Skip to main content

Hypertension-An Overview

INTRODUCTION:
Systemic arterial hypertension is one of the strongest known modifiable risk factors for ischaemic heart disease, stroke, renal failure and heart failure. It remains poorly treated. As an asymptomatic disorder, people are understandably reluctant to accept adverse drug effects in addition to the inconvenience of long-term treatment. In this regard, modern drugs represent an enormous improvement.

PATHOPHYSIOLOGY AND SITES OF DRUG ACTION
Hypertension is occasionally secondary to some distinct disease. However, most patients with persistent arterial hypertension have essential hypertension. Arterial blood pressure is determined by cardiac output, peripheral vascular resistance and large artery compliance. Peripheral vascular resistance is determined by the diameter of resistance vessels (small muscular arteries and arterioles) in the various tissues. One or more of a ā€˜mosaic’ of interconnected predisposing factors (including positive family history, obesity and physical inactivity among others) are commonly present in patients with essential hypertension, some of which are amenable to changes in diet and other habits. The importance of intrauterine factors (the ā€˜Barker hypothesis’) is supported by the finding that hypertension in adult life is strongly associated with low birth weight.
Cardiac output may be increased in children or young adults during the earliest stages of essential hypertension, but by the time hypertension is established in middle life the predominant haemodynamic abnormality is an elevated peripheral vascular resistance. With ageing, elastic fibres in the aorta and conduit arteries are replaced by less compliant collagen causing arterial stiffening and systolic hypertension, which is common in the elderly. The kidney plays a key role in the control of blood pressure and in the pathogenesis of hypertension. Excretion of salt and water controls intravascular volume. Secretion of renin influences vascular tone and electrolyte balance via activation of the renin–angiotensin–aldosterone system. Renal disease (vascular, parenchymal or obstructive) is a cause of arterial hypertension.
Conversely, severe hypertension causes glomerular sclerosis, manifested clinically by proteinuria and reduced glomerular filtration, leading to a vicious circle of worsening blood pressure and progressive renal impairment. Renal cross-transplantation experiments in several animal models of hypertension, as well as observations following therapeutic renal transplantation in humans, both point to the importance of the kidney in the pathogenesis of hypertension. The sympathetic nervous system is also important in the control of blood pressure, providing background α receptor mediated vasoconstrictor tone and β receptor-mediated cardiac stimulation. Sympathetic activity varies rapidly to adjust for changes in cardiovascular demand with alterations in posture and physical activity. It is also activated by emotional states such as anxiety, and this can result in ā€˜white-coat’ hypertension. A vasoconstrictor peptide, endothelin, released by the endothelium contributes to vasoconstrictor tone. Conversely, endothelium-derived nitric oxide provides background active vasodilator tone. Cardiovascular drugs work by augmenting or inhibiting these processes. The main such drugs for treating hypertension can usefully be grouped as:
  1. Angiotensin-converting enzyme inhibitors (ACEI) and angiotensin AT1 receptor antagonists (sartans);
  2. Beta-adrenoceptor antagonists
  3. Calcium channel antagonists
  4. Diuretics.
Each of these classes of drug reduces clinical end-points such as stroke, but in uncomplicated hypertension B drugs may be less effective than other classes. Other antihypertensive drugs useful in specific circumstances include α-adrenoceptor antagonists, aldosterone antagonists and centrally acting antihypertensive drugs.
GENERAL PRINCIPLES OF MANAGING ESSENTIAL HYPERTENSION

Consider blood pressure in the context of other risk factors: use cardiovascular risk to make decisions about whether to start drug treatment and what target to aim for:
  1.  Use non-drug measures (e.g. salt restriction) in addition to drugs. Explain goals of treatment and agree a plan the patient is comfortable to live with (concordance).
  2.  Review the possibility of co-existing disease (e.g. gout, angina) that would influence the choice of drug.
  3. Use a low dose and, except in emergency situations, titrate this upward gradually.
  4. Addition of a second drug is often needed. A drug of the other group is added, i.e. an A drug is added to patients started on a C or D drug, a C or D drug is added to a patient started on an A drug. A third or fourth drug may be needed. It is better to use such combinations than to use very high doses of single drugs: this seldom works and often causes adverse effects. 
  5.  Loss of control – if blood pressure control, having been well established, is lost, there are several possibilities to be considered:
  6. non-adherence;
  7. drug interaction – e.g. with non-steroidal anti-inflammatory drugs (NSAIDs)
  8. inter-current disease – e.g. renal impairment, atheromatous renal artery stenosis
Drugs used to treat Hypertension:


