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For Use in Ophthalmology
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WARNING: PHYSICIANS SHOULD COMPLETELY FAMILIARIZE THEMSELVES WITH THE COMPLETE CONTENTS OF THIS LEAFLET BEFORE PRESCRIBING NEO-SYNEPHRINE. |
NEO-SYNEPHRINE hydrochloride, brand of phenylephrine hydrochloride ophthalmic solution, is a sterile solution used as a vasoconstrictor and mydriatic for use in ophthalmology.
NEO-SYNEPHRINE hydrochloride is a synthetic sympathomimetic compound structurally similar to epinephrine and ephedrine.
Phenylephrine hydrochloride is (-)- m -Hydroxy-(alpha)-[(methylamino)methyl] benzyl alcohol hydrochloride, and has the following structural formula:
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NEO-SYNEPHRINE possesses predominantly (alpha)-adrenergic effects. In the eye, phenylephrine acts locally as a potent vasoconstrictor and mydriatic, by constricting ophthalmic blood vessels and the radial muscle of the iris.
The ophthalmologic usefulness of NEO-SYNEPHRINE hydrochloride is due to its rapid effect and moderately prolonged action, as well as to the fact that it produces no compensatory vasodilatation.
The action of different concentrations of ophthalmic solutions of NEO-SYNEPHRINE hydrochloride is shown in the following table:
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Although rare, systemic absorption of sufficient quantities of phenylephrine may lead to systemic (alpha)-adrenergic effects, such as rise in blood pressure which may be accompanied by a reflex atropine-sensitive bradycardia.
NEO-SYNEPHRINE hydrochloride is recommended for use as a decongestant and vasoconstrictor and for pupil dilatation in uveitis (posterior synechiae), wide angle glaucoma, prior to surgery, refraction, ophthalmoscopic examination, and diagnostic procedures.
Ophthalmic solutions of NEO-SYNEPHRINE hydrochloride are contraindicated in persons with narrow angle glaucoma (and in those individuals who are hypersensitive to NEO-SYNEPHRINE). NEO-SYNEPHRINE hydrochloride 10 percent ophthalmic solutions are contraindicated in infants and in patients with aneurysms.
There have been rare reports associating the use of NEO-SYNEPHRINE 10 percent ophthalmic solutions with the development of serious cardiovascular reactions, including ventricular arrhythmias and myocardial infarctions. These episodes, some ending fatally, have usually occurred in elderly patients with preexisting cardiovascular diseases.
Exceeding recommended dosages or applying NEO-SYNEPHRINE hydrochloride ophthalmic solutions to the instrumented, traumatized, diseased or postsurgical eye or adnexa, or to patients with suppressed lacrimation, as during anesthesia, may result in the absorption of sufficient quantities of phenylephrine to produce a systemic vasopressor response.
A significant elevation in blood pressure is rare but has been reported following conjunctival instillation of recommended doses of NEO-SYNEPHRINE 10 percent ophthalmic solutions. Caution, therefore, should be exercised in administering the 10 percent solutions to children of low body weight, the elderly, and patients with insulin-dependent diabetes, hypertension, hyperthyroidism, generalized arteriosclerosis, or cardiovascular disease. The posttreatment blood pressure of these patients, and any patients who develop symptoms, should be carefully monitored.
Ordinarily, any mydriatic, including NEO-SYNEPHRINE hydrochloride, solution, is contraindicated in patients with glaucoma, since it may occasionally raise intraocular pressure. However, when temporary dilatation of the pupil may free adhesions or when vasoconstriction of intrinsic vessels may lower intraocular tension, these advantages may temporarily outweigh the danger from coincident dilatation of the pupil.
Rebound miosis has been reported in older persons one day after receiving NEO-SYNEPHRINE hydrochloride ophthalmic solutions, and reinstillation of the drug produced a reduction in mydriasis. This may be of clinical importance in dilating the pupils of older subjects prior to retinal detachment or cataract surgery.
Due to a strong action of the drug on the dilator muscle, older individuals may also develop transient pigment floaters in the aqueous humor 30 to 45 minutes following the administration of NEO-SYNEPHRINE hydrochloride ophthalmic solutions. The appearance may be similar to anterior uveitis or to a microscopic hyphema.
