# Patent

## Title
Piperidine compounds and their preparation and use

## Abstract

This is a continuation of application Ser. No. 07/561,743 filed Aug. 2, 1990, now abandoned.

## Background
The invention relates to compositions comprising combinations of a PAF antagonist and a LTD.sub.4 antagonist which combinations synergistically provide protection against allergic reactions such as antigen-induced death in mammals.

In another aspect, the invention relates to the use of the referred to combinations in the treatment of allergic reactions.

The invention relates compositions comprising the synergistic combination of platelet activating factor (PAF) antagonists with leukotriene D.sub.4 (LTD.sub.4) antagonists and the use thereof to treat allergic reactions.

The mechanism of pathogenesis associated with allergic reactions involves an antigen-induced release of a variety of allergic mediators from mast cells, basophils, and possibly macrophages. These mediators include histamine, leukotrienes and PAF all of which posses a broad spectrum of potent biological activities. [Schleimer, R. P., Am. Rev. Respir. Dis., 133, 614-617 (1986)]. [Barnes, P. J., J. Allergy Clin. Immunol., 81,152-160 (1988)]. Assessment of the precise contribution of each individual allergic mediator to the pathology of allergic reactions is unknown.

For example, allergic asthma involves the antigen-induced release of allergic mediators from mast cell which subsequently cause bronchoconstriction, mucus secretion, and changes in capillary permeability which, in combination with the production of chemotactic agents, leads to the influx into the lung of inflammatory cells. The mediators rapidly induce a narrowing and occluding of the bronchial lumen of the airways and, over time, the development of a chronic inflammatory condition in the lungs. Inflammation of the airways may be essential to the establishment of bronchial hyperresponsiveness which is the characteristic abnormality of asthma. [Chung, K. F., Thorax, 41, 657-662 (1986)]. It has been difficult to identify the predominant mediator(s) of allergic asthma, but in recent years a number of lines of evidence strengthen the concept that the bronchoactive peptidoleukotrienes (LTC.sub.4, LTD.sub.4, and LTE.sub.4) and PAF may be important in this disease process. LTD.sub.4 and PAF have been identified in body fluids during an episode of asthma. They are both potent mediators of inflammation, and can reproduce some of the pathophysiological features of the disease when administered to animals and man. [O'Donnell, M. in Therapeutic Approaches to Inflammatory Diseases, A. J. Lewis, N. S. Doherty and N. R. Ackerman, eds., Elsevier Science Publishing Co., New York, 169-193 (1989)].

Compounds which prevent the effects of the mediators are thus of interest in treating allergic reactions. However, since allergic reactions are complex processes that are probably not attributable to a single causative factor, a potent, specific, agent by itself may not be particularly effective in preventing allergic reactions.

Surprisingly, it has now been found that protection against allergic reactions such as antigen-induced death in mammals can be achieved by administering to such mammals an effective amount of a composition comprising a synergistic combination of a PAF antagonist and a LTD.sub.4 antagonist.

In accordance with the invention, there can be used as the PAF antagonist component of a composition of the invention a known compound selected from the group consisting of: [1,4]diazepin-2-yl]-2-propynyl}phenanthridin-6(5H)-one; ienamide; butyl]thiazolium iodide; [4,5]thieno 3,2-f][1,2,4]triazolo[4,3-a][1,4]diazepin-8-yl]carbonyl}morpho line; ta[4,5]thieno[3,2-f][1,2,4]triazolo[4,3-a][1,4]diazepine-8-carboxamide; yclopenta [4,5]thieno[3,2-f][1,2,4]triazolo[4,3-a][1,4]diazepine; [3,2-f] [1,2,4]triazolo[4,3-a][1,4]diazepine; ieno[3,2-f] [1,2,4]triazolo[4,3-a][1,4]diazepine; uinoline; oxyphenyl)tetrahydrofuran; yl, pyridinium chloride; oxamide; and -ylidene)piperidine.

Preferred PAF antagonists comprise the following compounds: [1,4]diazepin-2-yl]-2-propynyl}phenanthridin-6(5H)-one; ienamide; ] thiazolium iodide; and oxyphenyl)tetrahydrofuran.

