Pharmacological Management of Hypertension Flashcards
What is the difference between primary and secondary hypertension?
-
Primary hypertension
- Idiopathic; unknown origin; >90% of cases.
-
Secondary hypertension
- Known cause; <10% of cases.
- Examples: renal disease, phaeochromocytoma, diabetes, Cushing’s, some drugs.
Differentiate between ‘low’ BP, normal BP, stage 1 and stage 2 hypertension.
What are the chances of harm due to hypertension?
- Depends on:
- How high the BP is
- How long the person has had high BP
- Whether any relevant concurrent health problems (such as high cholesterol or diabetes)
- Concordance with medication / lifestyle changes
What is hypertension a major risk factor for?
- Stroke
- MI
- Heart failure
- CKD
- Cognitive decline
- Premature death
- Untreated hypertension can cause cascular and renal damage leading to a treatment-resistance state.
What are the goals of hypertension treatment?
- Reduce arterial BP to recommended targets.
- Reduce risk of end organ damage (CV, renal, cerebrovascular).
- Reduce risk of mortality due to CV disease.
Describe the care pathway for hypertension.
What are the indications to prescribe for management of hypertension?
- Patients of any age with stage 2 or 3 hypertension.
- Patients with stage 1 hypertension who have one or more of the following:
- Target organ damage
- Established CV disease (CHD, CVA)
- Renal disease
- Diabetes
- 10-year CV risk equivalent to 20% or greater
What are the risk score calculators for estimating CV risk?
- ASSIGN
- Qrisk
- JBS3
- Based on:
- BP
- Age
- Weight/height
- Gender
- Smoking
- Cholestrol
- Ethnicity
- Social class
- Family history
- Diabetes, rheumatoid arthritis, renal function
What are the BP treatment targets?
- Standard patients
- <140/90mmHg
- Over 80 years of age
- <150/90mmHg
- More important than controlling BP is preventing falls. Do not drop BP too fast or too low.
- Cardiac / renal disease or diabetes
- <130/80mmHg
- BUT, make it patient centres:
- Individualised targets based on appropriateness, tolerability and frailty.
Before prescribing anti-hypertensive medication, you must review the patient’s drugs.
Which drugs cause a possible increase in BP?
- NSAIDs (e.g. ibuprofen, diclofenac)
- Oral steroids (e.g. Prednisolone)
- Venlafaxine (anti-depressant)
- Oral sympathomimetic decongestants (e.g. Pseudoephedrine - “Sudafed”)
- Soluble or dispersible drugs - contains SALT
- Illicit drug use.
What are the factors which regulate arterial BP?
- Cardiac output (CO) - HR, SV
- Total peripheral resistance (TPR) - or systemic vascular resistance.
- TPR x CO = MAP
Give a summary of the stepwise anti-hypertensive drug treatment.
What are the major classes of anti-hypertensive drugs?
- Renin-Angiotensin system inhibitors
- Calcium channel blockers
- Diuretics
Give examples of the Renin-Angiotensin system inhibitors.
- Angiotensin converting enzyme inhibitors (ACE inhibitors)
- Ramipril, lisinopril, captopril
- Angiotensin AT1 receptor antagonists (ARBs)
- Losartan, candesartan, irbesartan
Give examples of calcium channel blockers.
- Amlodipine
- Felodipine
- Lercanidipine
Give examples of the diuretics used in management of hypertension.
- Thiazide-like diuretics - often essential at step 2 or 3, but not effective in moderate-severe renal impairment.
- Indapamide, bendroflumethiazide
- High dose loop diuretics (e.g. Furosemide) may be used for raised BP in renal failure.
What are the additional treatments for resistant hypertension?
- Sympathetic nervous system antagonists
- β-blockers
- E.g. atenolol
- α1 adrenoceptor blockers
- E.g. doxazosin
- β-blockers
- Kidney function modifiers
- Potassium sparing diuretics and aldosterone antagonists
- E.g. amiloride, spironolactone
- Potassium sparing diuretics and aldosterone antagonists
Describe the parts of the pathway which ACE-Inhibitors and ARBs act upon to produce their anti-hypertensive effects.
What are the contraindications for prescribing ACE-I or ARBs?
- Allergy, hypersensitivity.
- History of angioneurotic oedema (hereditary, idiopathic or due to previous angioedema with ACE-I or ARBs).
- Significant bilateral renal artery stenosis or renal artery stenosis in a single functioning kidney.
- Pregnancy.