Epinephrine Bitartrate Research Articles

Direct Spectrophotometric Assay of Quaternary Ammonium Compounds Using Bromthymol Blue

Benzalkonium chloride, benzethonium chloride, and chlorhexidine gluconate were assayed quantitatively by a direct spectrophotometric method with bromthymol blue buffered at pH 7.5. The method shows good results at concentrations of 0–300 μg/ml and in the presence of epinephrine bitartrate, phenylephrine hydrochloride, pilocarpine hydrochloride, and polyvinyl alcohol.

Some effects of topically applied (−)-adrenaline bitartrate on the rabbit eye

A 2·5% solution of thymoxamine hydrochloride applied topically to the eyes of conscious rabbits did not affect ocular tension. When 2·5% thymoxamine was administered prior to 0·5% adrenaline, a decline in ocular tension commenced 1–2 hr after adrenaline, in contrast to the observation with 0·5% adrenaline alone in which tension remained unchanged for 2 hr after administration. Topical adrenaline solutions of several concentrations were shown to reduce penetration of tritiated water from the blood into the aqueous humour of conscious rabbits and also to reduce the clearance of [ 14C]inulin injected into the anterior chambers of conscious and anaesthetized rabbits. However, these effects were short-lived, being negligible after approximately 2 hr and absent after 4 hr. Another early effect of adrenaline observed in conscious rabbits was a concentration-related decrease in the anterior chamber depth. Experiments performed on anaesthetized rabbits showed a correlation to exist between the magnitudes of facility increases and ocular tension reductions observed after the topical administration of 0·5% adrenaline. The discussion suggests that the reduction of ocular tension present 4–5 hr after topical administration of adrenaline in the rabbit is mainly due to increased outflow facility. It is further suggested that the delay in onset of the hypotension is due to a hypertensive mechanism which temporarily negates the potentially hypotensive effects of increased facility and decreased aqueous inflow.

Effect of Epinephrine on the Corneal Endothelium

Intracameral epinephrine has been advocated for treatment of iris bleeding and inadequate pupillary dilatation during intraocular surgery. Commercial epinephrine 1:1000 with its preservative sodium bisulfite damaged corneal endothelial function and ultrastructure in rabbit and monkey eyes with sodium bisulfite the source of the damage. Endothelial damage can be prevented with a 1:5000 dilution of commercially available epinephrine in 0.1% sodium bisulfite or freshly prepared epinephrine bitartrate 1:1000 with a bicarbonate Ringers.

Some responses of the rabbit eye to topically administered (−)-adrenaline bitartrate

Propranolol (0·25%) administered topically to each of six conscious rabbits prevented the initial rise in ocular tension normally seen after topical application of 10·0% adrenaline. Neither 0·25% nor 0·5% propranolol affected the delay in onset of hypotension after 0·5% adrenaline applied topically to eyes of eight rabbits. In experiments to determine possible effects of tonometry procedures, including local anaesthesia, on the responses to 0·5% adrenaline, normality of two groups of eight rabbits was first assessed by preliminary study of their responses to topical 0·5% adrenaline. Seven days later one group was given 0·5% adrenaline in one eye of each animal, and a single determination of tension was made at 2 hr 20 min. Treated and control eyes had similar tensions. The other group had 0·5% adrenaline administered to both eyes of each rabbit at time 0, and to one eye of each rabbit at 3 hr. The first tonometry was performed at 4 hr, and at 5 hr tensions in twice treated eyes were significantly higher than those in eyes given a single treatment. Facility determinations on rabbits anaesthetized with urethane showed that topical 0·25 and 0·5% adrenaline produced increases apparent 50 min after administration, in contrast to 1·0, 2·5 and 5·0%. Responses to 0·5% were not significantly larger at 4 hr 20 min than they were at 50 min or 2 hr 20 min. At 4 hr 20 min concentration-related increases were apparent with 0·25-5·0% treatments, and determinations at 6 hr 20 min showed significantly lower effects with 0·5, 1·0 and 5·0% than those seen at 4 hr 20 min. Second adrenaline treatments with 0·5 or 1·0% 3 hr after an initial treatment with 0·5% adrenaline did not cause significantly different facility values at 4 hr 20 min compared with eyes treated with 0·5% adrenaline at time 0 only.

