Methods of treating ischemic states

The present invention relates to novel methods of use for known pharmacological anti-allergenic agents including disodiumchromoglycate (DSCG) and related compounds thereof, including generally bis chromones, benzopyrans, oxamic acids and salts or esters of each, preferably lodoxamide, its THAM salt and ethyl ester. All are subsequently included in the term biologues. The methods are for the treatment of pathological cardiovascular ischemic states in animals, particularly humans. Additionally, novel compositions including the biologues of the present invention in combination with known vasodilators and feed stuffs are also disclosed.

DESCRIPTION 
BACKGROUND OF THE INVENTION 
The present invention relates to novel methods of using known 
pharmacological agents in man. The invention further relates to novel 
compositions employing these known pharmacological agents for the 
treatment of various conditions or diseases in animals. Particularly, the 
present invention relates to the use of these known pharmacological agents 
in the treatment of pathological cardiovascular ischemic states (VIS) 
in animals and man. 
The cardiovascular ischemic states whose treatment comprises the subject 
matter of the present invention are those states arising from 
physiological processes, particularly frankly pathological processes in 
which necrosis develops in smooth or striated muscles or skin. 
The cardiovascular ischemic state, which leads to the development of 
necrosis in the cardiac muscle, includes, for eample, angina, vasospastic 
angina, the sudden death syndrome, and the like. The ischemia resulting 
from these states is well known and is readily diagnosed by an attending 
physician or veterinarian. 
The cardiovascular ischemic states directly involving necrosis of smooth or 
striated muscle or skin include a wide variety of diseases and conditions. 
Further, certain cardiovascular ischemic states are a recognized untoward 
consequence of numerous other diseases and conditions. 
One principle class of cardiovascular ischemic states is a consequence of 
the various forms or types of vasospasms. Vasospasms refers to the 
abnormal spasm of the blood vessels, resulting in decrease in their 
caliber. Ischemic in this invention refers to the condition of having 
local and temporary deficiency of blood, due to the contraction of a blood 
vessel. 
Although it is known that the pharmacological agents now found to be useful 
in the treatment of pathological cardiovascular ischemic states were 
previously known for use as anti-allergenic agents, the mechanism for such 
previously known use is not appreciated. It is known that histamine plays 
a role in allergic reactions. Further this amine is a potent, easily 
released and functional endogenous compound in the body. For example, mast 
cells are the cells having granules in which histamine is highly 
concentrated. Histamine acts on two separate and distinct receptors, 
termed H.sub.1 and H.sub.2 receptors. Both H.sub.1 and H.sub.2 receptors 
mediate the vasodilator effects of histamine. Thus, the mast cells 
function in the healthy vertebrate by the release of histamine. However, 
the specific influences of the mast cell on ischemia is not well 
understood. For this reason, advantages of the present invention 
patentably extend methods of treating pathological cardiovascular ischemic 
states (VIS). See Goth et al., "Histamine", Medical Pharmacology, chap. 
15, pp. 117-188, 9th ed., C. V. Mosby Co., St. Louis, (1978). 
Vasospasm is a condition common in adults and typically results in a 
deficiency of blood to muscle or skin which is then at risk of developing 
necrosis. Vasospasms typically result in numerous systematic 
manifestations, characterized by ischemic disorders. Various types of 
vasospasms associated with ischemia are known. See for example, The Merck 
Manual, 13th edition, Merck, Sharp and Dohme Research Laboratories, 
Rahway, N.J. (1977). Among the types of vasospasms are those which produce 
angina pectoris attributed to myocardial ischemia. These vasospasms may 
progress to myocardial infarction, attributable to ischemic myocardial 
necrosis following an abrupt reduction in coronary flow to a segment of 
the myocardium. Vascular spasm may also contribute to occlusion of the 
abdominal aorta and its branches, such as splanchnic artery occlusion, 
renal artery occlusion, or occlusion at the bifurcation, and peripheral 
vascular disorders consequent to occlusive arterial diseases. Other 
notable disease states whose principle long term pathology arises from 
vasospasms as a constituent thereof include functional peripheral arterial 
disorders, such as Reynaud's phenomenon, acrocyanosis, and, rarely, 
erythromalalgia. For example, Reynaud's disease may be idiopathic or 
secondary to such conditions as occlusive arterial disease. Likewise, such 
pathology may result from connective tissue disorders; such as, 
progressive systemic sclerosis, neurogenic lesions, drug intoxication, 
dysproteinemias, myxedema, primary pulmonary hypertension, and trauma. 