To prevent pain, a drop of suitable topical anesthetic may be applied before using the 10 percent ophthalmic solution.
Drug Interaction: As with all other adrenergic drugs, when NEO-SYNEPHRINE 10 percent ophthalmic solutions or 2.5 percent ophthalmic solution is administered simultaneously with, or up to 21 days after, administration of monoamine oxidase (MAO) inhibitors, careful supervision and adjustment of dosages are required since exaggerated adrenergic effects may occur. The pressor response of adrenergic agents may also be potentiated by tricyclic antidepressants, propranolol, reserpine, guanethidine, methyldopa, and atropine-like drugs.
It has been reported that the concomitant use of NEO-SYNEPHRINE 10 percent ophthalmic solutions and systemic beta blockers has caused acute hypertension and, in one case, the rupture of a congenital cerebral aneurysm. NEO-SYNEPHRINE may potentiate the cardiovascular depressant effects of potent inhalation anesthetic agents.
Carcinogenesis, Mutagenesis, Impairment of Fertility: No long-term animal studies have been done to evaluate the potential of NEO-SYNEPHRINE in these areas.
Pregnancy Category C: Animal reproduction studies have not been conducted with NEO-SYNEPHRINE. It is also not known whether NEO-SYNEPHRINE can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. NEO-SYNEPHRINE should be given to a pregnant woman only if clearly needed.
Nursing Mothers: It is not known whether this drug is excreted in milk; many are. Caution should be exercised when NEO-SYNEPHRINE hydrochloride ophthalmic solution is administered to a nursing woman.
Pediatric Use: NEO-SYNEPHRINE hydrochloride 10 percent ophthalmic solutions are contraindicated in infants. (See CONTRAINDICATIONS .) For use in older children see DOSAGE AND ADMINISTRATION .
Exceeding recommended dosages or applying NEO-SYNEPHRINE hydrochloride ophthalmic solutions to the instrumented, traumatized, diseased or postsurgical eye or adnexa, or to patients with suppressed lacrimation, as during anesthesia, may result in the absorption of sufficient quantities of phenylephrine to produce a systemic vasopressor response.
The hypertensive effects of phenylephrine may be treated with an alpha-adrenergic blocking agent such as phentolamine mesylate, 5 mg to 10 mg intravenously, repeated as necessary.
The oral LD 50 of phenylephrine in the rat: 350 mg/kg, in the mouse: 120 mg/kg.
Prolonged exposure to air or strong light may cause oxidation and discoloration. Do not use if solution is brown or contains a precipitate.
NEO-SYNEPHRINE hydrochloride 10 percent ophthalmic solutions are especially useful when rapid and powerful dilatation of the pupil and reduction of congestion in the capillary bed are desired. A drop of a suitable topical anesthetic may be applied, followed in a few minutes by 1 drop of the NEO-SYNEPHRINE hydrochloride 10 percent ophthalmic solutions on the upper limbus. The anesthetic prevents stinging and consequent dilution of the solution by lacrimation. It may occasionally be necessary to repeat the instillation after one hour, again preceded by the use of the topical anesthetic.
NEO-SYNEPHRINE hydrochloride 10 percent ophthalmic solutions may be used in patients with uveitis when synechiae are present or may develop. The formation of synechiae may be prevented by the use of the 10 percent ophthalmic solutions and atropine to produce wide dilatation of the pupil. It should be emphasized, however, that the vasoconstrictor effect of NEO-SYNEPHRINE hydrochloride may be antagonistic to the increase of local blood flow in uveal infection.
To free recently formed posterior synechiae, 1 drop of the 10 percent ophthalmic solutions may be applied to the upper surface of the cornea. On the following day, treatment may be continued if necessary. In the interim, hot compresses should be applied for five or ten minutes three times a day, with 1 drop of a 1 or 2 percent solution of atropine sulfate before and after each series of compresses.
In certain patients with glaucoma, temporary reduction of intraocular tension may be attained by producing vasoconstriction of the intraocular vessels; this may be accomplished by placing 1 drop of the 10 percent ophthalmic solutions on the upper surface of the cornea. This treatment may be repeated as often as necessary.
