Hypertension

Notes
  • Hypertension is defined as sustained elevation of resting systolic BP (≥ 140 mm Hg), diastolic BP (≥ 90 mm Hg), or both that is replicated in 3 separate readings.
  • Vital statistics of hypertension: global prevalence for adults above 25yrs = 40% (46% in African); prevalence among those above 65yrs = 66.6%; mortality rate due to hypertension = 12.8%.
  • There are two types of hypertension: primary or essential hypertension hypertention (consisting of 85-95% of cases) with unknown cause(s) and secondary hypertention with known cause(s).
  • Primary hypertension is most likely caused by multiple factors that include: genetic predisposition, defect of the ion pumps on sarcolemal membranes of vascular smooth muscle, high sodium intake, obesity, stress etc.
  • Secondary hypertension is caused by the following: medicines such as steroids, NSAIDS and sympathomimetics; renal diseases; Cushing syndrome; hyperthyroidism; pheochromocytoma, coarctation of aorta; myxedema and alcoholism among others.
  • The blood pressure readings are classified as indicated in the following table:

 

Classes

Systolic (mmHg)

Diastolic

(mmHg)

Hypotension

≤ 90

≤ 60

Normal

90-120     and

60-80

Prehypertension

(High-normal)

120-139  or

80-89

Stage 1 hypertension

(Mild)

140-159

90-99

Stage 2 hypertension

(Moderate)

160-179

100 -109

Stage 3 hypertension

(Severe)

> 180

> 110

Hypertensive crisis

 

> 120**

**With evidence of papilloedema, renal and neurological dysfunctions

Symptoms
  • The bulk of the hypertensive cases are asymptomatic.
  • The early symptoms of hypertension with early mild complications include: occipital headache and dizziness (especially early in the morning), epistaxis, fatigue and nervousness.
  • Most of the times, hypertension is asymptomatic until the end organs (mainly the kidney, cardiovascular system, brain and the retina) are affected by arteriolosclerosis. This can lead to hemorrhagic stroke, renal failure, coronary artery disease, hypertensive encephalopathy, myocardio infarction, heart failure and death.
Management
  1. Therapeutics guided by the Essen tial Drug List consideration
  • Non-pharmacological interventions: low salt diet; low fat diet; weight reduction in case of obesity; regular exercises and cessation of smoking.

 

  • Interventions

*Stage 1 hypertension: Non-pharmacological          interventions for 4-6 months; if no satisfactory response after this period institute monotherapy with a thiazide diuretic (nomally hydrochlorthiazide 25-50mg orally OD) or  ACE inhibitors (normally enalapril in case of diabetes).

 

*Stage 2 hypertension: Non-pharmacological  and pharmacological interventions used together; start with thiazide diuretic (normal      ly hydrochlorthiazide 25-50mg orally OD) for 4-6 wks and monitor. If the response is              not satisfactory add atenolol 50mg (but   contra-indicated in asthma or COPD) and increase gradually to 100mg for up to 6-8 wks. Consider other combinations in case of unsatisfactory results.

 

*Hypertensive crisis: Admit; the goal is to achieve diastolic BP of 100-110 mm Hg (but avoid                rapid drop of BP as cerebral hypoperfusion may occur). Two approaches are     considered:

 

**Approach A:furosemide 40mg             IV plus hydralazine 10mg IV repeated at an interval of 15 minutes until the goal is achieved or the dose of 50mg of hydralazine is reached. The total dose can repeated after 6 hrs or  sodium nitroprusside 0.25mg-10mg /kg/minute IV infusion.

**Approach B: oral nifedipine 20mg hourly. After controlling the BP administer: hydrochlorthiazide plus atenolol plus hydralazine or nifedipine or methyldopa or captopril.

 

  • Antihypertensives in the Essential Drug List:

*Amlodipine 5mg tablets

*Hydrochlorthiazide 25mg tablets

*Atenolol 50mg tablets

*Enalapril 25mg tablets

*Hydralazine injection 20mg /2ml [for use

*only in the pregnancy induced severe hypertension]

*Methyldopa 250mg tablets [restricted for use in the pregnancy induced hypertension]

*Sodium Niroprusside 50mg amp

 

  • Standard doses of Antihypertensives in the Essential Drug List

*Amlodipine: Dose: Hypertension or Angina, initially 5mg OD [max 10mg daily]

*Hydrochlorthiazide: 25-50mg OD

*Atenolol: 50mg daily [some authorities consider higher doses unnecessary].

*Enalapril: 5mg daily initially [max. 40mg daily].

   *Hydralazine: Slow IV: 5-10mg over 10. May be repeated after 20-30 minutes minutes.

*Methyldopa: Dose: Starting dose: 250mg BD or TID x 2/7 adjust until the desired effect is achieved.  Max. 3g daily. Children 10mg/kg daily in 2-4 doses [max. 65mg/kg or 3g daily whichever is less]. To minimize sedation, start dosage increases in the evening. When methyldopa tablets are added to a thiazide, the dosage of thiazide need not be changed. When methyldopa is given with other antihypertensives apart from thiazides for initial therapy the dosage of methyldopa should not exceed 500mg daily. After withdrawal of methyldopa, hypertension returns after 48 hours.

*Sodium niroprusside: start with 0.3 mcg/kg/min with upward titration every few minutes until the desired effect is achieved or the maximum recommended infusion rate of 10 mcg/kg/min has been reached.

 

  • Therapeutics using drugs that are NOT in the Essential Drug List

 

*In general, blacks respond better to diuretics and calcium channel blockers and less well to beta-blockers and ACE inhibitors than white.

 

*Treatment goal of hypertension

**For all patients target BP below 140/90             mm H

*For patients 60 yrs old and above target BP below 150/90 mm Hg

**Targetting PB close to 120/80 poses the risk of worsening of renal functions, dizziness and light-headedness.

 

*General algorithm of management of BP

**Initiate non-pharmacologic interventions

**For all patients with chronic renal disease (Blacks or Non-blacks): ACE inhibitors or ARBs alone or combined with other antihypertensives.

**Initially, for Blacks without chronic renal disease: titrate thiazide-like diuretics, calcium channel blockers (CCBs) alone or combined.

**Initially, for Non-blacks without chronic renal disease: titrate thiazide-like diuretics, ACE inhibitor, ARBs, calcium channel blockers (CCBs) alone or combined.

**If the initial treatment is not satisfactory, introduce another class of drugs (avoiding ARB - ACE I combinations) through titration process.

 

  • Standard doses of Antihypertensives NOT in the Essential Drug List

 

*Beta-blockers:

**Carvedilol: 12.5mg OD, increased after 2 days to 25mg OD. If need be, the dose may be increased to 50mg OD at an interval of at least 2 weeks.

**Atenolol: 50mg daily [some authorities consider higher doses unnecessary], otherwise max dose is 100mg daily.

**Bisoprolol: 5 - 20mg OD

**Labetalol: 100-400mg BD

**Propranolol: 80mg daily [max. 480mg daily].

**Metoprolol: 100-400mg daily orally. 1.V inj: 5-15mg depending on indications.

**Nebivolol: 5mg OD [max. 40mg]

**Sotalol: 120-240mg daily in a singly or divided dose before food.

 

*Vasodilator antihypertensives:

**Hydralazine: Slow IV: 5-10mg over 10. May be repeated after 20-30 minutes minutes.

 

*Centrally acting antihypertensives

**Methyldopa: Dose: Starting dose: 250mg BD or TID x 2/7 adjust until the desired effect is achieved.  Max. 3g daily. Children 10mg/kg daily in 2-4 doses [max. 65mg/kg or 3g daily whichever is less]. To minimize sedation, start dosage increases in the evening. When methyldopa tablets are added to a thiazide, the dosage of thiazide need not be changed. When methyldopa is given with other antihypertensives apart from thiazides for initial therapy the dosage of methyldopa should not exceed 500mg daily. After withdrawal of methyldopa, hypertension returns after 48 hours.

