Hypercholesterolaemia - High cholesterol in the blood (lesions in the arteries are made of cholesterol and lipids and collagen).

Hypertension - High blood pressure when the pressure in arteries is constantly high and puts strain on the system.

Question 26

Heart failure

Answer 26

Definition
The heart (as a pump) is failing to meet the blood flow needs of the body.

Processes at play

Hypertension - With high blood pressure, the heart works harder to circulate blood; over time the heart muscle becomes thicker and eventually is too stiff to effectively pump blood.

Faulty heart valves - Valves ensure that the blood moves the correct way, if these do not work well the heart has to work harder.

Myocardial infarction - Over time, people with CAD may have an artery rupture, a blood clot forms and a section of the heart muscle becomes is damaged or may die.

Question 27

Cardiac dysrhythmias

Answer 27

Definition
Abnormalities in the rhythm of the heart associated with an impairment of the conduction system.

Processes at play

Atrial fibrillation (AF) - Rapid and irregular heart rhythm caused when atria quiver rather than pump. The atrial contractions are not coordinated with ventricular contractions.

Ventricular fibrillation (VF) - When contractions of the ventricles are disorganised and the ventricles quiver rather than pump. Is the most serious dysrhythmia as there is no effective cardiac output and will be fatal if untreated.

Question 28

Cardiac dysrhythmias

Answer 28

Definition
Abnormalities in the rhythm of the heart associated with an impairment of the conduction system.

Processes at play

Atrial fibrillation (AF) - Rapid and irregular heart rhythm caused when atria quiver rather than pump. The atrial contractions are not coordinated with ventricular contractions.

Ventricular fibrillation (VF) - When contractions of the ventricles are disorganised and the ventricles quiver rather than pump. Is the most serious dysrhythmia as there is no effective cardiac output and will be fatal if untreated.

Question 29

Cardiomyopathy

Answer 29

Definition
Condition in which the cardiac muscle becomes inflamed, enlarged and weakened.

Processes at play

Often unknown - Contributing factors are genetic conditions, hypertension, tachycardia, cardiac arrhythmias, alcoholism.

Question 30

Peripheral vascular disease (PVD)

Answer 30

Definition
Blood circulation disorder where vessels outside the heart narrow, block or spasm.

Processes at play

Atherosclerosis - Lesions form in the arteries which cause narrowing and loss of elasticity.

Hypercholesterolaemia - High cholesterol in the blood (lesions in the arteries are made of cholesterol and lipids and collagen).

Question 31

Cerebral vascular accident (CVA or stroke)

Answer 31

Definition
Blood flow to a part of the brain is stopped.

Processes at play

Ischaemic stroke - Arteries in brain become narrow or blocked, causing severely reduced blood flow. Underlying cause can be related to atherosclerosis and/or hypercholesterolaemia.

Haemorrhagic stroke - Blood vessel in brain leaks or ruptures.

Question 32

Severe hypoperfusion

Answer 32

Definition

A reduction in blood flow and the body tries to compensate by shutting down blood flow to the skin, visceral organs then heart and brain (peripheral to central shutdown)

Processes at play

Post cardiac arrest - Cardiac arrest occurs when the heart stops beating (e.g. as a result of ventricular fibrillation). If successfully treated, the heart may restart but the body may be in a state of hypoperfusion

Shock - A critical condition brought on by sudden drop in blood flow. May be secondary to blood loss (e.g. from trauma), severe infection (sepsis), anaphylaxis or other conditions (e.g. renal failure)

Question 33

Congenital heart defects

Answer 33

Definition

A general term for a range of birth defects that affect normal heart structure and/or functioning. (Examples below).

Processes at play

Atrial septal defect (ASD) - A hole in the septum between the atria of the heart. Oxygen-rich blood leaks from the left atrium into the right atrium.

Ventricular septal defect (VSD) - A hole in the septum between the ventricles of the heart. Oxygen-rich blood from the left ventricle is forced through the defect into the right ventricle.

Tetralogy of Fallot - A combination of four congenital heart defects. The four defects are a VSD, pulmonary stenosis, a misplaced aorta and right ventricular hypertrophy. They usually result in a lack of oxygen-rich blood reaching the body.

Question 34

Medications used for hypercholesterolaemia

Answer 34

Statins (Hypolipidaemic agents)
Medication examples: Generic (Trade) name

Atorvastatin (Lipitor)
Simvastatin (Lipex, Zocor)

Action

Act to lower cholesterol levels.
Does so by inhibiting a liver enzyme that is required to synthesis cholesterol and therefore lower the amount of circulating cholesterol in the blood (preventing formation of lesions).

Nursing responsibilities / Patient education
Patients should be advised to:

Take medication as a daily dose in the evening with food.
Have liver function tests every 4 to 6 weeks when dosage changed.
Contact doctor if experience:

very dark urine or yellowing of the eye sclera (as liver function may be affected)
muscle pain or muscle weakness (as inflammation of the muscles is a rare side effect).

Question 35

Medications used for hypertension

Answer 35

Hypertension refers to elevated blood pressure. Antihypertensives act to lower blood pressure and do so by interfering with the normal body regulatory systems of the nervous, endocrine, cardiac and renal system. A great way to learn the major groups of the antihypertensive medication is using the acronym A, B, C, D, & E.

