Steroids Flashcards

1
Q

What does the term respiratory disease mean?

A

Term given to diseases that affect organs and tissues involved in gaseous exchange.

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2
Q

What does the upper respiratory tract consist of?

A

Pharynx, nose and nasal cavity.

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3
Q

What does the lower respiratory tract consist of?

A

Larynx, trachea, bronchi and lungs.

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4
Q

What are steroids, what are their function?

A

Steroids are natural and synthetic compounds.
Have important physiological role in body for cell signaling.
Function as anti-inflammatory agents.

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5
Q

Describe steroid structure.

A

Characterised by 4 cycloalkane rings - 3 cyclohexane and 1 cyclopentane.
Variation obtained by different functional groups and oxidation state of rings.

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6
Q

Describe why endogenous steroids have an important biological role.

A

They’re present in lipid membranes.
Facilitates membrane fluidity (temperature dependent).
Controls membrane permeability

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7
Q

What is steroidogenesis?

A

Biological process by which endogenous steroids are generated from cholesterol.

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8
Q

Define hormone.

A

chemical messenger released by a cell/gland in one part of the body that can affect cells in another part of the body.

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9
Q

Where are corticosteroids produced? What are their functions?
(Includes glucocorticoids (cortisol) and mineralocorticoids (aldosterone))

A

Produced in the adrenal cortex.

Regulate immune function, stress response and metabolism.

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10
Q

Where are sex steroids produced? What are their functions?

Includes androgens (testosterone), oestrogens (estradiol) and progestogens (progesterone)

A

Produced by ovaries, testes and adrenal gland.
Interact with estrogen and androgen receptors.
Differentiate sex and supports reproduction.

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11
Q

Steroids decrease inflammation and activity of the immune system. In 2 simple sentences describe why.

A

Reduce production of inflammatory mediators (cytokines).

Alter the functioning of immune cells.

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12
Q

In asthma, there is inflammation of the airways and constriction of smooth muscle. How do steroids help with this?

A

Reduce inflammation and swelling in airways to restore airflow and to alleviate pressures in breathing

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13
Q

Give an example of a widely used anti-inflammatory drug.

A

Dexamethasone.

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14
Q

What conditions is dexamethasone used for?

A

Arthritis, cancer, colitis, allergies, asthma.

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15
Q

What is the MOA of dexamethasone?

A

Reduce vasodilation and permeability of blood vessels.
Regulates gene expression.
Dampens activation of immune system.
Stops pro-inflammatory cascade.

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16
Q

There is no benefit in using dexamethasone in less severe disease of COVID-19. Why does dexamethasone work best in severe patients?

A

Severe patients are on ventilation and given oxygen. Mechanical ventilation causes stress within body and stress upregulates expression of ACE2 - this allows entry of virus into the cell. Dexamethasone blocks this pathway, preventing increase in ACE2.

ACE2 = angiotensin converting enzyme 2.

17
Q

What is the general MOA of steroids? All steroids function the same way. Talk about interaction to entry into nucleus.

A

Steroid cross the plasma membrane and interacts with a steroid receptor.
Binding to receptor displaces a protein called chaperone e.g. HSO90.
Chaperone protein will keep receptor in correct place and facilitate receptor functioning.
Steroid-receptor complex then forms a dimer and enter nucleus of cell.

18
Q

Name 5 steroid drugs. Give type of formulation and route of administration.

A

Fluticasone propionate - inhaler - inhalation
Beclomethasone dipropionate - inhaler - inhalation
Budesonide - inhaler - inhalation
Prednisolone - tablet - oral
Hydrocortisone - injection - IV