United States - English - NLM (National Library of Medicine)
METAPROTERENOL SULFATE- metaproterenol sulfate syrup
Lannett Company, Inc.
Metaproterenol Sulfate Syrup, USP
Metaproterenol sulfate syrup is an oral bronchodilator.
Each teaspoonful (5 mL), for oral administration, contains metaproterenol sulfate 10 mg. In addition,
each teaspoonful (5 mL) contains the following inactive ingredients:
citric acid, edetate disodium, FD&C Red No. 40, glycerin, hydroxyethyl cellulose, black cherry flavor,
propylene glycol, saccharin sodium, sodium benzoate, sorbitol solution, sodium citrate and purified
Metaproterenol sulfate, 1- (3, 5 dihydroxyphenyl) -2-isopropyl - aminoethanol sulfate, is a white,
crystalline, racemic mixture of two optically active isomers. It has the following structural formula:
In vitro studies and in vivo pharmacologic studies have demonstrated that metaproterenol sulfate has a
preferential effect on beta adrenergic receptors compared with isoproterenol. While it is recognized
that beta adrenergic receptors are the predominant receptors in bronchial smooth muscle, recent data
indicate that there is a population of beta receptors in the human heart existing in a concentration
between 10 to 50%. The precise function of these, however, is not yet established (see WARNINGS
The pharmacologic effects of beta adrenergic agonist drugs, including metaproterenol, are at least in
part attributable to stimulation through beta adrenergic receptors of intracellular adenyl cyclase, the
enzyme which catalyzes the conversion of adenosine triphosphate (ATP) to cyclic-3’, 5’ -adenosine
monophosphate (c-AMP). Increased c-AMP levels are associated with relaxation of bronchial smooth
muscle and inhibition of release of mediators of immediate hypersensitivity from cells, especially from
PHARMACOKINETICS: Absorption, biotransformation and excretion studies in humans following
oral administration have indicated that an average of less than 10% of the drug is absorbed intact; it is
not metabolized by catechol-0-methyltransferase nor converted to glucuronide conjugates but is
excreted primarily as the sulfate conjugate formed in the gut.
Pulmonary function tests performed after the administration of metaproterenol usually show
improvement, e.g., an increase in the one-second forced expiratory volume (FEV ), maximum expiratory
flow rate, peak expiratory flow rate, forced vital capacity, and/or a decrease in airway resistance. The
resultant decrease in airway obstruction may relieve the dyspnea associated with bronchospasm.
Pulmonary function has been monitored in controlled single- and multiple-dose studies. The duration of
effect of a single dose of metaproterenol sulfate syrup (that is, the period of time during which there is
a 15% or greater increase in mean FEV ) was up to 4 hours. Recent studies in laboratory animals
(minipigs, rodents and dogs) recorded the occurrence of cardiac arrhythmias and sudden death (with
histologic evidence of myocardial necrosis) when beta agonists and methylxanthines were administered
concurrently. The significance of these findings when applied to humans is currently unknown.
INDICATIONS AND USAGE
Metaproterenol sulfate syrup is indicated as a bronchodilator for bronchial asthma and for reversible
bronchospasm which may occur in association with bronchitis and emphysema.
Use in patients with cardiac arrhythmias associated with tachycardia is contraindicated.
Although rare, immediate hypersensitivity reactions can occur. Therefore, metaproterenol sulfate syrup
is contraindicated in patients with a history of hypersensitivity to any of its components.
Metaproterenol, like other beta adrenergic agonists, can produce a significant cardiovascular effect in
some patients, as measured by pulse rate, blood pressure, symptoms, and/or ECG changes.
General: Extreme care must be exercised with respect to the administration of additional
Since metaproterenol is a sympathomimetic amine, it should be used with caution in patients with
cardiovascular disorders, including ischemic heart disease, hypertension or cardiac arrhythmias, in
patients with hyperthyroidism or diabetes mellitus, and in patients who are unusually responsive to
sympathomimetic amines or who have convulsive disorders. Significant changes in systolic and
diastolic blood pressure could be expected to occur in some patients after use of any beta adrenergic
Information For Patients: Appropriate care should be exercised when considering the administration
of additional sympathomimetic agents. A sufficient interval of time should elapse prior to administration
of another sympathomimetic agent. Metaproterenol should not be used more often than prescribed. If
symptoms persist, patients should consult a physician promptly.
Drug Interactions: Other beta adrenergic bronchodilators should not be used concomitantly with
metaproterenol because they may have additive effects. Beta adrenergic agonist should be administered
with caution to patients being treated with monoamine oxidase inhibitors or tricyclic antidepressants,
since the action of beta adrenergic agonists on the vascular system may be potentiated.
