Asthma Drugs

Question 1

Beta 2 agonists:

2 types

Mechanism

Answer 1

SABA - short-acting
LABA - long-acting - help with morning dips and nocturnal symptoms

Stimulates beta 2 adrenergic receptors in the smooth muscle of airways
Causes smooth muscle relaxation via reducing Ca movement

Question 2

Beta 2 agonists:

Side effects:

• SE in the hands
• Why do they get tachycardia and palpitations?
• Psych - 1
• Head - 1
• Which type are muscle cramps common in?
• Why could they get hypokalaemia?

Answer 2

Tremor - complicated mechanism

Stimulation of sympathetic receptors in the heart

Anxiety

Headache

LABA

Decrease serum potassium levels via an inward shift of potassium into the cells due to an effect on the membrane-bound Na/K-ATPase, which can potentially result in hypokalemia

Question 3

Corticosteroids:

Hydrocortisone:

• What hormone does it contain?
• Why can this type be used therapeutically?

Prednisolone:
- How does the half-life compare to hydrocortisone?

Dexamethasone:
- Why is this one used more in oncology and intracranial conditions?

Withdrawal - how is it done?

Answer 3

Cortisone is an inactive metabolite of cortisol, but it can be converted back into cortisol

Cortisol

Longer half than cortisol

Tapering

Question 4

Corticosteroids:

Side effects of inhaled corticosteroids (ICS)? What can be done to avoid this?

Side effects of oral corticosteroids:

They can have Cushing’s syndrome. What appearance do they have?

Mneunomic CUSHINGOID

Answer 4

Oral candidiasis and dysphonia - rinse mouth after use

Moon face and striae - look in endocrine

C – Cataracts/glaucoma
U – Ulcers
S – Striae, Skin thinning
H – Hypertension, Hirsutism
I – Immunosuppression, Infections
N – Necrosis of femoral heads - cause unknown 
G – Glucose elevation
O – Osteoporosis, Obesity
I – Impaired wound healing
D – Depression/mood changes

Question 5

Corticosteroids - SE explained:

Why do they cause ulcers?

Why do they get hypertension?

Why do they get immunosuppression and infections?

Why do they get hyperglycaemia?

Why do they osteoporosis?

Why do they cause depression/mood changes?

CAN ALSO LOOK AT STEROIDS IN HAEMO

Answer 5

Both gastric mucus production and gastric bicarbonate secretion are impaired by steroid administration, therefore, more acid - MUST BE TAKEN WITH MEAL

Increased fluid retention - also the reason for weight gain

Steroids work by slowing your body’s response to disease or injury

It makes the liver insulin resistant

Reduce the body’s ability to absorb calcium and increase how fast bone is broken down.

Research suggests that corticosteroids lower serotonin levels in the body, and it is known that lowered serotonin levels can cause depression and other psychiatric disorders. Withdrawal from corticosteroids can also trigger depression.

CAN ALSO LOOK AT STEROIDS IN HAEMO

Question 6

Aminophylline:

What is this metabolised to?

What does it do?

Side effects:

• GI
• Cardiac
• Neurological
• What electrolyte becomes hypo?

Why are on this prone to side effects?

Answer 6

Decrease serum potassium levels via an inward shift of potassium into the cells due to an effect on the membrane-bound Na/K-ATPase, which can potentially result in hypokalemia - SAME AS BETA 2 agonists

Theophylline

Bronchodilation - same as beta 2 agonists

N&V
Arrhythmias
Seizures

There is a narrow therapeutic window

Question 7

Leukotriene receptor antagonists:

Examples - M, Z
MOA

Answer 7

Montelukast
Zafirlukast

Blocks CystLT receptor - reduces mucus secretion

Question 8

Anticholinergics:

Examples - I, T

MOA

What lung disease is it more beneficial in?

Answer 8

Ipratropium
Tiotropium

Reduces muscle spasm - bronchodilation

COPD