 

*Alpha-adrenoceptor blocking agents

**Doxazosin: 1 mg daily, increased after 1-2 wks to 2 mg OD, and thereafter to 4 mg OD, if necessary; max. 16mg daily.

**Indoramin: 25mg BD, increased by 25-50mg daily at intervals of 2 wks; max. daily dose 200 mg in 2-3 divided doses

**Prazosin: 500mcg 2-3 times daily for 3-7 days, the initial dose on retiring to bed at night [to avoid collapse, see cautions]; increased to 1mg 2-3 times daily for a further 3-7 days; further increased if necessary to max. 20mg daily in divided doses.

 

*Angiotensin-converting enzyme inhibitors (ACE inhibitors)

 

**Captopril: 12.5-50mg BD or 50mg OD. Children: 0.3mg/kg TID [interval of alteration of the dose is 2-4 wks].

**Enalapril: 5mg daily initially [max. 40mg daily]

**Lisinopril: 2.5mg daily. Maintenance dose: 10-20mg daily [max. 40mg daily].

**Perindopril (as an arginine salt): 5mg OD [the dose may be increased to 10mg after 1 month of treatment to improve blood pressure control or in case of concomitant stable coronary artery disease]

**Perindopril (as tert-butylamine salt): 2mg OD in the morning under close supervision.  Increased to maintenance dose of 4mg OD after 1-2 weeks only if BP acceptability is established [max 8mg OD].

**Ramipril: 1.25mg daily, increased at the interval of 1-2 wks [max. 10mg daily] after meals.

 

*Angiotensin Receptor Blockers (ARBs)

**Candesartan Cilexetil: 16 mg OD [max. daily dose 32mg].

**Irbesartan:150mg OD [up to daily dose 300mg].

**Losartan: 50mg OD (max. 100mg OD over several days).

**Olmesartan medoxomil: 10-40mg OD

**Telmisartan: 40mg OD (max. 100mg)

**Valsartan: 80mg OD.

 

*Calcium-channel blockers (CCBs)

**Amlodipine besylate: 5mg OD [max 10mg daily]

**Diltiazem:Angina pectoris and hypertension; 30-60mg TID or QID [max 480,g]. For long acting formulations: Hypertension and angina; 90-120mg BD [up to 360mg daily].

**Lacidipine: 4mg OD [max. 6mg].

**Nifedipine 10mg cap: indicated for angina, raynaud’s phenomenon and hypertension.Dose: 10mg TID with or after food. Usual maintenance: 5-20mg TID. For immediate effect in angina bite into capsule and retain liquid in mouth or swallow.

**Nifedine 20mg retard: Stable angina and hypertension: 10-20mg BD (max. 60mg daily).

**Nifedipine 30mg: Hypertension and angina, 30mg OD [max. 90mg OD].

**Verapamil: 240 - 480mg daily in 3-4 divided doses [orally].

 

*Treatment of hypertension in special conditions

**Heart failure: ACE inhibitors or ARBs  + beta blockers + diuretics  + spironolactone

**Chronic renal disease: ACE inhibitors or ARBs 

**Diabetes: ACE inhibitors or ARBs  + CCB + diuretic

**Pregnancy: Methyldopa, labetolol, nifedipine

**Coronary artery disease (CAD): ACE inhibitors  + beta blockers + diuretics + CCBs

**Recurrent stroke prevention: ACE inhibitors, diuretics

**Post myocardial infarction: ACE inhibitors or ARBs  + beta blockers

Drug Index 2.0 is here
Our new update features a more powerful search feature and easier login. Having any issues? Contact us today. Contact Us