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Sildec PE DM Syrup

Generic name: chlorpheniramine maleate, phenylephrine hydrochloride and dextromethorphan
Dosage form: syrup
Drug class: Upper respiratory combinations

Medically reviewed by Last updated on April 21, 2021.

Disclaimer: This drug has not been found by FDA to be safe and effective, and this labeling has not been approved by FDA. For further information about unapproved drugs, click here.

Sildec PE DM Syrup Description

CPM/PE/DM Syrup is a sugar-free, alcohol-free, grape flavored syrup for oral administration for adults and for pediatric patients 2 years and older.

Each teaspoonful (5 mL) contains:
Chlorpheniramine maleate ………………. 4.0 mg
Phenylephrine hydrochloride ……………. 12.5 mg
Dextromethorphan hydrobromide ……….. 15.0 mg

Inactive ingredients: Citric acid, D&C Red No. 33, FD&C Blue No. 1, flavor, glycerin, purified water, sodium benzoate, sodium saccharin, and sorbitol. May contain sodium citrate.

Chlorpheniramine maleate is an antihistamine with the chemical name: 2-Pyridinepropanamine, y-(4-chlorophenyl)-N, N-dimethyl-, (Z)-2-butenedioate (1:1). Its chemical structure is as follows:

Phenylephrine hydrochloride is a mydriatic and a decongestant with the chemical name: (-)-m-Hydroxy-α-[(methylamino)methyl]benzyl alcohol hydrochloride. Its chemical structure is as follows:

Dextromethorphan hydrobromide is an antitussive with the chemical name 3-Methoxy-17-methyl-9α, 13α, 14α - morphinan hydrobromide monohydrate. Its structure is as follows:

Sildec PE DM Syrup - Clinical Pharmacology

Antihistaminic, decongestant and antitussive actions.

Chlorpheniramine maleate possesses H1 antihistaminic activity and mild anticholinergic and sedative effects. Peak plasma concentration is reached in 5 hours. Urinary excretion is the major route of elimination. The liver is assumed to be the major site of metabolic transformation.

Phenylephrine hydrochloride is an oral sympathomimetic amine that acts as a decongestant to respiratory tract mucous membranes. While its vasoconstrictor action is similar to that of ephedrine, phenylephrine has less pressor effect in normotensive adults. Serum half-life for phenylephrine is 6 to 8 hours. Acidic urine is associated with faster elimination of the drug. About one-half of the administered dose is excreted in the urine.

Dextromethorphan hydrobromide is a non-narcotic antitussive with effectiveness equal to codeine. It acts in the medulla oblongata to elevate the cough threshold. Dextromethorphan does not produce analgesia or induce tolerance, and has no potential for addiction. At usual doses, it will not depress respiration or inhibit ciliary activity. Dextromethorphan is rapidly metabolized with trace amounts of the parent compound in blood and urine. About one-half of the administered dose is excreted in the urine as conjugated metabolites.

Indications and Usage for Sildec PE DM Syrup

For relief of coughs and upper respiratory symptoms, including nasal congestion, associated with allergy or the common cold.


Patients with hypersensitivity or idiosyncrasy to any of its ingredients.

Sympathomimetic amines are contraindicated in patients with severe hypertension, severe coronary artery disease and patients on monoamine oxidase (MAO) inhibitor therapy. Antihistamines are contraindicated in patients with narrow angle glaucoma, urinary retention, peptic ulcer and during an asthma attack. Dextromethorphan should not be used in patients receiving a monoamine oxidase inhibitor (MAOI) or for 2 weeks after stopping the MAOI drug.


Do not exceed recommended dosage.