The effect of topically applied guanethidine sulphate on pupil and tension responses of the rabbit eye to (−)-adrenaline bitartrate

Five per cent guanethidine sulphate applied topically twice daily for 7 days to one eye of each of a group of eight rabbits produced a significant miosis and hypotension in the treated eyes. The hypotensive effect of 0·25% (−)-adrenaline bitartrate was augmented in the eyes which had received guanethidine and also in the opposite eyes, although mydriatic effect was increased in the guanethidine treated eyes only. Three per cent guanethidine in a similar experiment gave a slight miosis, and significant augmentation of the pupil response to 0·25% adrenaline. It did not significantly alter the tension, or response of tension to adrenaline in either eye. Repeated daily administration of 5% guanethidine plus 0·25% adrenaline initially caused augmented tension and pupil responses to adrenaline, but by day 21 the responses were not greater than controls. These results are compared with published human data.

Acetylcholine release from the rabbit isolated superior cervical ganglion preparation.

1. The rabbit isolated superior cervical ganglion preparation has been used to measure the release of acetylcholine from the tissue at rest and during preganglionic nerve stimulation.2. In the presence of physostigmine, the resting release of acetylcholine was 0.13 +/- 0.01 (nmol/g)/min (10 experiments) and that during stimulation with 300 shocks at 10 Hz was 3.1 +/- 0.4 (pmol/g)/volley in 4 experiments (means +/- S.E.M.). The volley output was independent of the frequency of stimulation over the range 1 to 10 Hz but was higher at 0.3 Hz.3. Tetrodotoxin, 0.8 muM, had no effect on the resting release of acetylcholine but reduced the stimulated release below detectable levels (2 pmol). Lowering the temperature of the bathing fluid to 5 degrees C reduced to below detectable levels both the resting release and that produced by nerve stimulation.4. The resting release of acetylcholine was increased by a potassium-rich (49.4 mM K(+)) bathing solution and by replacing the sodium chloride in the solution with lithium chloride (113 mM Li(+)).5. (-)-Noradrenaline bitartrate, 3 muM, and (+/-)-adrenaline bitartrate, 1.5 muM, reduced by 70% the output of acetylcholine induced by stimulation at 0.3 Hz, but failed to reduce the resting release or that evoked by stimulation at 10 Hz. The inhibition was reversed by phentolamine.6. It is concluded that the rabbit superior cervical ganglion in vitro is a suitable preparation for studying transmitter release and that the ganglion blocking effect of catecholamines is due to a reduction in transmitter release.

Adenosine 3',5'-cyclic monophosphate phosphodiesterase in guinea-pig lung—Properties and effect of adrenergic drugs

The hydrolysis of adenosine 3',5'-cyclic monophosphate (cAMP) by adenosine 3',5'-monophosphate phosphodiesterase (PDE) was studied in whole homogenates and cell fractions of guinea-pig lung. Approximately 60 per cent of the activity of the whole homogenate was contained in the 10,000 g supernatant. This cell fraction contained PDE with two separate affinities for cAMP: PDE I with low affinity. K m ≅ 3.1 × 10 −4 M; V max ≅ 90 nmoles cAMP hydrolyzed/mg protein/20 min and PDE II with high affinity K m ≅ 5.7 × 10 −5 M; V max ≅ 35 nmoles cAMP hydrolyzed/mg protein/20 min. Both forms required magnesium which could be replaced by manganese and cobalt but not by copper. Aminophylline and theophylline inhibited both PDE forms. Calcium only inhibited PDE I but not PDE II. Adrenergic drugs inhibited PDE I and at 0.1 mM decreased in potency in the following order: isoproterenol  epinephrine > norepinephrine > methoxamine. Butoxamine was ineffective on PDE I. Only norepinephrine inhibited PDE II but not to the same extent as its effect on PDE I. Chelation of added magnesium and endogenous calcium was not responsible for the inhibition of PDE I by the adrenergic drugs used. Propranolol (0.1 mM) and phentolamine (0.05 to 0.001 mM) alone did not effect PDE I. Propranolol (0.1 mM) failed to reverse the inhibitory effect of isoproterenol (0.1 mM) and epinephrine (0.1 mM). Thus a β-adrenergic mechanism could not explain the inhibitory effect of these agents. Phentolamine (0.05 to 0.001 mM) reversed the inhibition by epinephrine bitartrate but not by epinephrine hydrochloride. These data are inconclusive to support an α-adrenergic mechanism for the inhibition of cAMP phosphodiesterase by epinephrine.