NEO-SYNEPHRINE hydrochloride, may be used with miotics in patients with wide angle glaucoma. It reduces the difficulties experienced by the patient because of the small field produced by miosis, and still it permits and often supports the effect of the miotic in lowering the intraocular pressure. Hence, there may be marked improvement in visual acuity after using NEO-SYNEPHRINE hydrochloride in conjunction with miotic drugs.
When a short-acting mydriatic is needed for wide dilatation of the pupil before intraocular surgery, the 10 percent ophthalmic solutions or 2.5 percent ophthalmic solution may be applied topically from 30 to 60 minutes before the operation.
Prior to determination of refractive errors, NEO-SYNEPHRINE hydrochloride 2.5 percent ophthalmic solution may be used effectively with homatropine hydrobromide, atropine sulfate, or a combination of homatropine and cocaine hydrochloride.
For adults, a drop of the preferred cycloplegic is placed in each eye, followed in five minutes by 1 drop of NEO-SYNEPHRINE hydrochloride 2.5 percent ophthalmic solution and in ten minutes by another drop of the cycloplegic. In 50 to 60 minutes, the eyes are ready for refraction.
For children, a drop of atropine sulfate 1 percent is placed in each eye, followed in 10 to 15 minutes by 1 drop of NEO-SYNEPHRINE hydrochloride 2.5 percent ophthalmic solution and in five to ten minutes by a second drop of atropine sulfate 1 percent. In one to two hours, the eyes are ready for refraction.
For a "one application method," NEO-SYNEPHRINE hydrochloride 2.5 percent ophthalmic solution may be combined with a cycloplegic to elicit synergistic action. The additive effect varies depending on the patient. Therefore, when using a ``one application method," it may be desirable to increase the concentration of the cycloplegic.
One drop of NEO-SYNEPHRINE hydrochloride 2.5 percent ophthalmic solution is placed in each eye. Sufficient mydriasis to permit examination is produced in 15 to 30 minutes. Dilatation lasts from one to three hours.
Provocative Test for Angle Block in Patients with Glaucoma: The 2.5 percent ophthalmic solution may be used as a provocative test when latent increased intraocular pressure is suspected. Tension is measured before application of NEO-SYNEPHRINE hydrochloride and again after dilatation. A 3 to 5 mm of mercury rise in pressure suggests the presence of angle block in patients with glaucoma; however, failure to obtain such a rise does not preclude the presence of glaucoma from other causes.
Shadow Test (Retinoscopy): When dilatation of the pupil without cycloplegic action is desired for the shadow test, the 2.5 percent ophthalmic solution may be used alone.
Blanching Test: One or 2 drops of the 2.5 percent ophthalmic solution should be applied to the injected eye. After five minutes, examine for perilimbal blanching. If blanching occurs, the congestion is superficial and probably does not indicate iritis.
In Mono-Drop ® (plastic dropper) bottle:
2.5 percent ophthalmic solution --
NEO-SYNEPHRINE hydrochloride, 2.5 percent in a sterile, isotonic, buffered, low surface tension vehicle with sodium phosphate, sodium biphosphate, boric acid, and, as antiseptic preservative, benzalkonium chloride, NF, 1:7500. The pH is adjusted with phosphoric acid or sodium hydroxide.
Bottles of 15 mL (NDC 0024-1358-01)
10 percent ophthalmic solution --
NEO-SYNEPHRINE hydrochloride 10 percent in a sterile, buffered, low surface tension vehicle with sodium phosphate, sodium biphosphate, and, as antiseptic preservative, benzalkonium chloride 1:10,000. The pH is adjusted with phosphoric acid or sodium hydroxide.
Bottles of 5 mL (NDC 0024-1359-01)
10 percent ophthalmic solution --
NEO-SYNEPHRINE hydrochloride 10 percent in a sterile, buffered, viscous vehicle with sodium phosphate, sodium biphosphate, methylcellulose, and, as antiseptic preservative, benzalkonium chloride 1:10,000. The pH is adjusted with phosphoric acid or sodium hydroxide.
Bottles of 5 mL (NDC 0024-1362-01)
Store at 25°C (77°F); excursions permitted to 15°C-30°C (59°F-86°F) [see USP Controlled Room Temperature]
Revised September 1999
NSW-5-E