Pregnancy: Teratogenic Effects: PREGNANCY CATEGORY C: Metaproterenol sulfate has been
shown to be teratogenic and embryotoxic in rabbits when given in doses corresponding to 62 times the
maximum recommended dose. These effects included skeletal abnormalities, hydrocephalus and skull
bone separation. Results of other studies in rabbits, rats or mice have not revealed any teratogenic,
embryotoxic or fetotoxic effects. There are no adequate and well-controlled studies in pregnant
women. Metaproterenol sulfate should be used during pregnancy only if the potential benefit justifies
the potential risk to the fetus.
Nursing Mothers: It is not known whether metaproterenol is excreted in human milk; therefore,
metaproterenol should be used during nursing only if the potential benefit justifies the possible risk to
Pediatric Use: Safety and effectiveness in children below the age of 6 have been demonstrated in a
limited number of patients. See DOSAGE AND ADMINISTRATION section.
Adverse reactions are similar to those noted with other sympathomimetic agents.
The following table of adverse experiences is derived from 44 clinical trials involving 1,120 patients
treated with metaproterenol sulfate syrup:
Metaproterenol Sulfate Syrup Incidence of Adverse
Events Occurring in at least 1% of Patients
Number of Patients %
Central Nervous System
The expected symptoms with overdosage are those of excessive beta stimulation and/or any of the
symptoms listed under ADVERSE REACTIONS, e.g., angina, hypertension or hypotension.
arrhythmias, nervousness, headache, tremor, dry mouth, palpitation, nausea, dizziness, fatigue, malaise
The treatment consists of discontinuation of metaproterenol together with appropriate symptomatic
DOSAGE AND ADMINISTRATION
Metaproterenol sulfate syrup contains 10 mg of metaproterenol sulfate per teaspoonful (5 mL).
Children: Aged six to nine years or weight under 60 lb - one teaspoonful (5 mL) three or four times a
day. Children over nine years or weight over 60 lb - two teaspoonfuls (10 mL) three or four times a
day. Clinical trial experience in children under the age of six is limited. Of 40 children treated with
metaproterenol sulfate syrup for at least one month, daily doses of approximately 1.3 to 2.6 mg/kg were
Adults: Two teaspoonfuls (10 mL) three or four times a day.
It is recommended that the physician titrate the dosage according to each individual patient’s response to
Metaproterenol Sulfate Syrup, USP is available as a red, cherry-flavored syrup containing 10 mg of
metaproterenol sulfate per teaspoonful (5 mL) in 473 mL (one pint) bottles.
Store below 86°F (30°C). Protect from light.
Silarx Pharmaceuticals, Inc.
1033 Stoneleigh Ave
Carmel, NY 10512
metaproterenol sulfate syrup
Product T ype
HUMAN PRESCRIPTION DRUG
Ite m Code (Source )
NDC:548 38 -50 7
Lannett Company, Inc.
Route of Administration
Active Ingredient/Active Moiety
Basis of Strength
Stre ng th
METAPRO TERENO L SULFATE (UNII: GJ20 H50 YF0 ) (METAPROTERENOL -
UNII:53QOG56 9 E0 )
in 5 mL
Stre ng th
ANHYDRO US CITRIC ACID (UNII: XF417D3PSL)
EDETATE DISO DIUM (UNII: 7FLD9 1C8 6 K)
GLYCERIN (UNII: PDC6 A3C0 OX)
HYDRO XYETHYL CELLULO SE ( 2 0 0 0 CPS AT 1%) (UNII: S38 J6 RZN16 )
PRO PYLENE GLYCO L (UNII: 6 DC9 Q16 7V3)
SACCHARIN SO DIUM (UNII: SB8 ZUX40 TY)
SO DIUM BENZO ATE (UNII: OJ245FE5EU)
SO RBITO L (UNII: 50 6 T6 0 A25R)
SO DIUM CITRATE (UNII: 1Q73Q2JULR)
WATER (UNII: 0 59 QF0 KO0 R)
FD&C RED NO . 4 0 (UNII: WZB9 127XOA)
S hap e
S iz e
CHERRY (Black Cherry)
NDC:548 38 -50 7-
473 mL in 1 BOTTLE, PLASTIC; Type 0 : No t a Co mbinatio n
Pro duc t
0 9 /0 8 /20 0 9
Marke ting Cate gory
Application Numbe r or Monograph Citation
Marke ting Start Date
Marke ting End Date
ANDA0 736 32
0 9 /0 8 /20 0 9
Lannett Company, Inc. (161630033)