Synthesis and Formulation of Several Epinephrine Salts as an Aerosol Dosage Form

A satisfactory method for the preparation of various salts of epinephrine such as the maleate, malate, and fumarate was developed. Following the synthesis of these salts, a study of the partition coefficient of these salts in higher molecu1ephrine bitartrate in these same vehicles. The solubility of these new salts in chloroform, carbon tetrachloride, and fluorinated hydrocarbons was then determined. Several systems incorporating these new salts were prepared and subjected to a preliminary stability study. The partition coefficient of epinephrine maleate determined between octyl alcohol-water and hexadecyl alcohol-water was found to be higher than the value for epinephrine bitartrate, malate, and fumarate. The solubility of epinephrine maleate and fumarate in four propellants (dichlorodifluoromethane, dichlorotetrafluoroethane, monochlorodifluoroethane, and difluoroethane) was found to be slightly higher than the epinephrine bitartrate and malate. As expected, difluoroethane dissolved the highest amount of epinephrine salts as compared to the other propellants studied. Epinephrine maleate and bitartrate were found to have greater stability than the epinephrine malate and fumarate compounds on the basis of the preliminary stability study.

Corneal pigment deposits from topically administered epinephrine. Experimental production.

Instillation of epinephrine bitartrate, borate, and hydrochloride solutions in various clinically used strengths failed to produce corneal melanin pigmentation in rabbit eyes. Continuous exposure to the experimental drug using saturated Czech soft gel contact lenses also failed to induce pigmentation in the intact rabbit cornea. Repeated elevation of intraocular pressure by subconjunctival injection of hypertonic sodium chloride solution and abrasion of corneal epithelium resulted in pigment deposition. The appearance of pigment was obtained very much earlier with the use of oxidized epinephrine preparations. In the earliest stages, the pigment was detected only by histological examination. At later stages, slit-lamp biomicroscopy revealed the pigmentation, which eventually could be recognized on gross inspection.

The water-loading test in rabbits. A method to detect potential ocular hypotensive drugs.

Tap (100 ml/kg) was administered by oral gavage to normal adult rabbits. Significant elevation of the intraocular pressure (IOP), lasting for at least 30 minutes, was observed. Following topical treatment, the IOP was significantly reduced by epinephrine bitartrate, carbachol, isoproterenol bitartrate (Isolevin [Britain]), hexamethonium chloride, propranolol hydrochloride, pilocarpine hydrochloride, and physostigmine salicylate, but not by phenoxybenzamine hydrochloride or atropine sulfate. Oral administration of dichlorphenamide or acetazolamide, three hours prior to water loading, resulted in a lower IOP than that observed for normal control animals. Based on these data, the water-loading test in rabbits appears to represent a valid procedure for screening drugs with potential antiglaucoma activity.

Suppression of portal venous insulin concentration by epinephrine i the conscious monkey.

