BP

Question 1

Centrally acting antihypertensives

Answer 1

• Methyldopa: used in the management of hypertension during pregnancy
• Clonidine: the antihypertensive effect is mediated through stimulating alpha-2 adrenoceptors in the vasomotor centre

Both are central alpha-2 adrenergic agonis

Question 2

Drugs that can inadvertently elevate blood pressure

Answer 2

• NSAIDs
• Antidepressants (Tricyclics, doxepin)
• Steroids (Prednisone)
• Oral contraceptives
• Decongestants (Pseudoephedrine)
• Migraine medications (triptans, ergotamine)
• Erythropoietin

Question 3

Reasons for inaccurate BP measurement values

Answer 3

• Wrong cuff size: bladder too small: overestimation of BP. Bladder too large: underestimation of BP
• The arm should be horizontal at the level of the heart. Lowering of the arm below heart level: overestimation of BP. Elevation of the arm above heart level: underestimation of BP
• Posture: the sitting position is considered standard for routine BP measurement
• Arm support: if the arm is unsupported this may raise the diastolic blood pressure (as the arm is performing isometric exercise)

Question 4

Secondary causes of hypertension

Answer 4

• Renal causes: glomerulonephritis, pyelonephritis, adult polycystic kidney disease, renal artery stenosis
• Endocrine disorders: primary hyperaldosteronism, phaeochromocytoma, Cushing’s syndrome, Liddle’s syndrome, congenital adrenal hyperplasia (11-beta hydroxylase deficiency), acromegaly
• Drug causes: steroids, monoamine oxidase inhibitors, the combined oral contraceptive pill, NSAIDs, leflunomide
• Other causes include: pregnancy, coarctation of the aorta

Question 5

Causes of BP discrepancy between the arms or between the arms and legs

Answer 5

• Coarctation of aorta
• Patent ductus arteriosus
• Dissecting aortic aneurysm
• Arterial occlusion or stenosis of any cause
• Supravalvular aortic stenosis
• Thoracic outlet syndrome

Question 6

Non-selective α-blockers

Answer 6

• Phenoxybenzamine (oral only)
• Phentolamine (IV)

Question 7

Selective α1-blockers

Answer 7

• prazosin,
• terazosin
• doxazosin