Much less severe in its ultimate effect is the cardiovascular ischemic 
state resulting from acrocyanosis. 
Other disease conditions also induce pathological cardiovascular ischemic 
states (VIS) with resulting untoward effects on the affected animal. 
For example, arterial embolism or thrombosis may be due to a number of 
causes in an animal having a history of ischemia associated with 
vasospasm. Further, in many peripheral vascular diseases the vasospastic 
disorders induce pathological cardiovascular ischemic states with 
resulting pathological consequences. 
Other vasospastic diseases also have the effect of inducing a pathological 
cardiovascular ischemic state, for example, immersion foot, trench foot, 
herpes zoster, decubitous ulcers, and diabetic gangrene. 
Finally, while many cardiovascular ischemic states have been attributed in 
the past to excess vasospasm, measuring the extent of ischemia is a more 
recent development. Consequently, limiting the extent of the ischemia has 
likewise been difficult. For example, it has long been known in myocardial 
infarction that cardiac performance after recovery depends essentially on 
the mass of functioning muscle surviving the acute episode. Reinfarction 
or extension of infarct during hospitalization is common. The use of 
increased inspired O.sub.2 concentration is one avenue of treatment. 
Recent animal studies suggest that reduction of the O.sub.2 requirements 
of myocardium and an increase in coronary perfusion or reduction of after 
load with vasodilators reduce the area of ischemic infarction. The primary 
effects may be based on the lowering of peripheral resistance. These 
observations need further evaluation but in selected patients, especially 
those with elevated pressures, it appears to be appropriate in the acute 
stages of infarction to use vasodilators. These include such known agents 
as nitroglycerin, isosorbide dinitrate, trimethafan, or nitroprusside. 
Measuring the ischemic myocardium at risk of necrosis is discussed by 
DeBoer et al. in "Autoradiographic Method for Measuring the Ischemic 
Myocardium at Risk: Effects of Verapamil on Infarct size after 
Experimental Coronary Artery Occlusion", Proc. Natl. Acad. Sci. U.S.A., 
vol. 77, no. 10, pp. 6119-6123, October, 1980, Medical Sciences. Such 
measurement in the investigation of pharmacological agents is advantageous 
since myocardial infarct size appears to be a function of ischemia 
myocardium at risk of developing necrosis. Numerous methods have been 
reported for assessing the effectiveness of pharmacological agents 
including by indirect methods. For example, one such report indicates 
determination of epicardial enosis. See Kloner, R. A. et al., Circulation, 
vol. 58, pp. 220-226 (1978). Another indirect method is described as 
"Factors Influencing Infarct Size Following Experimental Coronary Artery 
Occlusions" by Maroko, P. R. et al., Circulation, vol. 43, pp. 67-82 
(January, 1971). Direct methods include postmortem injection of dyes 
described by Reimer, K. A. et al. Lab. Invest., vol. 40, pp. 633-644 
(1979) or angiographic contrast agents described by Jugdutt, B. I. et al., 
Circulation, vol. 60, pp. 1141-1150 (1979), Jugdutt, B. I. et al., 
Circulation, vol. 59, pp. 734-743 (1979), Hoffman, M. et al. Circulation, 
vol. 60, II-215A (

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The advantageous effects of anti-VIS biologues in accordance with the 
present invention are demonstrated by the experimental results, reported 
hereinafter, which are illustrative (but not limiting) as to the operation 
of the novel methods described above. 
EXAMPLE 1 
The reduction of myocardial infarct size as measured by the effects on 
infarct size after experimental coronary artery occlusion of lodoxamide, 
N,N'-(2-chloro-5-cyano-n-phenylene)dioxamic acid, (as its 
bis-tris(hydroxymethyl)aminomethane salt). 