1. Angiotensin converting enzyme inhibitors.
Examples: Ramipril, Trandolapril, Enalapril, Lisinopril, Captopril
2. Angiotensin Receptor Blockers.
Examples: Losartan, Candesartan, Irbesartan, Valsartan
3. β-Adrenoreceptor  Antagonists.
Examples: Propranolol, Atenolol, Metoprolol, Esmlol, Sotalol, Labetalol, Oxprenolol

4, Calcium Channel Blockers.
Examples: Nefidipine, Amlodipine
5. Diuretics.
Examples: Thiazide Diuretics






Comments

Popular posts from this blog

Intellectual Property Rights and Portfolio Management in Pharmaceuticals

  Introduction The pharmaceutical industry depends heavily on intellectual property (IP) rights to stay innovative and competitive. Without these protections, companies risk losing the chance to profit from their discoveries. Managing a strong IP portfolio helps maximize research and development (R&D) investments, open doors to licensing deals, and keep drugs on the market longer. Still, this field faces many hurdles, including tough patent laws worldwide and changing regulations. At the same time, emerging opportunities can give companies a competitive edge if they master IP management. Understanding Intellectual Property Rights in Pharmaceuticals What Are Intellectual Property Rights? IP rights are legal tools that protect creations and ideas. In pharma, they help companies control and profit from their inventions for a certain time. Types of IP relevant to drugs include patents, trademarks, trade secrets, and data exclusivity. Each has a role in defending the company’s i...

Pharma Companies HR contact information

Dear viewers of my blog, I am happy to share the HR contact details of Pharmaceutical companies. Contact Details Of Pharma HRs : Zaydus cadila-Goa gajendravernekar@zayduscadila.com 09623458512/08326615143 Teva-Goa Maryann.Braganza@teva.co.in sanjay.pandit@teva.co.in 0832 6685538 Glenmark-Goa Vittal hebbalkar hr executivr - 9923476869 anupbannatti@glenmark-generics.com 09604151586 Watson-Goa Jyosna.bagule@watsonpharm.co.in runa.divkar@watsonpharm.co.in goa@watsonpharm.co.in 0832 6690666/777 Unichem Labs-Goa abhiram.panshikar@unichemlabs.com R&D  suraj.jadhav@unichemlabs.com vikas.parkar@unichemlabs.com Indico-Goa goahplc@Indoco.com varun.keny@indoco.com anand.ingole@Indoco.com 0832 6624109 Encube-Goa hr@encubeethicals.com nidhi.b@encubeethicals.com 8322392223 Torrent pharma-Ahmdabad mayurdesai@torrentpharma.com 9879603921/22/23/24 Emcure-pune RPKulkarni@emcure.co.in           Kishor.Mule@emcur...

An Overview of Brazil Patent litigation

  An Overview of Brazil Patent litigation Brazil plays a crucial role in Latin America's intellectual property landscape, particularly when it comes to patent litigation. The country's strong legal framework, governed by the Industrial Property Act, creates an environment where patents can be protected and enforced effectively. The Brazilian patent system serves as a vital mechanism for: Protecting innovative technologies Securing market advantages Fostering economic development Promoting technological advancement For businesses and inventors, understanding Brazil's patent litigation system is essential for success in this emerging market. The system's unique characteristics, including its bifurcated approach to handling infringement and invalidity cases, create distinct challenges and opportunities. Recent years have witnessed a surge in patent litigation cases, particularly in: Pharmaceutical sectors Technology industries Telecommunications Manufacturing This increa...