Most preferred PAF antagonists are: [1,4]diazepin-2-yl]-2-propynyl}phenanthridin-6(5H)-one; and ienamide.

Also, in accordance with the invention, there can be used as the LTD.sub.4 antagonist component of a composition a known compound selected from the group consisting of: obutanoic acid; dro-2H-1-benzopyran-2-carboxylic acid; acid, mono N,N-dimethylamide, sodium salt; 1-methyl-1H-indol-5-yl]-carbamic acid, cyclopentyl ester; 4-oxobutanoic acid; H-tetrazole; c acid; butoxy]phenyl]ethanone; phenyl}-1H-tetrazole yl]-1H-tetrazole-5-carboxamide, sodium salt; n; butoxy)benzamide; 4-oxo-8-propyl-2H-1-benzopyran-2-propanoic acid; 2-yl]thio] acetic acid; do[1,2-a]pyrimidin-4-one; idin-9(1H)-one; and

Preferred LTD.sub.4 antagonists comprise the following compounds: obutanoic acid; dro-2H-1-benzopyran-2-carboxylic acid; and acid, mono N,N-dimethylamide, sodium salt.

A most preferred LTD.sub.4 antagonist is: obutanoic acid.

The synergistic compositions and methods of the invention due to their antiallergic activity, can be utilized for the treatment of allergic disorders such as seasonal rhinitis, perennial vasomotor rhinitis, acute urticaria, chronic urticaria, atopic dermatitis, contact dermatitis, pruritis, angioedema, conjunctivitis, chronic bronchitis, systemic anaphylaxis, serum sickness, bronchial asthma, food allergies, and related inflammatory diseases including inflammatory bowel disease, and psoriasis.

The anti-allergic effect of the compositions of the invention comprising combinations of PAF antagonists and LTD.sub.4 antagonists may be demonstrated utilizing procedures described hereinafter.

Male (Hartley) guinea pigs (200-300 g) are sensitized with an intraperitoneal injection of ovalbumin (10 mg) in 1 ml of 0.9% w/v NaCl solution (saline) on days 1 and 3. The animals are used for the test on days 20-30 following the ovalbumin injections.

The sensitized guinea pigs are anesthetized with an intraperitoneal injection of urethane (2 g/kg), and polyethylene cannulae are introduced into both jugular veins and the right carotid artery. The arterial catheter is connected to a pressure transducer (Model 50, Statham Instruments, Inc., CA) for measurement to systemic blood pressure. The venous catheters are used for injection and infusion of the test composition.

The trachea is cannulated through an anterior cervical incision and positive pressure ventilation is applied with a Harvard pump set at a stroke volume of 4.5 ml and a rate of 40 breaths per minute. The respiratory muscles are paralyzed by periodic injections of succinylcholine chloride (1.2 mg/kg) given intravenously.

To measure transpulmonary pressure, a 12-gauge hypodermic needle attached via a short length of Tygon tubing to one side of a Statham differential pressure transducer (Model P131TC) is introduced through the fifth or sixth intercostal space into the intrapleural space near the sternum, leaving a pneumothorax. The other side of this transducer is connected to the side-arm of the tracheal cannula by a second Tygon tube of identical length and bore as the first. Airflow is measured with a Fleisch pneumotachograph head (type #0000, Instrumentation Associated, Inc., New York, NY) connected to a tracheal cannula and a second Statham differential pressure transducer (Model PM15). Electrical integration of the flow signal provides a recording of tidal volume.

Pulmonary resistance and dynamic lung compliance are calculated manually from the transpulmonary pressure, airflow, and volume signals as described by Amdur and Mead and the results are used to calibrate an on-line analog pulmonary computer (Buxco Electronics, Inc., Sharon, CO). [Am. J. Physiol., 192,364-368 (1958)]. Blood pressure is recorded with a cannula inserted into the carotid artery. Heart rate is calculated by an on-line analog cardiovascular computer (Buxco Electronics, Inc., Sharon, CO). All six parameters (airflow, transpulmonary pressure, tidal volume, resistance, compliance and blood pressure) are recorded simultaneously on a polygraph recorder (Model 7758A, Hewlett Packard, Paramus, NJ), and these parameters, plus heart rate and respiratory rate, are printed out on an electronic data terminal (Texas Instruments, Houston, TX). After completion of surgery, a period of no less than 5 minutes is allowed for cardiopulmonary functions to stabilize. During this period, control values are recorded continuously.

Following surgical preparation, the animals are pretreated with intravenous indomethacin (10 mg/kg) 22 minutes before ovalbumin challenge presumably to shunt arachidonic acid from the cyclooxygenase pathway into the lipoxygenase pathway for the formation of leukotrienes, and to eliminate the modulating effects of prostaglandins. Spontaneous breathing is arrested with succinylcholine (1.2 mg/kg, i.v.) 7 minutes before antigen challenge. Treatment with succinylcholine results in a constant baseline ventilatory pressure of 6-8 cm H.sub.2 O. The bronchoconstrictor effects of histamine are abolished with pyrilamine (2.0 mg/kg, i.v.), administered 6 minutes before antigen challenge. To potentiate the bronchoconstrictor effect of antigen, propranolol (0.1 mg/kg, i.v.) is administered before antigen challenge. [Anderson, W. H., et al., Br. J. Pharmacol., 78,67-74 (1983)].

Various antagonists or control vehicle are administered intravenously through a cannula in the jugular vein 5 minutes before the animals are challenged with a maximum constrictory dose of ovalbumin (1 mg/kg) given intravenously.

The percent change in pulmonary resistance, dynamic lung compliance, and the systemic blood pressure and survival time are monitored for 120 minutes.

When the aforementioned model of anaphylaxis procedure was utilized to test various combinations of the invention, animals administered vehicle alone and challenged with antigen exhibited bronchoconstriction (approximately 550% increase in pulmonary resistance and 80% decrease in dynamic lung compliance), hypotension (55 mmHg decrease), and 83% mortality within 120 minutes. Table I contains the results obtained in this model with various combinations of the invention. ______________________________________ PROTECTION OF ANAPHYLACTIC DEATH IN SENSITIZED GUINEA PIG BY THE SYNERGISTIC COMPOSITIONS OF THE INVENTION COM-    DOSE                    % SURVIVAL POUNDS  mg/kg. i.v. COMPOUND     at 120 min. ______________________________________ ALONE* Control Vehicle                         17 A       (1 mg/kg)  PAF antagonist 0 B       (1 mg/kg)  LTD.sub.4 antagonist 0 C       (1 mg/kg)  LTD.sub.4 antagonist 50 D       (10 mg/kg) LTD.sub.4 antagonist 0 E       (1 mg/kg)  PAF antagonist 33 F       (1 mg/kg)  PAF antagonist 0 G       (1 mg/kg)  PAF antagonist 50 COMBINATIONS OF THE INVENTION* A + B                       100 A + C                       100 A + D                       100 B + E                       100 B + F                       100 B + G                       100 C + G                       100 ______________________________________ *COMPOUNDS A 5{3-[4-(2-chlorophenyl)-9-methyl-6H-thieno[3,2-f]1,2,4]triazolo[4,3-a][1, ]diazepin-2-yl]-2-propynyl}phenanthridin-6(5H)-one. B (E)4-[3-[2-(4-cyclobutyl-2-thiazolyl)ethenyl]phenylamino]-2,2-diethyl-4-o obutanoic acid. C 5(3-(2-(7-chloroquinolin-2-yl)ethenyl)phenyl)-4,6-dithianonane dicarboxylic acid, mono N,Ndimethylamide, sodium salt. D rac6-acetyl-7-[[5-(4-acetyl-3-hydroxy-2-propylphenoxy)pentyl]oxy]-3,4-dih dro-2H-1-benzopyran-2-carboxylic acid. E (R)(2E,4E)-5-(4-methoxyphenyl)-N-[1-methyl-4-(3-pyridinyl)butyl]-2,4-deca ienamide. F 3[4-[(R)-2-[(methoxycarbonyl)oxy]-3-[(octadecylcarbamoyl)oxy]propoxy]buty ]thiazolium iodide. G (2S,5S)2-[(3-methylsulfonyl-5-methoxy-4-propyloxy)phenyl]-5-(3,4,5-trimet oxyphenyl)tetrahydrofuran.

The ability of the LTD.sub.4 antagonist, compound B- (E)-4-[3-[2-(4-cyclobutyl-2-thiazolyl)ethenyl]phenylamino]-2,2-diethyl-4-o xobutanoic acid, and the PAF antagonist, compound A- 5-{3-[4-(2-chlorophenyl)-9-methyl-6H-thieno[3,2-f][1,2,4]triazolo[4,3-a][1 ,4]diazepin-2-yl]-2-propynyl}phenanthridin6(5H)-one, to block antigen-induced bronchospasm, hypotension and death was evaluated at doses (1.0 mg/kg, i.v., 5 minute pretreatment) previously shown to completely inhibit bronchoconstriction induced by exogenous LTD.sub.4 or PAF, respectively. Animals treated with compound B- (E)-4-[3-[2-(4-cyclobutyl-2-thiazolyl)ethenyl]phenylamino]-2,2-diethyl-4-o xobutanoic acid or compound A- 5-{3-[4-(2-chlorophenyl)-9-methyl-6H-thieno [3,2-f] [1,2,4] triazolo [4,3-a] [1,4] diazepin-2-yl]-2-propynyl}phenanthridin-6(5H)-one alone had a 0% survival rate at 120 minutes, whereas when the combination was given, there was 100% survival at 120 minutes.

The ability of the LTD.sub.4 antagonist, compound C- 5-(3-(2-(7-chloroquinolin-2-yl)ethenyl)phenyl)-4,6-dithianonanedicarboxyli c acid, mono N,N-dimethylamide, sodium salt, and the PAF antagonist, compound A- 5-{3-[4-(2-chlorophenyl)-9-methyl-6H-thieno [3,2-f] [1,2,4] triazolo [4,3-a] [1,4]diazepin-2-yl]-2-propynyl}phenanthridin-6(5H)-one, to block antigen-induced bronchospasm, hypotension and death was evaluated at doses (1.0 mg/kg, i.v., 5 minute pretreatment) previously shown to completely inhibit bronchoconstriction induced by exogenous LTD.sub.4 or PAF, respectively. Animals treated with compound C- 5-(3-(2-(7-chloroquinolin-2-yl)ethenyl) phenyl)-4, 6-dithianonanedicarboxylic acid, mono N,N-dimethylamide, sodium salt alone had a 50% survival rate at 120 minutes and those treated with compound A- 5-{3-[4-(2-chlorophenyl)-9-methyl-6H-thieno [3,2-f] [1,2,4] triazolo [4,3-a] [1,4] diazepin-2-yl]-2-propynyl}phenanthridin-6(5H)-one alone had a 0% survival rate at 120 minutes. However, when the combination was given, there was 100% survival at 120 minutes.

The ability of the LTD.sub.4 antagonist, compound D- rac-6-acetyl-7-[[5-(4-acetyl-3-hydroxy-2-propylphenoxy)pentyl]oxy]-3,4-dih ydro-2H-1-benzopyran-2-carboxylic acid, and the PAF antagonist, compound A- 5-{3-[4-(2-chlorophenyl)-9-methyl-6H-thieno [3,2-f] [1,2,4] triazolo[4,3-a][1,4]diazepin-2-yl]-2-propynyl} phenanthridin-6(5H)-one, to block antigen-induced bronchospasm, hypotension and death was evaluated at doses (10 mg/kg and 1.0 mg/kg, i.v., 5 minute pretreatment, respectively) previously shown to completely inhibit bronchoconstriction induced by exogenous LTD.sub.4 or PAF, respectively. Animals treated with compound D- rac-6-acetyl-7-[[5-(4-acetyl-3-hydroxy-2-propylphenoxy) pentyl[oxy]-3,4-dihydro-2H-1-benzopyran-2-carboxylic acid or compound A- 5-{3-[4-(2-chlorophenyl)-9-methyl-6H-thieno[3,2-f][1,2,4]triazolo[4,3-a][1 ,4]diazepin-2-yl]-2 -propynyl}phenanthridin-6(5H)-one alone had a 0% survival rate at 120 minutes, whereas when the combination was given, there was 100% survival at 120 minutes.

The ability of the LTD.sub.4 antagonist, compound B- (E)-4-[3-[2-(4-cyclobutyl-2-thiazolyl)ethenyl]phenylamino]-2,2-diethyl-4-o xobutanoic acid, and the PAF antagonist, compound E- (R)-(2E,4E)-5-(4-methoxyphenyl)-N-[1-methyl-4-(3-pyridinyl)butyl]-2,4-deca dienamide, to block antigen-induced bronchospasm, hypotension and death was evaluated at doses (1.0 mg/kg, i.v., 5 minute pretreatment) previously shown to completely inhibit bronchoconstriction induced by exogenous LTD.sub.4 or PAF, respectively. Animals treated with compound B- (E)-4-[3-[2-(4-cyclobutyl-2-thiazolyl) ethenyl]phenylamino]-2,2-diethyl-4-oxobutanoic acid alone had a 0% survival rate at 120 minutes and those treated with compound E- (R)-(2E,4E)-5-(4-methoxyphenyl)-N-[1-methyl-4-(3pyridinyl)butyl]-2,4-decad ienamide alone had a 33% survival rate at 120 minutes. However, when the combination was given, there was 100% survival at 120 minutes.

The ability of the LTD.sub.4 antagonist, compound B- (E)-4-[3-[2-(4-cyclobutyl-2-thiazolyl)ethenyl]phenylamino]-2,2-diethyl-4-o xobutanoic acid, and the PAF antagonist, compund F- 3-[4-[(R)-2-[(methoxycarbonyl)oxy]-3-[(octadecylcarbamoyl) oxy] propoxy] butyl] thiazolium iodide, to block antigen-induced bronchospasm, hypotension and death was evaluated at doses (1.0 mg/kg, i.v., 5 minute pretreatment) previously shown to completely inhibit bronchoconstriction induced by exogenous LTD.sub.4 or PAF, respectively. Animals treated with compound B- (E)-4-[3-[2-(4-cyclobutyl-2-thiazolyl)ethenyl] phenylamino]-2,2-diethyl-4-oxobutanoic acid alone had a 0% survival rate at 120 minutes and those treated with compound F- 3-[4-[(R)-2-[(methoxycarbonyl) oxy]-3-[(octadecylcarbamoyl)oxy]propoxy]butyl] thiazolium iodide alone had a 0% survival rate at 120 minutes. However, when the combination was given, there was 100% survival at 120 minutes.

The ability of the LTD.sub.4 antagonist, compound B- (E)-4-[3-[2-(4-cyclobutyl-2-thiazolyl)ethenyl]phenylamino]-2,2-diethyl-4-o xobutanoic acid, and the PAF antagonist, compound G- (2S,5S)-2-[(3-methylsulfonyl-5-methoxy-4-propyloxy)phenyl]-5-(3,4,5-trimet hoxyphenyl)tetrahydrofuran to block antigen-induced bronchospasm, hypotension and death was evaluated at doses (1.0 mg/kg, i.v., 5 minute pretreatment) previously shown to completely inhibit bronchoconstriction induced by exogenous LTD.sub.4 or PAF, respectively. Animals treated with compound B- (E)-4-[3-[2-(4-cyclobutyl-2-thiazolyl)ethenyl] phenylamino]-2,2-diethyl-4-oxobutanoic acid alone had a 0% survival rate at 120 minutes and those treated with compound G- (2S,5S)-2-[(3-methylsulfonyl-5-methoxy-4-propyloxy)phenyl]-5-(3,4,5-trimet hoxyphenyl)tetrahydrofuran alone had a 50% survival rate at 120 minutes. However, when the combination was given, there was 100% survival at 120 minutes.

The ability of the LTD.sub.4 antagonist, compound C- 5-(3-(2-(7-chloroquinolin-2-yl)ethenyl)phenyl)-4,6-dithianonanedicarboxyli c acid, mono N,N-dimethylamide, sodium salt, and the PAF antagonist, compound G-(2S,5S)-2-[(3-methylsulfonyl-5-methoxy-4-propyloxy) phenyl]-5-(3,4,5-trimethoxyphenyl)tetrahydrofuran, to block antigen-induced bronchospasm, hypotension and death was evaluated at doses (1.0 mg/kg, i.v., 5 minute pretreatment) previously shown to completely inhibit bronchoconstriction induced by exogenous LTD.sub.4 or PAF, respectively. Animals treated with compound C-5-(3-(2-(7-chloroquinolin-2-yl)ethenyl)phenyl)-4,6-dithianonanedicarboxy lic acid mono N,N-dimethylamide, sodium salt alone had a 50% survival rate at 120  minutes and those treated with compound G- (2S,5S)-2-[(3-methylsulfonyl-5-methoxy-4-propyloxy)phenyl]-5-(3,4,5-trimet hoxyphenyl)tetrahydrofuran alone had a 50% survival rate at 120 minutes. However, when the combination was given, there was 100% survival at 120 minutes.

The compositions of the invention may be administered by any of the modes by which the individual components may be administered, for example, orally, intravenously or the like. The dosage regiment may be regulated according to the potency of individual compounds employed, the mode of administration, and the needs of the host mammal depending on factors such as the degree and the severity of the disease state and age and general condition of the host mammal being treated.

The compositions of the invention can be administered in unit dosage forms such as tablets, capsules, pills, powders, granules, sterile parenteral solutions or suspensions, suppositories, transdermal compositions, aerosols and the like. Such dosage forms are prepared according to standard techniques in the art.

The dosages may be varied depending upon the requirements of the host, the severity of the condition being treated and the particular compound being employed in the composition. Determination of the proper dosage for a particular administration is within the skill of the art. Generally, treatment is initiated at lower dosages and increased as needed by small increments until the optimum effect is reached. Exemplary dosages are in the range of from 0.1 to 4.0 gm per day of a combination of the invention. Exemplary dosages of the PAF antagonist can be in the range of 0.01 to 2.0 gms per day. Exemplary dosages of the LTD.sub.4 antagonist can be in the range of 0.1 to 2.0 gms per day. Generally, the PAF antagonist is present in a ratio of from about 0.01 to about 50 parts to one part of the LTD.sub.4 antagonist, preferably in a ratio of from 0.1 to about 10 parts to one part of the LTD.sub.4 antagonist. For convenience, the total daily dosage may be administered in divided doses. TABLET FORMULATION Item    Ingredients       mg/Tablet ______________________________________ 1       Compound A.sup.(1) 0.1    mg  250  mg 2       Compound B.sup.(1) 1.0    mg  250  mg 3       Croscarmellose Sodium* 6.4    mg  30   mg 4       Lactose           100    mg  255  mg 5       Avicel PH 101     20     mg  60   mg 6       Methocel E15**    1.5    mg  9    mg 7       Magnesium Stearate 1.0    mg  6    mg 130    mg  860  mg ______________________________________ *Other disintegrants, such as starch derivatives, CrossPovidone, Amberlite, or similar in action may be used alone or in combination to obtain desired disintegration characteristics. **Binders, such as pregelatinized starch or polyvinylpyrrolidone, etc., may be used to obtain a desired binding. Wetting agents, such as Tweens, spans, or sodium lauryl sulfate may be added to obtain desired disintegration and dissolution characteristics. .sup.(1) As used hereinafter Compound A is 5{3-[4-(2-chlorophenyl)-9-methyl-6H-thieno[3,2-f][1,2,4]triazolo[4,3-a][1 4]diazepin-2-yl]-2-propynyl} phenanthridin-6(5H)-one, and Compound B is (E)4-[3-[2-(4-cyclobutyl-2-thiazolyl)ethenyl]phenyl amino]-2,2diethyl-4-oxobutanoic acid. CAPSULE FORMULATION Item    Ingredients      mg/Capsule ______________________________________ 1       Compound A       0.1    mg  250  mg 2       Compound B       1.0    mg  250  mg 3       Pregelatinized Starch 5      mg  20   mg 4       Modified Starch  5      mg  20   mg 5       Talc             4.4    mg  20   mg 6       Lactose          84     mg  88   mg 7       Magnesium Stearate 0.5    mg  2    mg 100    mg  650  mg ______________________________________ SOFT GELATIN CAPSULE FORMULATION Item    Ingredients       mg/mL ______________________________________ 1       Compound A        0.1    mg  250  mg 2       Compound B        1.0    mg  250  mg 3       Ethoxylated Fatty Acids 50     mg  250  mg 4       PEG-400           100    mg  100  mg 5       Vegetable Oils q.s. to 1.0    mg  1.0  mg ______________________________________ ORAL SOLUTION FORMULATION Item  Ingredients       mg/5 mL ______________________________________ 1     Compound A        0.1    mg   100  mg 2     Compound B        1.0    mg   100  mg 3     Alcohol, Anhydrous 10     mg   500  mg 4     PVP K-30          10     mg   500  mg 5     Aq. Sod. Hydroxide Solution 1.0    mg   100  mg 6     Sucrose                  q.s.      q.s. 7     Flavoring Agent          q.s.      q.s. 8     PEG-400 q.s. to   5.0    mL   5.0  mL ______________________________________ PARENTERAL FORMULATION (for I.V. or IM use) Item  Ingredients      mg/mL ______________________________________ 1     Compound A       0.1     mg   10   mg 2     Compound B       1.0     mg   10   mg 3     Benzyl Alcohol   10      mg   20   mg 4     Propylene Glycol* 0.4     mL   0.5  mL 5     Emulphor EL620** 10      mg   50   mg 6     Lactic Acid      0.01    mL   0.05 mL 7     Sod. Hydroxide pH to     6-7       6-7 8     Water for Injection q.s. to 1.0     mL   1.0  mL ______________________________________ *Solvents or solubilizers, such as polyethylene glycols, alcohol, glycerine, Povidone, lecithin, sorbitan monooleate, or trioleate. Polysorbate 80 or 20 may be used in combination or alone to achieve the adequate solubility and stabilization. **Powder for reconstitution may be formulated for appropriate solubilization or stabilization. INHALATION AEROSOL FORMULATION (Suspension) Item    Ingredients       % w/w ______________________________________ 1       Compound A, Micronized 0.01   mg   0.5 2       Compound B, Micronized 0.1    mg   0.5 3       Sorbitan Trioleate 0.5    mg   0.5 4       Freon 11          19.39  mL   18.5 5       Freon 12          80     mg   80.0 TOTAL     100% ______________________________________ valve, and crimp to seal container. INHALATION AEROSOL FORMULATION (Solution) Item      Ingredients    % w/w ______________________________________ 1         Compound A     0.01     0.5 2         Compound B     0.1      0.5 3         Ethyl Alcohol  10       30.0 4         Ascorbic Acid  0.5      0.5 5         Freon 114      20.0     -- 6         Freon 12       68.5     68.5 TOTAL    100% ______________________________________ and crimp to seal container.

## Claims

1. A pharmaceutical composition useful in the treatment of allergic disorders comprising an effective amount of a combination of a PAF antagonist and a LTD.sub.4 antagonist, wherein the amount of the PAF antagonist is in the range of from 0.01 to about 50 parts, to one part LTD.sub.4 antagonist and wherein the PAF antagonist is 5-{3-[4-(2-chlorophenyl)-9-methyl-6H-thieno[3,2-f][1,2,4]triazolo[4,3-a][1 ,4]diazepin-2-yl]-2-propynyl}phenanthridin-6(5H)-one (E)-4-[3-[2-(4-cyclobutyl-2-thiazolyl)ethenyl]phenylamino]-2,2-diethyl-4-o xobutanoic acid and an inert pharmaceutical carrier.

2. A method of treating allergic reactions which comprises administering to a host requiring such treatment a composition comprising an effective amount of a PAF antagonist and an effective amount of a LTD.sub.4 antagonist, wherein the PAF antagonist is 5-{3-[4-(2-chlorophenyl)-9-methyl-6H-thieno[3,2-f][1,2,4]triazolo[4,3-a][1 ,4]diazepin-2-yl]-2-propynyl}phenanthridin-6(5H)-one (E)-4-[3-[2-(4-cyclobutyl-2-thiazolyl)ethenyl]phenylamino]-2,2-diethyl-4-o xobutanoic acid.