Sympathomimetic amines should be used judiciously and sparingly in patients with hypertension, diabetes, ischemic heart disease, hyperthyroidism, increased intraocular pressure or prostatic hypertrophy (See CONTRAINDICATIONS). Sympathomimetic amines may produce CNS stimulation with convulsions or cardiovascular collapse with accompanying hypotension. The elderly (60 years and older) are more likely to exhibit adverse reactions. Antihistamines may cause excitability, especially in children. At doses higher than the recommended dose, nervousness, dizziness or sleeplessness may occur. Administration of dextromethorphan may be accompanied by histamine
release and should be used with caution in atopic children.


General: Before prescribing medication to suppress or modify cough, identify and provide therapy for the underlying cause of the cough and take caution that modification of cough does not increase the risk of clinical or physiologic complications. Dextromethorphan should be used with caution in sedated or debilitated patients and in patients confined to supine positions. Use with caution in patients with hypertension, heart disease, asthma, hyperthyroidism, increased intraocular pressure, diabetes mellitus and prostatic hypertrophy.

Information for Patients: Avoid alcohol and other CNS depressants while taking this product. Patients sensitive to antihistamines may experience moderate to severe drowsiness. Patients sensitive to sympathomimetic amines may notice mild CNS stimulation. Antihistamines may impair mental and physical abilities required for the performance of potentially hazardous tasks such as driving a vehicle or operating machinery. Patients should be warned accordingly.

Drug Interactions: Antihistamines may enhance the effects of tricyclic antidepressants, barbiturates, alcohol and other CNS depressants. MAO inhibitors prolong and intensify the anticholinergic effects of antihistamines. Sympathomimetic amines may reduce the antihypertensive effects of reserpine, veratrum alkaloids, methyldopa and mecamylamines. Effects of sympathomimetics are increased with MAO inhibitors and beta-adrenergic blockers. The cough-suppressant action of dextromethorphan and narcotic antitussives are additive. Dextromethorphan is contraindicated with monoamine oxidase inhibitors (MAOI). (See CONTRAINDICATIONS section.)

Use in Pregnancy: Pregnancy Category C. Animal reproduction studies have not been conducted with CPM/PE/DM Syrup. It is not known whether these products can cause fetal harm when administered to a pregnant woman or affect reproduction capacity. Give to a pregnant woman only if clearly needed.

Nursing Mothers: It is not known whether the drugs in CPM/PE/DM Syrup are excreted in human milk. Since many drugs are excreted in human milk and because of the potential for serious side effects in nursing infants, a decision should be made whether to discontinue nursing or discontinue the use of these products, taking into account the importance of the drug to the mother.

Adverse Reactions

Antihistamines may cause sedation, dizziness, diplopia, vomiting, diarrhea, dry mouth, headache, nervousness, nausea, anorexia, heartburn, weakness, polyuria and dysuria and, rarely, excitability in children. Urinary retention may occur in patients with prostatic hypertrophy. Sympathomimetic amines may cause convulsions, CNS stimulation, cardiac arrhythmia, respiratory difficulties, increased heart rate or blood pressure, hallucinations, tremors, nervousness, insomnia, pallor and dysuria. Dextromethorphan may cause drowsiness, dizziness and GI disturbance.


No information is available as to specific results of an overdose of CPM/PE/DM Syrup. The signs, symptoms and treatments described below are those of H1 antihistamine, ephedrine, and dextromethorphan overdose.

Symptoms: Should antihistamine effects predominate, central action constitutes the greatest danger. In the small child, predominant symptoms are excitation, hallucination, ataxia, incoordination, tremors, flushed face and fever. Convulsions, fixed and dilated pupils, coma and death may occur in severe cases. In the adult, fever and flushing are uncommon; excitement leading to convulsions and postictal depression is often preceded by drowsiness and coma. Respiration is usually not seriously depressed; blood pressure is usually stable.

Should sympathomimetic symptoms predominate, central effects include restlessness, dizziness, tremor, hyperactive reflexes, talkativeness, irritability and insomnia. Cardiovascular and renal effects include difficulty in micturition, headache, flushing, palpitation, cardiac arrhythmia, hypertension with subsequent hypotension and circulatory collapse. Gastrointestinal effects include dry mouth, metallic taste, anorexia, nausea, vomiting, diarrhea and abdominal cramps.