Conscious male rhesus monkeys were given epinephrine bitartrate (1 μg/kg.min) through a catheter implanted in the right internal jugular vein. Blood samples were taken from the portal vein through another catheter before, during, and after a 15-minute-long jugular infusion. Sugar in the plasma rose during, and was still high 10 min after the infusion, while mean immunoreactive insulin decreased during the infusion and rose dramatically after its termination. Ergotamine tartrate (14 μg/kg.min) while not preventing a rise in plasma sugar concentration, inhibited the expected insulin decrease during epinephrine infusion.

The interactions of local guanethidine and sympathomimetic amines in the human eye.

The responses of the human eye to the intraocular administration of the adrenergic neurone blocking drugs guanethidine sulfate and debrisoquin sulfate have been investigated by photographically recording the pupillary changes. After protracted treatment with local guanethidine sulfate (100 mg/ml), the mydriatic action of phenmetrazine hydrochloride, amphetamine sulfate, hydroxyamphetamine hydrobromide, ephedrine hydrochloride, and tyramine hydrochloride was abolished and that to methoxamine hydrochloride, epinephrine bitartrate, and phenylephrine hydrochloride potentiated. Following chronic debrisoquin (20 mg/ml) the mydriatic responses to phenylephrine and ephedrine were potentiated. These results indicated that guanethidine exhibits pharmacological actions which parallel postganglionic sympathectomy, while debrisoquin mimicks preganglionic sympathectomy.

WHAT'S THE ANGLE ON MYDRIASIS?

To the Editor. —The fact that cycloplegics may cause a significant elevation in the intraocular pressure of some normal eyes and some eyes with open-angle glaucoma in the absence of angle closure has received further documentation by the careful study reported by L. S. Harris (Cycloplegic-Induced Intraocular Pressure Elevations, Arch Ophthal 79: 242-246 [March] 1968). The effect of 10% phenylephrine, a commonly used mydriatic, upon intraocular pressure is less clearly defined. Several investigators 1-4 have reported phenylephrine has no effect upon intraocular pressure in open-angle glaucoma. Conversely, Lee 5 reported the paradoxical rise of intraocular pressure of some patients with open-angle glaucoma following instillation of 1% epinephrine or 10% phenylephrine. In these cases outflow facility was decreased without gonioscopically visible closure of the anterior chamber angle. In a personal study of 21 patients with open-angle glaucoma under medical treatment (pilocarpine, anticholinesterases, epinephrine bitartrate, and carbonic anhydrase inhibitors, singly or

Horner's Syndrome

A study has been made of the response of the iris and the intraocular dynamics in three human subjects with unilateral Horner's syndrome that ranged in duration (since onset) from a few months to many years. It is shown that adrenergic denervation supersensitivity to epinephrine bitartrate may persist for over 20 years. Adrenergic supersensitivity was absent in one subject, and reasons are presented for believing that this is indicative of a preganglionic cervical sympathetic lesion. On the basis of these studies a means of differentiation between preganglionic and postganglionic cervical lesions is proposed. The method is believed to be more specific and less open to misinterpretation than that in current usage.

Norepinephrine elicitation of aggressive display responses in Betta splendens

From arguments elucidated by D. H. Funkenstein and others, it was hypothesized that the aggressive display of the Siamese fighting fish was under hormonal (i.e., norepinephrine) control. Fighteen visually isolated fish were observed for 10 min. each under a plain water control condition and with norepinephrine bitartrate solutions in their individual living tanks. Significant increases in the frequency of fin extensions and gill flaring responses, as well as increased coloration were found for the drug group. Six fish treated with epinephrine bitartrate resembled fish under the control condition except for color change; all six bleached during observation.