Question 36

ACE inhibitors

Answer 36

ACE stands for Angiotension-converting enzyme

Medication examples: Generic name

Captopril
Enalapril
Perindopril
(Note: May end in “pril”)

Action

Act to lower blood pressure.
Do so by blocking the enzyme (angiotensin converting enzyme [ACE]) involved in the conversion of angiotensin I to angiotensin II. Allows blood vessels to relax and vasodilate.

Nursing responsibilities / Patient education

Monitor blood pressure before and after medication (as may drop blood pressure too low and cause dizziness).
Monitor potassium (K+) levels and renal function.

Question 37

Angiotensin receptor antagonists

Answer 37

ACE stands for Angiotension-converting enzyme

Medication examples: Generic name

Irbesartan,
Candesartan
Losartan

Action

Act to lower blood pressure.
Do so as antagonises angiotensin II receptors so that smooth muscles in the vascular do not constrict.

Nursing responsibilities / Patient education

Monitor blood pressure before and after medication (as may drop blood pressure too low and cause dizziness).

Question 38

Beta Blockers

Answer 38

Medication examples: Generic name

Atenolol
Carvedilol
Metoprolol
(Note: May end in “olol”)

Action

Act to lower blood pressure.
Are adrenergic antagonists and act by blocking the beta receptors on the heart muscle and reducing the effects of adrenaline, therefore heart beats slower and with less force.

Nursing responsibilities / Patient education

Monitor blood pressure before and after medication (may cause hypotension).
Monitor for other side effects (may cause cough, bradycardia, bronchospasm, sleep disturbances).

Question 39

Calcium channel antagonists

Answer 39

Medication examples: Generic (Trade) name

Nifedipine (Adalat)
Verapamil (Isoptin)

Action

Act to lower blood pressure.
Do so by decreasing availability of calcium within the heart, this relaxes smooth muscle and reduces heart contractions.

Nursing responsibilities / Patient education

Monitor pulse and blood pressure before and after medication (as may cause bradycardia and hypotension).
Patients should be advised to avoid grapefruit juice when taking medication.

Question 40

Diuretics

Answer 40

Types of diuretics

Thiazide diuretics e.g. Chlorothiazide (Dithiazide)
Loop diuretics e.g. Furosemide (Frusemide)
Potassium sparing diuretics: Spironolactone (Aldactone)

Thiazide diruetic - medication example:

Chlorothiazide

Act to lower blood pressure.
Do so by reducing blood volume; Inhibits the reabsorption of sodium, chloride and potassium ions, along with water, in the Loop of Henle.

Nursing responsibilities / Patient education

Monitor blood pressure before and after medication (may cause hypotension).
Monitor fluid balance and kidney function (may cause dehydration and kidney failure).
if taking a potassium depleting diuretic, patients should be advised to take potassium supplements as ordered.

Question 41

Endothelin receptor antagonists

Answer 41

Medication examples: Generic name

Ambrisentan (Volibris)
Bosentan (Tracleer)

Action

Act to lower blood pressure.
Do so by blocking endothelin receptors and blocking constriction of smooth muscles.

Nursing responsibilities / Patient education

Monitor blood pressure before and after medication (may cause hypotension).

Question 42

Medications used for cardiac tissue perfusion

Answer 42

Peripheral vasodilators

Medication examples: Generic name

Glyceryl trinitrate (GTN)
Isosorbide dintrate

Action

Acts to reduce workload on the heart by vasodilation of arteries and veins.
Can be prescribed for preventative (prophylactic) or therapeutic use.

Nursing responsibilities / Patient education

Monitor for excessive or cerebral vasodilation (may cause hypotension, headache, light headedness).

Question 43

Medications to treat cardiac arrhythmias and severe hypoperfusion

Answer 43

Antiarrhythmics are a group of medications used to treat ectopic (extra) heart beats and stabilise excitable myocardial tissue (Bullock & Manias, 2022). There are a few different medications in this group, but digoxin is the most common and is used to treat atrial fibrillation, which is experienced by approximately 5% of Australian adults over the age of 55 years (AIHW, 2020). Digoxin is also used in paediatric patients. As some arrhythmias (notably ventricular fibrillation) can lead to cardiac arrest, we include in this section agents used in emergency situations to manage severe hypoperfusion (e.g. adrenergic agonists such as adrenaline and dobutamine)

Question 44

Cardiac glycosides

Answer 44

Medication examples: Generic (Trade) name

Digoxin (Lanoxin)

Action

Cardiac inotrope: acts to increase the force of myocardial contraction and restore a normal, steady heart rhythm.
May be prescribed for atrial fibrillation, atrial flutter and cardiac failure.

Nursing responsibilities / Patient education

Can be administered orally or slowly, over at least 5 minutes, by an intravenous route.
Must monitor heart rate before administration. Withhold if < 60 beats/minute.
Has a narrow therapeutic index, so must monitor for toxicity e.g. nausea, vomiting, and blurred vision.
May interact with other medications (e.g. amiodarone)
In neonates and children, adhere to paediatric dosing guidelines and protocols.

Question 45

Antiarrythmics: Calcium channel antagonists

Answer 45

Medication examples

Verapamil (Isoptin)

Action

Calcium channel antagonist which inhibits atrio-ventricular (A-V) conduction
Used for the treatment of dysrhythmias (such as extra ventricular beats)

Nursing responsibilities

Must monitor cardiac response (BP, HR, ECG) and urinary output.
Withhold if patient has hypotension.
Educate patient to avoid grapefruit and its juice as these can increase verapamil serum levels.

Question 46

Antiarrythmics: Other

Question 47

Adrenergic agonists