Dextromethorphan may cause respiratory depression with a large overdose.

Treatment: (a) Evacuate stomach as condition warrants. Activated charcoal may be useful. (b) Maintain a nonstimulating environment. (c) Monitor cardiovascular status. (d) Do not give stimulants. (e) Reduce fever with cool sponging. (f) Treat respiratory depression with naloxone if dextromethorphan toxicity is suspected. (g) Use sedatives or anticonvulsants to control CNS excitation and convulsions. (h) Physostigmine may reverse anticholinergic symptoms. (i) Ammonium chloride may acidify the urine to increase urinary excretion of phenylephrine. (j) Further care is symptomatic and supportive.

Sildec PE DM Syrup Dosage and Administration

CHLORPHENIRAMINE / PHENYLEPHRINE/ DEXTROMETHORPHAN Syrup (CPM/PE/DM Syrup) Adults and Children 12 years of age and older: 1 teaspoonful (5 mL) every 4 to 6 hours, not to exceed 6 teaspoonfuls in 24 hours. Children 6 to under 12 years of age: 1/2 teaspoonful (2.5 mL) every 4 to 6 hours, not to exceed 3 teaspoonfuls in 24 hours. Children 2 to under 6 years of age: 1/4 teaspoonful (1.25 mL) every 4 to 6 hours, not to exceed 1.5 teaspoonfuls in 24 hours. Not recommended for use in children under 2 years of age.

In mild cases or in particularly sensitive patients, less frequent or reduced doses may be appropriate and adequate.

How is Sildec PE DM Syrup Supplied

CHLORPHENIRAMINE / PHENYLEPHRINE/ DEXTROMETHORPHAN Syrup (CPM/PE/DM Syrup) CPM/PE/DM Syrup is sugar-free, alcohol-free, and grape flavored. It is available in bottles of 16 fluid ounce (473 mL) bottles and 4 fluid ounce (118 mL).

Dispense in a tight, light-resistant container as defined in USP with a child resistant closure.


Store at Controlled Room Temperature between 20°-25°C (68°-77°F); excursions permitted to 15°- 30°C (59°-86°F) [See USP Controlled Room Temperature]. Avoid exposure to heat. Keep tightly closed.

KEEP THIS AND ALL DRUGS OUT OF THE REACH OF CHILDREN. In case of accidental overdose, seek professional assistance or contact a Poison Control Center immediately.

Manufactured by:
Silarx Pharmaceuticals, Inc.
Spring Valley, NY 10977

Sildec PE DM Syrup
Sildec PE DM Syrup syrup
Product Information
Product Type HUMAN PRESCRIPTION DRUG LABEL Item Code (Source) NDC:54838-544
Route of Administration ORAL DEA Schedule
Active Ingredient/Active Moiety
Ingredient Name Basis of Strength Strength
Chlorpheniramine maleate (Chlorpheniramine) Chlorpheniramine maleate 4 mg in 5 mL
Phenylephrine hydrochloride (Phenylephrine) Phenylephrine hydrochloride 12.5 mg in 5 mL
Dextromethorphan hydrobromide (Dextromethorphan) Dextromethorphan hydrobromide 15 mg in 5 mL
Inactive Ingredients
Ingredient Name Strength
anhydrous citric acid
D&C Red No. 33
FD&C Blue No. 1
sodium benzoate
saccharin sodium
sodium citrate
Product Characteristics
Color Score
Shape Size
Flavor GRAPE (grape flavor) Imprint Code
# Item Code Package Description
1 NDC:54838-544-80 473 mL in 1 BOTTLE, PLASTIC
Marketing Information
Marketing Category Application Number or Monograph Citation Marketing Start Date Marketing End Date
unapproved other 01/05/2006
Labeler - Silarx Pharmaceuticals, Inc (161630033)
Silarx Pharmaceuticals, Inc

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