Pulmonary oedema

Question 1

Diclofenac

Mechanism of action?

Answer 1

NSAID
Non-selective COX inhibitor, hence reduces actions of COX1 and COX2.
It inhibits prostaglandin pathway through COX but it activates the 5-lipooxygenase pathway with leukotriene production. This increases vascular permeability and constriction of bronchial smooth muscles.

Question 2

Diclofenac

Side effects?

Answer 2

GIT: dyspepsia, GI bleeding, gastritis 
Renal: acute renal failure due to vasoconstriction, electrolyte imbalances
CVS: bleeding, MI and stroke 
Resp: bronchospasm
Haem: reduced PLT aggregation 
Anaphylaxis and skin rashes

Question 3

Diclofenac

Contraindications?

Answer 3

• Hypersensitivity to NSAIDs
• Known asthmatic or aspirin sensitive
• Third trimester pregnancy
• Previous history of GI bleeding
• Hepatic or renal failure
• Take care in IBD patients

Question 4

Metoprolol

Mechanism of action?

Answer 4

Beta-1 selective antagonist.
Primarily expressed in the heart, decreasing heart rate (chronotropic effect) and heart contractility (ionotropic effect).

Question 5

Metoprolol

Side effects?

Answer 5

Bradycardia 
Decreased exercise tolerance 
Heart failure
Hypotension 
Heart block

Question 6

Metoprolol

Contraindications?

Answer 6

• Sinus bradycardia or heart block patients
• Contraindicated in patients with asthma
• Contraindicated co-use with ACEI or ARB

Question 7

Quinapril

Class and mechanism of action?

Answer 7

ACE inhibitor.
Inhibits activity of angiotensin converting enzyme (ACE) expressed in lung and renal endothelium.

It decreases angiotensin 2 effects of:

• Increased sympathetic activity
• Increased sodium and water retention
• ADH and aldosterone release
• Systemic vasoconstriction

Question 8

ACEI

Side effects?

Answer 8

• Chronic dry cough related to the bradykinin released in the lung
• Angioedema
• Teratogen
• Hyperkalaemia
• Orthostatic HTN
• Proteinuria
• Renal/hepatic impairment

Question 9

ACEI

Contraindications

Answer 9

Pregnancy, hypersensitivity, renal stenosis, previous angioedema with ACEI therapy

Question 10

Digoxin

Class and mechanism of action?

Answer 10

Cardiac glycoside.
Inhibits Na/K/ATPase pump in cardiac myocytes. This causes increased sodium levels in cardiac myocytes leading to increased 3Na/Ca exchanger. Therefore increases intracellular calcium, and increases contractility and lengthening of cardiac action in phases 0 and 4, slowing heart rate – ionotropy but decreased chronotropy.

Question 11

Digoxin

Side effects?

Answer 11

Fatigue, nausea, vomiting, anorexia, headache, weakness, blurry vision, drowsiness, confusion, SA/AV block, electrolyte disturbance