Treatment of blood pressure
Lifestyle modification of blood pressure patient
It has surely had a role in the prevention and treatment of hypertension and recommended for pre-hypertensive and adjuvant therapy. Modification ought to address cardiovascular risks, although these changes do not produce significant blood pressure reduction to cut down therapy.
| Weight reduction | Maintain BMI<25 kg/m2 |
| Salt reduction | <6 g NaCl/day |
| DASH diet | More fruits, vegetables , low fat dairy product |
| alcohol | <2 drinks/d men, <1 drinks/d in women |
| Physical activity | 30 min/day |
Reduction of obesity is an important risk factor for blood pressure treatment. In addition, every 10 kg losing weight will reduce 3 to 7 mmHg blood pressure, and 30 min brisk walking every week may get the benefit. foods to reduce high blood pressure is the DASH diet.
Drugs for high blood pressure
Lowering blood pressure surely reduces cardiovascular events such as 35-40 % for stroke,12-16% for coronary heart disease, and Heart failure >50 %. Antihypertensive drug selection depends on age severity, risk factors, comorbid condition, cost and side effects, and frequency of dosing.
Diuretic
| Diuretic thiazides | Hydrochlorthiazide, chlorthalidone | 6.25-50 mg 25-50 mg |
| Loop diuretic | Frusemide Ethacrynic acid | 40-80mg 50-100 mg |
| Aldosterone antagonist | Spironolactone eplerenone | 25-100 mg 50-100 mg |
| K retaining | Amiloride triamterene | 5-10 mg 50-100 mg |
Thiazide diuretic may be used alone or in combination with other blood pressure medication.it inhibit Na /Cl pump in distal convoluted tubule also safe, efficacious, cost-effective. In addition, thiazide provides additional benefits in combination with beta-blockers, ACE inhibitors, ARB.
Chlorthalidone and hydrochlorothiazide have a similar structure however chlorthalidone has a longer half-life(40-60 hr) and 1.5-2.0 times more potent. Potassium-sparing diuretic inhibiting ENaC in distal tubules and has weak antihypertensive properties but can be used to counteract hypokalemia. Loop diuretic reserved for reduced glomerular filtration, CHF.
Renin- angiotensin system blocker
ACE inhibitors decrease angiotensin 2, sympathetic system, and increase bradykinin where ARBs are selective angiotensin receptors 1 blocker(AT1 ). Both can be used alone or in combination with another agent, improve insulin sensitivity. Valsartan highly recommends blood pressure with the risk of developing diabetes.
| ACE inhibitors Captopril Lisinopril Ramipril | 25-200 mg 10-40 mg 2.5-20 mg |
| Angiotensin 2 inhibitors Losartan Valsartan candesartan | 25-100 mg 80-320 mg 2-32 mg |
| Renin-inhibitors aliskiren | 150-300 mg |
The main side effects are functional renal insufficiency, hyperkalemia, and worsen by dehydration, CHF, use of NSAIDs. Aliskiren is as effective as ACE and ARB but not considered a first-line blood pressure lowering agent.
Aldosterone antagonist
Spironolactone is a nonselective aldosterone antagonist and effective in low renin primary hypertension, resistance hypertension, and primary aldosteronism. It acts via progesterone and androgen receptors so side effects are gynecomastia, impotence, menstrual abnormalities.
Beta blocker
It lowers blood pressure by decreasing heart rate, cardiac contractility, and renin. May combined with a diuretic for better antihypertensive effects. Beta-blockers with intrinsic sympatholytic activity may lower cardiovascular risk, mortality and recurrent MI.CHF patients on beta-blocker showed decreased hospitalization rates. Labetalol and carvedilol blocks alpha and beta receptors in treating blood pressure remain to be determined. Nebivolol has the unique quality of vasodilation.
| Cardioselective Atenolol Metoprolol | 25-100 mg 25-100 mg |
| Nonselective Propranolol Propranolol LA | 40-160 mg 60-180 mg |
| Alpha + beta action Labetalol carvedilol | 200-800 mg 12.5-50 nmg |
Alpha adrenergic blockers for blood pressure
It acts on postsynaptic receptors antagonist and decreases peripheral vascular resistance. It does not reduce cardiovascular mortality. Selective alpha-blockers are used in prostate hypertrophy to alleviate urinary symptoms and nonselective is used in pheochromocytoma.
| Selective Prazosin Doxazosin Terazosin | 2-20 mg 1-16 mg 1-10 mg |
| Nonselective phenoxybenzamine | 20-120 mg |
Sympatholytic agent for blood pressure
Alpha 2 agonists decrease peripheral resistance by inhibiting sympathetic outflow. It may use in autonomic neuropathy due to baroreceptor denervation. Side effects are to decrease sleep, dry mouth, and rebound blood pressure, orthostatic hypotension, sexual dysfunction.
| Clonidine Methydopa Reserpine Guanfacine | 0.1-0.6 mg 250-1000 mg 0.05-0.25 mg 0.5-2 mg |
Calcium channel blockers for blood pressure
It reduces vascular resistance by L channel blockade so decrease calcium leads to no vasoconstriction. CCB can be used alone or combined with ACEI, BB, diuretic, etc. main side effects are flushing and edema.