Lenticular Opacities Induced in Mice by Chlorpromazine

Granular changes are seen in the lens and cornea of some patients given large doses of chlorpromazine. 1 The changes in the lens resemble the lenticular opacities induced in mice by the administration of narcotics of the morphine class 2 and by catecholamines. 3 This report describes the formation in mice of lenticular opacities after chlorpromazine treatment. Attempts to block development of the cataract by sympatholytic compounds are discussed in relation to the effects of these compounds on opacities induced by catecholamines and narcotics. Materials and Methods Female Swiss-Webster mice, weighing 20 to 25 gm, were used throughout. All injections were given intraperitoneally in volumes between 0.1 and 0.2 ml except where indicated. Chlorpromazine hydrochloride (molecular weight, 355.3) was used as the commercially available preparation; epinephrine bitartrate (USP) and the levorphanol bitartrate were prepared before each use. The e inephrine solutions were administered in two stages, about 10% of the

OUTFLOW IN GLAUCOMA

To the Editor: —The article Improvement of the Coefficient of Outflow in Glaucomatous Eyes by E. J. Ballintine and L. L. Garner, which appeared in the September issue of theArchives of Ophthalmologycontained 2 errors which I would like to correct. In the first paragraph, the fifth and sixth lines read reasonably stable preparations of racemic epinephrine bitartrate and l -epinephine. These lines should read reasonably stable preparations of l -epinephrine bitartrate and l -epinephrine hydrochloride. Similarly, on p. 315, first column, line 25 reads number of patients used racemic epi-. This line should read number of patients used l -epi-.

Improvement of the co-efficient of outflow in glaucomatous eyes. Prolonged local treatment with epinephrine.

Epinephrine and other sympathomimetic amines have been used in the treatment of various forms of glaucoma for at least 30 years. Within the last 4 years uniform and reasonably stable preparations of racemic epinephrine bitartrate and l -epinephrine hydrochloride have become available widely for clinical use. When tonography was performed on patients in whom the intraocular pressure (IOP) had been lowered by the addition of one of these preparations to the therapeutic program, in the first few weeks the lowering of the pressure was in most cases the result of a reduction in the rate of production of aqueous humor. This effect has been described most recently by Becker and Ley. When the epinephrine treatment was continued for a period of weeks or months, a different effect was observed in that the pressure remained low and the facility of outflow (C) became larger. In a majority of the patients so treated,

Conjunctival Reaction Due to l-Epinephrine Bitartrate (Epitrate)

No report can be found in the contemporary ophthalmic literature of an irritative conjunctival reaction due to the use of l -epinephrine bitartrate (Epitrate) solution. This report describes such a reaction in a patient who was being treated for chronic simple open-angle glaucoma. The distinguishing characteristics of an irritative conjunctivitis and allergic dermatoconjunctivitis will be outlined. The probable mechanism for this particular reaction and the atypical findings will also be cited. Report of a Case A white woman, 53 years old, has been treated in the outpatient clinic of The New York Eye and Ear Infirmary since August, 1954, for chronic simple open-angle glaucoma. The diagnosis was based on a positive water drinking test. The use of pilocarpine drops 1% t.i.d. O.U. did not reduce her intraocular tension, so the strength was increased to 2% t.i.d. O.U. This dosage stabilized her tension at a satisfactory level for the ensuing two

Demecarium bromide and echothiophate iodide in chronic glaucoma.

Demecarium bromide (BC-48 or Humorsol) and echothiophate (Phospholine) iodide are potent long acting inhibitors of cholinesterase. 1-5 They improve outflow facility and lower intraocular pressure in both normal and glaucomatous eyes. 6,7 In contrast to isoflurophate (DFP), they are water soluble and more stabile. The present study is an evaluation of these agents in a series of patients with glaucoma uncontrolled on other forms of therapy. Method All patients selected for these series had been on various other forms of therapy (pilocarpine, carbachol, physostigmine, epinephrine bitartrate, carbonic anhydrase inhibitors) and had been judged to be unsuccessfully controlled (intraocular pressure over 24 mm. Hg). Demecarium bromide therapy was initiated in 144 eyes of 76 patients; and echothiophate iodide was started in 155 eyes of 83 patients.* As indicated in Table 1, chronic simple glaucoma predominated in both series with a small number of secondary and postoperative (iridectomy) angle-closure glaucomas. Patients were