Following the procedure of DeBoer, W. E. et al., Proc. Natl. Acad. Sci. 
U.S.A., vol. 77, no. 10, pp. (6119-6123 (October, 1980) Medical Sciences, 
the anti-VIS activity of lodoxamide is assessed. The following 
experiment is undertaken. 
Twenty-two barbiturate anesthetized dogs are treated to receive high left 
anterior descending coronary artery occlusions. Ischemic bed size or area 
at risk of developing necrosis (AR-R) is determined before treatment by 
injection of 99 m Tc labeled albumin microspheres with post-mortem 
autoradiography. The ischemic zone appears as a cold spot image. A second 
area at risk is determined at the time of sacrifice (AR-D) by use of an in 
vivo left atrial injection of thioflavin S (a fluorescent dye which stains 
myocardium receiving flow yellow-green, but does not stain ischemic 
tissue). Infarct size (IS) is determined six hours after coronary 
occlusion by triphenyltetrazolium staining of 5 mm transverse slices of 
the left ventricle. Thirty minutes after left anterior descending coronary 
occlusion, animals are randomized to controls (12 dogs receiving 0.9 
percent saline I.V.) or lodoxamide, 
N,N'-(2-chloro-5-cyano-n-phenylene)dioxamic acid, (as its 
bis-tris-(hydroxymethyl)aminomethane salt) therapy (10 dogs receiving 20 
mg per kg per hour by continuous I.V. drip). AR-R, AR-D, and IS are 
expressed as percentage of the left ventricle before occlusion. Infarct 
size is also expressed as a percentage of the area at risk. The results 
are shown in the table below. 
TABLE I 
______________________________________ 
Lodoxamide 
Controls THAM Salt P 
______________________________________ 
AR-R 28.7 + 2.6 25.3 + 3.7 NS 
AR-D 28.9 + 2.5 25.2 + 3.1 NS 
IS 30.0 + 2.7 13.8 + 3.2 .002 
IS/AR-R 104.5 + 3.8 54.5 + 11.0 
.001 
IS/AR-D 103.8 + 3.4 54.8 + 8.2 .001 
______________________________________ 
The results of Table I indicate the oxamate, lodoxamide induces a 
significant protective action on ischemic myocardium by showing a 
significant reduction in infarct size. 
A further experiment indicates the prevention of necrosis by the oxamate, 
lodoxamide in a prophylactic manner in a manner similar to Example I. 
Example II 
Fourteen dogs are treated to receive occlusion of the proximal left 
circumflex coronary artery. Ischemic bed size or area at risk of 
developing necrosis (AR-R) is determined before treatment by injection of 
99 m Tc labeled albumin microspheres with postmortem autoradiography. A 
second area at risk is determined at the time of sacrifice (AR-D) by use 
of an in vivo left atrial injection of thioflavin S (a fluorescent dye 
which stains myocardium receiving flow yellow-green, but does not stain 
ischemic tissue) in a manner similar to Example 1. The animals are 
randomized to controls (9 dogs) or lodoxamide therapy (8 dogs receiving 20 
mg/kg/hour times two infused I.V. during the period starting 30 minutes 
prior to and throughout 90 minutes of complete occlusion, followed by 
reperfusion). Infarct size (IS) is determined 24 hours after the 90 minute 
occlusion-reperfusion. The results are shown below in a manner similar to 
that described for Example I. In other words, the following Table II shows 
infarct size determined as a percent of the area at risk or as a percent 
of the total left ventricle. 
TABLE II 
______________________________________ 
Lodoxamide 
Control THAM Salt P 
______________________________________ 
AR-R 45.3 + 2.8 22.8 + 2.8 0.001 
AR-D 42.8 + 1.7 43.1 + 3.6 NS 
IS 19.5 + 1.5 9.7 + 1.0 0.001 
______________________________________ 
The results in Table II show the oxamide therapy occasions a decrease in 
infarct size.