MEDICINAL CHEMISTRY

congenital heart disease, can cause chronic and severe pulmonary HTN while RV-
failure and mitral stenosis can cause immediate pulmonary HTN. Approximately
2,00,000 death/annum in the world occurs from acute pulmonary embolism (a
common cause of sudden onset of pulmonary HTN).
b. Portal hypertension: If the portal venous flow becomes obstructed, there is rise in BP
because a collateral circulation develops; diverting the portal flow into systemic
venous. It is reported that main cause of increased portal pressure is increased
vascular resistance related to hepatic fibrosis, scaring regenerative nodules and
increased blood flow. The causes of portal hypertension are categorized as prehepatic,
intra-hepatic and post-hepatic which can be diagnosed by endoscopy and ultrasound
(Lake, 2000).
c. Childhood hypertension: It is based on the normal distribution of systolic and
diastolic BP in the general population for the children of comparable age, weight and
height:
d. Renal parenchymal hypertension: It is associated with renal parenchymal disease
and the most common form of secondary hypertension; 5% of all hypertensive
patients have underlying renal disease. Among them 80% and 90 % are with pre-endstage
renal disease (pre-ESRD) and end-stage renal disease (ESRD) respectively.
e. Reno-vascular hypertension: Its presence is confirmed only by showing that HBP is
improved or cured after correction of occlusion. It is resulted from the activation of
renin-angiotensin-aldosterone axis mediated by ischemia. In 95% cases, the common
cause for this type of HTN is atherosclerosis and fibromuscualr dyspalsmia.
f. Drug induced hypertension: HTN related to medication is a disorder characterized by
HBP caused by a response to using, or stopping the use of a chemical substance, drug
or medication. It is a form of secondary hypertension caused by a response to
medication. Examples include using substances such as alcohol or medications such
as corticosteroids, cyclosporine, estrogen (including birth control pills), nasal
decongestants, corticotropin or other hormones, sympathomimetic medications,
which is found in many over-the-counter medications such as cough/cold medicines
and medications for asthma or particularly when the cough/cold medicine is taken by
a person who also takes tranylcypromine or tricyclic antidepressants.It can also be a
result of stopping the use of antihypertensive medication such as clonidine. This is
called rebound hypertension.
g. Pseudo-hypertension: It may occur in elderly patients with very stiff arteries. In such
patients, sphygmomanometry may detect spurious blood pressure elevations because
the cuff cannot completely occlude the sclerotic brachial artery (Osler's sign). It may
be diagnosed when elderly patients treated for hypertension develop excessive fatigue
or severe orthostasis.
Recently, scientific committee on high blood pressure has specified different levels of
blood pressure and limited the range of high blood pressure in only 3 stages: