Fluid therapy with L-lactate and/or pyruvate anions

Abstract: Processes and compositions are provided for accom­ plishing fluid therapy using the anions l-lactate, pyruvate, d-betahydroxybutyrate, acetoacetate, or mixtures of such. The racemic d,l-lactate or acetate anion mixtures heretofore used in fluids are now known not to be desirable because they cause adverse and toxic effects when administered to mammals.

Description: Field of the Invention This invention lies in the field of fluid therapy in humans, and more particularly in the field of aqueous solutions for parenteral, oral, dialysis, and irrigation therapy which employ d-betahydroxybutyrate anions in combination with selected cations. Prior Art Previously, I have provided improved electrolyte solutions for in vivo and in vitro usage which contain l-lactate and pyruvate anions, and/or d-betahydroxybutyrate and acetoacetate anions In respective defined ratios in combination with defined Na:Cl ratios; see my US Patents 4883188, 4663289, 4694050 and 4668400 issued on 5 May 1987, 8 May 1987, 10 March 1987 and 26 May 1987, respectively. However, it is now appreciated that the benefits of using d-betahydroxybutyrate anions need not be restricted by these previously taught relationships of anion pair ratios to Na:Cl ratios. Previously, only racemic mixtures of lactate anions containing both d- and I-forms of lactate have been used in aqueous solutions for human parenteral therapy. The other major organic anion used in human parenteral fluids has been acetate. So far as is now known, the natural l- form of lactate anion has heretofore never been used, apart from the unnatural d- form, in human fluid therapy. Sodium lactate solutions, used in pharmaceutical practices, are not specified in terms of isomeric structure. In the U.S. and British Pharmacopeias, lactate is defined and approval was duly granted for use of the d,l-lactate mixture. Hence, the d,I-lactate is the form used in contemporary pharmaceutical practice. The I-lactate is recognized to be the physiologically predominant form which is metabolized by different pathways and with different effects than is the d-lactate. The toxicity of d-lactate has been described in humans (see Oh MS et al N Eng J Med 301 : 249-251, 1979; Perlmutter, DH et al J Pediatrics 102 : 234-238, 1983; Stolberg, L et al N Eng J Med 306 : 1344-1348, 1982). Thus, the d- form has now been discovered to cause adverse and toxic effects when administered to mammals. For example, when an aqueous 20 mM/l d-lactate (or d-lactic acid) is administered parenterally to a rat, swelling of brain tissue is observed because the brain takes in the slowly metabolized d-lactate - plus an equivalent amount of K + . With continued administration, coma develops, the cerebral edema worsens and death ensues. In contrast, when I-lactate is similarly administered, the differential concentration of I-lactate between intracellular and extracellular fluid does not cause coma or death. For another example, Veech et al . (Veech, RL and Fowler, RC., "Cerebral Dysfunction and Respiratory Alkalosis During Peritoneal Dialysis with d-Lactate Containing Peritoneal Dialysis Fluids". Am. J. Med., 1987 (in press)) points out that the severe recurrent metabolic alkelemia described by Kenamond et al. ("Severe Recurrent Alkalemia in a Patient Undergoing Continuous Cyclic Peritoneal Dialysis". Am. J. Med., 548-550, 1986) was secondary to an encephalopathy caused by the inclusion of d,l-lactate in routine dialysis fluids. Because of such encephalopathological results, parenteral solutions containing the racemic d,l-lactate anions should not be administered for therapeutic purposes. All previous commercial formulations of fluids for human therapy use lactate or lactic acid in the racemic d,l form as defined in the United States or British Pharmacopeia (see the United States Pharmacopeia 21st edition, January 1985, p 581, 945-946, 1186; United States Pharmacopeia Convention, Rockville, and British Pharmacopeia 1980, p 250, 666, 667, Her Majesty's Stationary Office, London). Sodium d,l-lactate solutions are currently and conventionally used for three major purposes in current medical practice. First, sodium d,l-lactate solution is used parenterally as an alkalinizing agent to correct acidosis. Secondly, it is used in parenteral fluid therapy to normalize the Na:Cl ratio from the 1:1 ratio found in normal saline. Thirdly, it is used as the counter ion in peritoneal dialysis solutions. In addition, it could also be used in current hemodialysis to replace the acetate anion, or, in its H + form, as an acid to be added to a bicarbonate hemodialysis fluid. Prior to the teachings contained in my US Patent 4663166, pyruvate anions, d-betahydroxybutyrate anions, and acetoacetate anions in aqueous solution, so far as is now known, were never used in human therapeutic fluids. BRIEF SUMMARY OF THE INVENTION The scope of the present invention is defined in the claims of this specification, to which reference should now be made. This invention thus relates to fluid compositions for accomplishing fluid therapy without encephalopathy or metabolic bone disease and other complications resulting from use of present fluid formulations In a living human involving the introduction into the body of such human an aqueous solution containing a permeant mono-anionic metabolite which is d-betahydroxybutyrate anions. Here, I-lactate is defined as that form of lactate anion found in mammalian tissues and designated l or L-lactate. It is identified by its ability to react with NAD + to form pyruvate in a reaction catalyzed by mammalian lactate dehydrogenase (EC 1.1.1.27). The form of l-lactate which is dextrorotatory in aqueous solution is designated l-(+) while the salts of l-lactate which in aqueous solution are levorotatory are designated I-(-)lactate (see US Dispensatory. Osol, A, Pratt, R, Gennar, AR,, eds. p 658. JR Lippcott. Philadelphia, 1973). Pyruvate and acitoacetate have no sterospecificity. More particularly, this invention is directed to stable fluids for conventional administration to humans such as, (a) oral ingestion of an aqueous solution (b) parenteral therapy involving, for example, the intravenous administration of an aqueous solution (c) dialysis therapy (hemo or peritoneal) using aqueous solutions (d) dialysis therapy (hemo or peritoneal) where acetic acid is replaced with d-betahydroxybutyrate and/or (e) irrigation therapy. Thus, surprisingly, encephalopathy, metabolic bone disease, and many other complications are completely avoided by using d-betahydroxybutyrate in place of racemic d-l-lactate in solutions employed in fluid therapy, does not cause any change in the heretofore known beneficial physiological or pharmacological effectiveness of such fluids. In general, a solution containing d-betahydroxybutyrate is administerable for generally the same purposes that prior art parenteral fluids or dialysis fluids are used which contain racemic d-l-lactate anions. For examples, such a solution can be used to treat acidosis other than diabetic Ketoacidosis, dehydration, blood electrolyte depletion, shock, malnutrition and uremia. Because mixtures of l-lactate anions and pyruvate anions, and mixtures of d-betahydroxybutyrate anions and acetoacetate anions, in solutions each constitute near-equilibrium couples, which can vary widely in concentration under normal physiological conditions, as explained, for example, in my US Patent 4663166, these anions can be employed with little or no adverse side effects in parenteral fluids. Moreover, the therapeutic use of these anion couples (a) tends to maintain a normal plasma milliequivalent ratio of sodium cations to chloride anions, (b) thus tends to prevent hyperchloremic acidosis, and (c) accomplishes electrolyte and fluid and resuscitation therapy. The anions taught by this invention permit one to avoid the known untoward effects of high levels of the d-lactate anion (see Veech, RL, Fowler, RC, op. cited above) or of acetate anion which are now the major organic anions conventionally added to parenteral fluids (See Veech RL. The toxic impact of parenteral solutions on the metabolism of cells: a hypothesis for physiological parenteral therapy. Am J Clin Nutr 44: 519-551, 1986). Other and further objects, aims, purposes, features, advantages, embodiments and applications will be apparent to those skilled in the art from the teachings of the present specification taken together with the claims. DETAILED DESCRIPTION For the fluid therapy purposes of my present invention, any conventional administration procedure is suitable, although parenteral (particularly intravenous) administration during hemo or peritoneal dialysis is presently preferred. In practice, the calculation of the quantity of an alkalizing infusion solution required for adults is based on an average value for the water content of the body of 50% by weight and on a uniform intra- and extracellular distribution of d-betahydroxybutyrate. This method naturally yields only rough figures. The calculation can be simplified by reckoning in milliequivalents desired change in the alkali reserve. For example, in order to increase or decrease the alkali reserve in a patient weighing 70 kg by 5 mEq, a quantity of d-betahydroxybutyrate anions of 70×6×0.5 = 210 mEq must be administered. In order to avoid the danger of an acidosis becoming converted into an alkalosis, it is advisable not to attempt a complete normalization of the alkali reserve by means of an alkalizing solution, and such solutions should never be administered without supplementary potassium. In children, a higher water content of about 66% must be reckoned with, so that the calculation yields relatively high infusion quantities. The differences between the calculated and observed effects of alkalizing and of acidifying compounds can be considerable since the above approximate calculation ignores a number of important factors. In diabetic acidosis, many authors consider it is inadvisable to administer large quantities of sodium salts without potassium salts. On the other hand, extremely good results have been reported in the intensive lactate treatment of diabetic coma. There is no doubt that a moderate alkali therapy with I-lactate and/or pyruvate is indicated in diabetic ketosis with very much lowered alkali reserve, since it has been shown that insulin activity is inhibited by acidosis and that acidosis increases the blood sugar. Clearly use of d-betahydroxybutyrate would not be suitable for use in diabetic ketoacidosis. As those skilled in the art will also appreciate, the ketone bodies would not be appropriate for use in pregnant women. When using solutions such as "Lactated Ringer's" (see, for example, my US Patent 4663166) replete body water and electrolytes, the 28 mM d,l-lactate of the prior art is replaced with, for example, 28 mM l-lactate. In this way, the Na:Cl ratio, In such an I-lactate solution, is moved, if desired, towards a normal ratio of 1.36 as found in normal human plasma. Thus, hyperchloremic acidosis resulting from large infusions of normal sodium chloride solutions is avoided. The same considerations apply to use of such solutions in dialysis (see, for example, my US Patents 4663168 and 4688400). A preferred application for this invention involves usage of d-betahydroxybutyrate as indicated, in solutions. conditions where long stability of mixed aqueous solutions presents a practical problem, use of d-betahydroxybutyrate alone confers stability on the solution and is to be preferred over the currently used d,I-lactate or acetate. In parenteral therapy, the total concentration of d-betahydroxylbutyrate can range from about 0.Ø1 to 2400, millimoles per liter, though larger and smaller quantities can be used depending upon circumstances. The rate of introduction into a human patient, and the dosage used, are generally the same as are conventionally used in solutions containing, for example, d,I-lactate. The d-betahydroxybutyric acid itself as such, may be used. For example, such can be used in combination with aqueous bicarbonate anions; for instance, in sodium bicarbonate containing solutions. Also, one can employ, in the starting solutions of the present invention, aqueous solutions which contain, along with d-betahydroxybutyrate at least one cation selected from sodium, potassium, calcium, magnesium, and ammonium. Inorganic physiologically acceptable anions, besides bicarbonate, may also be present, such as chloride, phosphate, and sulfate, if desired, and if such are present, the respective quantities present are preferably similar to corresponding physiologic levels. A difference between the total milliequvalents of the cations present in a solution and the total milliequivalents of the organic anions of the specified group employed in the practice of this invention (d-betahydroxybutyrate) can be provided by other physiologically acceptable anions. It is considered to be physiologically advantageous and it is generally preferred in the practice of this invention, to maintain the levels of the respective organic metabolite anions employed at values which are approximately physiologic. Also, when a mixture of the monocarboxylic metabolic anions is employed in a given solution, It is not necessary to employ redox couple anion pairs since this use of these defined monocarboxylic metabolite anions does not produce the toxic effects resulting from the present use of d,I-lactate or acetate. Further, it appears to be desirable to employ such anionic metabolites in combination with bicarbonate anions in conditions where large volumes of fluid are to be used and administration of calories is not desired, such as in peritoneal dialysis. Additionally and preferably, such a solution may contain dissolved therein at least one osmotically active, substantially nonionic substance in accord with, for example, teachings for prior art d,l-lactate and acetate containing solutions. Examples of suitable such nonionic substances include glucose (preferred), fructose, glycerol and sorbitol. Typically, and preferably, such a solution has an osmolarity ranging from 240 to 2400 mOsmoles/liter. In addition, formulations containing ionic nutrients, such as l- amino acids, can benefit from the addition of at least one of the metabolite monocarboxylic acid anions taught herein. For example, the acetate anions present in current commercial amino acid formulations (which lead to metabolic bone disease) can be replaced by such anions. See, for example, my copending U.S. patent application Serial No. 810,916, filed Dec. 18, 1985, and its continuation-in-part application filed on even date herewith. Also preferably, a starting solution used in the practice of this invention has a pH in the range from 5 to 9, although for the contemplated human usage, a most preferred pH is 7.4. Additional cations and anions may be present in a starting solution as taught, for example, in my US Patent 4663166. Thus, and as indicated above, such a solution can additionally contain bicarbonate anions. The pH of the resulting solution is adjustable to a desired value, such as a preferred value in the range from about 6 to 8.4, by the addition of the hydrogen form of d-betahydroxybutyric acid in an amount sufficient to give such desired value. For example, when an anion of an acid such as I-lactic acid, pyruvate acid, d-betahydroxybutyrate acid is to be added to a bicarbonate containing starting solution, a desired pH of such solution for use in human hemodialysis, is given by following the formula: pH = pK a' - log [HCO 3 - ] 2([HCO 3 - ]-[HA]) - 1 2 where: HA is the concentration of carboxylic acid in moles/liter, pK a , = 6.10 at 38°C (see Hastings, AB, et al., J. Biol. Chem. 79:183-192, 1928). In preferred applications of this sort, such as applications which can incorporate from 28 to 40 mM/l HCO 3 - , 2 to 9 mM/l d-betahydroxybutyric acid may generally be added. Such solutions are presently preferred for peritoneal or hemodialysis over existing fluids containing acetic acid or d,l-lactate because of the toxicity of the presently used acids. Optionally, carbon dioxide may additionally be dissolved In such a solution, for example in the range such as taught in my US Patent 4663166. The practice of the methods of this invention does not require, in any given starting solution, both members of a redox active, near-equilibrium monocarboxylic acid couple; either member can be used individually. Also, such practice does not require the use-of a narrowly specifed range of Na + to Cl - milliequivalent ratios (when such inorganic ions are both present). Thus, as taught herein, therapy (including correction of acidosis other than diabetic Ketoacidosis dialysis and/or fluid, electrolyte or nutrient replacement in accord with the present invention can be accomplished through the use of the anion herein taught in a starting solution wherein the cations are selected from among hydrogen, sodium, potassium, calcium, magnesium, and ammonium. In the practice of this invention only one monoanionic permeant metabolite (l-d-betahydroxybutyrate is present in a solution. Thus, for example, one class of solutions, which has characteristically long shelf life and stability, contains as anions only d-betahydroxybutyrate anions and is termed herein Class for convenience. This class is particularly useful where long term fluid storage is desirable. Table I illustrates various embodiments of such exemplary classes. Range of Concentration in mMoles/Liter Item No. Component Class I 1 betahydroxybutyrate 0.1-2400 2 (cations) 10 -5 -10 -9 (hydrogen) 0-2400 sodium 0-2400 potassium 0-1200 calcium 0-1200 magnesium 0-1200 ammonium 0-10 Table II describes four classes of physiologic permeant monoanionic metabolite solutions suitable for each of three major fields of application. The genus class is described In Type A solutions of Table II, where d,l-lactate was previously used, and such improved solutions are suitable for use in treatment of certain forms of metabolic acidosis. For oral or parenteral use in resuscitation or the treatment of acidosis or severe fluid loss in diarrhea, the milliosmolarity of the solutions can vary widely from 240 mOsmoles/L to 4800 mOsmoles/L. Prior art hypertonic sodium chloride solutions or hypertonic Ringer's lactate solutions have been widely used in resuscitation; such solutions can be reformulated as Type A solutions of this invention. Type B solutions of Table II are suitable for rehydration, electrolyte replacement, and/or nutrition. Type C solutions of Table II, are suitable for use as peritoneal dialysis and hemodialysis fluids. Type D solutions can be regarded as being similar in use to Type C solutions, but such include the permeant monoanionic metabolites in their hydrogen form in solutions which contain bicarbonate so as to achieve a desired pH in a manner which avoids the current toxic effects of high levels of acetate or d,l-lactate. These class D solutions are particularly suitable for use where it is desirable to avoid high levels of monocarboxylic acids. By using normal metabolites, these new fluids improve the corresponding prior art fluids, such as Ringer's lactate and hemodialysis fluids. With appropriate dosage, these fluids are also suitable for oral ingestion, such as under conditions requiring therapy where close patient monitoring is not possible. For example, one can accomplish treatment of, metabolic acidosis, other than diabetic Ketoacidosis or resuscitation with improved sodium Hactate or other Type A solutions as described in Table II. For treatment of acidosis, initial parenteral administration followed by oral administration is often preferred. For example, one can accomplish parenteral fluid therapy with improved Hactated Ringer's-type solutions (Type B) using the present invention in a human patient suffering from fluid, electrolyte, and/or nutritional depletion. Such a fluid may optionally contain non-ionic dissolved nutrients, usually glucose, from 0 to 280 mmoles/liter. For another example, one can accomplish dialysis fluid therapy with an improved dialysis solution (Type C) using the present invention in a living human patient. The conventional techniques of hemo- and peritoneal dialysis known to the prior art are employable with the improved fluids of this type. Thus, the renal function of a living human patient is replaced at least in part by passing the blood of the patient over one face of a dialysis membrane while a dialysis fluid is passed over the opposite face of such membrane. In hemodialysis, it is preferable to use a dialysis solution of Type D containing from 20 to 55 mM/l of bicarbonate anions, such solution also contains a sufficient portion of d-betahydroxybutyrate which is derived from the addition to said solution of d-betahydroxybutyric acid in a total amount which is sufficient to produce a pH in the range from 5.5 to 8.2, such solution also has a milliosmolarity of from 250 to 310 mOs/l. Similarly, when peritoneal dialysis is being practiced, a Type D solution containing bicarbonate can be used and the carboxylic metabolite acid material(s) as above described is/are (as the case may be) also present, but here in an amount sufficient to produce a pH ranging from 5.5 to 7.5. The milliosmolarity ranges from 280 to 550 mOs/l achieved by disolution in such solution of sufficient nonionic nutrients. Type D solutions are also adapted for parenteral administration, and for such purposes, a suitable composition of Type D is similar to that above indicated for peritoneal dialysis. suitable It will be appreciated that the designation mM and mM/l are used herein in their conventional manner to designate millimoles per liter. Preferred Solutions (New) units in mMoles/Liter solution Component Type A Type B Type C Type D Cations Na + 0 - 2400 130 - 160 130 - 145 130 - 145 K + 0 - 60 2 - 10 0 - 4 0 - 4 Ca 2+ 0 - 4 0.5 - 2.5 0.5 - 2.0 0 - 2 Mg 2+ 0 - 3 0 - 1.5 0 - 1.0 0 - 1 Anions Cl - 0 - 2000 90 - 115 90 - 120 95 - 110 HC0 3 0 - 2000 0 0 - 40 20 - 55 Pi -1.8 0 - 50. 0 0 SO 4 2- 0 - 1.2 0 d-lactate 0 0 0 acetate 0 0 0 l-lactate 0 0 0 0 pyruvate - 0 0 0 0 d-betahydroxybutyrate - 0.1 - 2400 0.1 - 55 0.1 - 55 0.1 - 20 acetoacetate - 0 0 0 0 Nonanionics Glucose 0 - 278 0 - 280 0 - 240 0 - 240 pH 5 - 8.2 6.0 - 7.5 5 - 8.2 5.5 - 8.2 It is to be understood that the invention is not limited to the features and embodiments hereinabove specifically set forth, but can be carried out in other ways and manners.

Claims: Use of a fluid composition comprising water having dissolved therein the following components in the respective amounts indicated: Component Quantity (in mM) Cations Na + 0-2400 K + 0-60 Ca 2+ 0-4 Mg 2+ 0-3 Anions l-lactate - 0 pyruvate - 0 d-betahydroxybutyrate - 0.1-2400 acetoacetate - 0 provided that the total amounts of d-betahydroxybutyrate anion and said cations are such as to achieve electrical neutrality in such given solution, and further provided that said solution has a pH ranging from 5 to 8.2, for the manufacture of a medicament for the treatment of metabolic acidosis others than diabetic Ketoacidosis in a living human. Use of a solution comprising water having dissolved therein the following components in the respective quantities indicated: Component Quantity (in mM) Cations Na + 130-160 K + 2-10 Ca 2+ 0.5-2.5 Mg 2+ 0-1.5 Anions Cl - 90-115 l-lactate - 0 pyruvate - 0 d-betahyroxybutyrate - 0.1-55 acetoacetate - 0 provided that in any given said solution, the total amount of said cations is such as to achieve electrical neutrality, and further provided that said solution has a pH ranging from 6.0 to 7.5, for the manufacture of a medicament for rehydration, electrolyte replacement and nutrition. Use of a solution comprising water having dissolved therein the following components in the respective amounts indicated: Component Quantity (in mM) Cations Na + 130-145 K + 0-4 Ca 2+ 0.5-2.0 Mg 2+ 0-1.0 Anions Cl - 90-120 l-lactate - 0 pyruvate - 0 d-betahydroxy- butyrate - 0.1-55 acetoacetate - 0 provided that in any given solution the total number of indicated cations present is such as to achieve electrical neutrality, and also provided that said solution has a pH ranging from 5 to 8.2, for the manufacture of a medicament for dialysis therapy. Use according to claim 3 wherein said solution additionally contains from 20 to 55 mM of bicarbonate anions and wherein said solution also contains a sufficient portion of d-betahydroxybutyrate anions which are derived at least in part from the addition to said solution of d-betahydroxybutyric acid in an amount which is sufficient to produce a pH in the range from 5 to 8.2, and said solution contains sufficient nonionic dissolved nutrients to achieve a solution milliosmolarity of from 250 to 550 mOsmoles/liter. Use according to claim 3 wherein said solution additionally contains from 20 to 55 mM of bicarbonate anions and wherein said solution also contains a sufficient portion of d-betahydroxybutyrate anions derived from the addition to said solution of d-betahydroxybutyric acid in an amount which is sufficient to produce a pH in the range from 5.5 to 7.5, and said solution also contains sufficient nonionic dissolved nutrients to achieve a solution milliosmolarity of from 260 to 550 mOsmoles/liter.

Inventors: BTG INTERNATIONAL LIMITED
Applicants: BTG INT LTD, BTG INTERNATIONAL LIMITED
Application year: 1986
Main classification: A61K33
IPC codes: A61K31, A61M1, A61K33