| Dihydropyridine Nefedipine (long acting) Nondihydropyridine Verapamil Diltiazem | 30-60 mg 120-360 mg 180-420 mg |
Direct vasodilator for blood pressure
Vasodilator decreases peripheral resistance and resists a counter system that increases blood pressure. Use alone or in combination. Hydralazine is a potent vasodilator that has antioxidant and enhances nitric oxide level. Minoxidil mainly used in renal insufficiency and side effects is hypertrichosis and pericardial effusion. Intravenous nitroprusside may be used in the treatment of malignant hypertension and left ventricular heart failure.
| Hydralazine Minoxidil | 25-100 mg 2.5-80 mg |
Compare blood pressure medication
Most antihypertensive drugs reduce 8-10/4-7 mmHg although subgroups may differ. Young patients are more responsive to beta-blockers and ACE inhibitors where elderly patients are more responsive to diuretic and CCBs. You can treat patients on the basis of renin if the plasma level of renin is high so you can give ACE or ARB and if low renin then CCB and diuretic. A recent study shows metabolomic and gene profiles can guide treatment.
More then 30 randomized trial shows a reduction of blood pressure but a similar net effect on cardiovascular events even no difference between diabetic and nondiabetic.
Antihypertensive and lipid-lowering treatment to prevent heart attack trial (ALLHAT) showed CHD and overall mortality was virtually identical in blood pressure patients who treated with ACEI (Lisinopril), diuretic (chlorthalidone), or CCB (amlodipine). Beta-blockers are inferior to other class but CCB and diuretic are may be superior to others for the prevention of heart failure.
ACEI and ARB have additional effects on kidney, it decreases Intra glomerular pressure and protein also in the diabetic and nondiabetic patient so may decrease the rate of progression of renal insufficiency . among African American with hypertension induces renal disease, ACEI is more effective than beta-blockers and CCB.
Most patients with hypertension and heart failure, use of a diuretic, ACEI, or ARB, beta-blocker is recommended to good survival. ACEI gives good protection against coronary disease decrease left ventricular mass, improves symptoms, reduces mortality, and morbidity. For stroke prevention, CCB is better. ACCOMPLISH trial showed ACEI (benazepril) + CCB (amlodipine) is more superior than the combination of ACEI + diuretic ( hydrochlorothiazide) in reducing cardiovascular events.
Recent non-pharmacological antihypertensive therapy carotid baroreceptor activation by devices and sympathetic nerve of kidney ablation by radiofrequency has been suggested for resistant hypertension however trial showed no benefit after six months.
Blood pressure goals of antihypertensive therapy
Maximum protection against cardiovascular events achieved by reduced blood pressure <135-140 mmHg systolic and 80-85 mmHg diastolic although our aim is not just to achieve the target but reduce cardiovascular events.British blood pressure guidelines
More benefit is achieved by intense reduction of blood pressure <120 mmHg and The SPRINT trial showed reduces cardiovascular events and mortality by 25%. however, there are more chances to develop electrolyte imbalance, syncope. Australian blood pressure guideline
In diabetic patients, effective blood pressure reduces cardiovascular as well as microvascular complications. Action to control cardiovascular risk in diabetes clinical trial (ACCORD) showed no superiority of intensive blood pressure reduction <120 mmHg over standard control <140 mmHg. However, it does show a significant reduction in stroke and left ventricular hypertrophy.
Chronic renal insufficiency, more intensive blood pressure reduction leads to more damage to glomeruli and an increase in serum creatinine.so age >80 years should lower blood pressure more gradually e.g. 130-150 mmHg.
Tree or more drugs are required with diabetes and renal insufficiency patients and need 20% or less dosage is required for the reduction of hypertension.
Resistant blood pressure is defined by persistently high blood pressure < 140/90 mmHg despite taking three or more drugs including a diuretic. In this difficult situation look for pseudo hypertension and secondary hypertension.
blood pressure emergency
how to lower blood pressure in a minute? Overall availability of antihypertensive drugs reduces hypertensive emergency and rests presented with high blood pressure that is chronic high blood pressure patients. In the emergency, we should differentiate between hypertensive emergency vs hypertensive urgency. High blood pressure with end-organ damage called hypertensive emergency.
| Nitroprusside | 2-4 microgram/min |
| Nicardipine | 5mg /hr |
| Labetolol | 2 mg/min |
| Enalapril | 0.625-1.25 mg |
Malignant hypertension is defined by a sudden increase in blood pressure in previously normotensive individuals. Causes are necrotizing vasculitis, arterial thrombosis, fibrin deposit and clinically recognized by retinopathy, deteriorating renal function, proteinuria, microangiopathic hemolytic anemia, and encephalopathy.
how to lower blood pressure on the spot? Blood pressure should not reduce suddenly because of cerebral autoregulation that regulates cerebral circulation. If a sudden fall in blood pressure may develop cerebral, renal, and coronary ischemia so our target is a 25% reduction of blood pressure in the first 2 hours.
Cerebrovascular accident is mostly either ischemic or hemorrhagic then target blood pressure are different. if patients with ischemia and non-thrombolytic our targe should <185/110 mmHg. In hemorrhagic stroke more aggressive target 140-179 mmHg and in subarachnoid hemorrhage >130mmhg.
You can also read my blog on diabetes.
Thank you for reading my blog and valuable time.
There is a small test for you click below button
Dr Manish Khokhar
MD
Comments
Post a Comment
Thank you for your comments.