Histinex HC

Medical Editor: John P. Cunha, DO, FACOEP Last updated on RxList: 8/9/2022

Drug Summary

What Is Histinex HC?

Histinex HC (phenylephrine, hydrocodone, chlorpheniramine) is a combination of an antihistamine, a nasal decongestant, and a cough syrup prescribed to relieve the symptoms of cough, nasal congestion, and discomfort associated with upper respiratory tract infections. Histinex HC may no longer be available in the U.S. Generic forms may be available.

What Are Side Effects of Histinex HC?

Common side effects of Histinex HC (phenylephrine, hydrocodone, chlorpheniramine) include:

  • allergic reactions such as rash,
  • urinary frequency or difficulty urinating,
  • high or low blood pressure,
  • ringing in the ears,
  • faintness,
  • giddiness,
  • dry mouth and nose,
  • drowsiness,
  • headache,
  • dizziness,
  • blurred vision,
  • nausea,
  • vomiting,
  • heart palpitations,
  • ringing in the ears,
  • loss of coordination,
  • vision problems,
  • irritability,
  • excitement,
  • weight loss,
  • diarrhea, or
  • constipation

Histinex HC may cause serious side effects including:

  • hives,
  • difficulty breathing,
  • swelling of your face, lips, tongue, or throat,
  • breathing that slows or stops,
  • shallow breathing with long pauses,
  • blue colored lips,
  • difficult to wake up,
  • noisy breathing,
  • sighing,
  • slow heart rate,
  • weak pulse,
  • nervousness,
  • trouble sleeping,
  • severe constipation, and
  • little or no urination

Get medical help right away, if you have any of the symptoms listed above.

Seek medical care or call 911 at once if you have the following serious side effects:

  • Serious eye symptoms such as sudden vision loss, blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights;
  • Serious heart symptoms such as fast, irregular, or pounding heartbeats; fluttering in your chest; shortness of breath; and sudden dizziness, lightheartedness, or passing out;
  • Severe headache, confusion, slurred speech, arm or leg weakness, trouble walking, loss of coordination, feeling unsteady, very stiff muscles, high fever, profuse sweating, or tremors.

This document does not contain all possible side effects and others may occur. Check with your physician for additional information about side effects.

Dosage for Histinex HC

The recommended dosage of Histinex HC is 2 teaspoons every 4 hours.

What Drugs, Substances, or Supplements Interact with Histinex HC?

Histinex HC may interact with other drugs. Tell your doctor all medications you take. Do not drive, use machinery, or do any activity that requires alertness when taking Histinex HC.

Histinex HC During Pregnancy or Breastfeeding

If you are pregnant only take Histinex HC if clearly needed. It is not known if Histinex HC is excreted in breast milk. Consult your doctor if you are breastfeeding.

Additional Information

Our Histinex HC (phenylephrine, hydrocodone, chlorpheniramine) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

Drug Description


Histinex® HC (phenylephrine, hydrocodone, cpm) is a clear, orange-colored, sugar free, alcohol free syrup with characteristic fruity odor for oral administration.

Each teaspoonful (5 mL) contains:

Hydrocodone Bitartrate* ............................................2.5 mg
Phenylephrine Hydrochloride ......................................5.0 mg
Chlorpheniramine Maleate ........................................2.0 mg

Antitussive/nasal decongestant/antihistamine syrup for oral administration.

Also contains citric acid, FD&C Yellow No. 6 (Sunset Yellow), flavorings, glycerin, hydrochloric acid, maltitol solution, propylene glycol, purified water, saccharin sodium, sodium benzoate, sodium hydroxide, sodium phosphate dibasic and sorbitol solution.

*(Warning: May be habit forming)

Indications & Dosage


Histinex® HC (phenylephrine, hydrocodone, cpm) is indicated for the symptomatic relief of cough, nasal congestion and discomfort associated with upper respiratory tract infections.


Adults and pediatric patients over 12 years - 2 teaspoonsful (10 mL) every 4 hours, not to exceed 8 teaspoonsful in 24 hours. Pediatric patients 6 to 12 years - 1 teaspoonful (5 mL) every 4 hours, not to exceed 4 teaspoonsful in 24 hours. Pediatric patients under 6 years - use only as directed by a physician.


Bottles of 16 fl. oz. (473 mL) NDC 58177-877-07

Bottles of 32 fl. oz. (946 mL) NDC 58177-877-12


Store at controlled room temperature, 59°-86°F (15°-30°C)

Dispense in tight, child resistant, light-resistant containers as defined by the USP/NF.

Manufactured by: KV Pharmaceutical Co. for ETHEX Corporation St. Louis, MO 63043-2413. Rev. 10/98.

Side Effects & Drug Interactions


Adverse reactions to Histinex® HC (phenylephrine, hydrocodone, cpm) may include hypersensitivity reactions such as rash, urticaria, leukopenia, agranulocytosis and thrombocytopenia, drowsiness, lassitude, giddiness, dryness of the mucous membranes, tightness of the chest, thickening of bronchial secretions, urinary frequency and dysuria, palpitation, hypertension/hypotension, headache, faintness, dizziness, tinnitus, incoordination, visual disturbances, mydriasis, CNS depressant and (less often) stimulant effect, increased irritability or excitement, anorexia, nausea, vomiting, diarrhea, constipation and epigastric distress.

Drug Abuse And Dependence

This product is a Schedule III Controlled Substance. Because of the hydrocodone content, some abuse might be expected. Psychic dependence, physical dependence and tolerance may deveolop upon repeated administration. It should be prescribed and administered with the degree of caution appropriate for this type product.


No information provided.

Warnings & Precautions


No information provided.


Administer with care in patients with cardiac or peripheral vascular diseases or hypertension. Until the patient's response has been determined, he should be cautioned against engaging in operations which require alertness, such as driving an automobile, operating machinery, etc. Patients receiving antihistamines should be warned against possible additive effects with CNS depressants such as alcohol, hypnotics, sedatives, tranquilizers, etc. Since hydrocodone may produce drowsiness, persons who perform hazardous tasks requiring mental alertness or physical coordination should be cautioned accordingly.

Carcinogenesis, Mutagenesis, Impairment of Fertility

Carcinogenicity, mutagenicity, and reproduction studies have not been conducted with Histinex® HC (phenylephrine, hydrocodone, cpm) Syrup.


Teratogenic Effects. Pregnancy category C. Animal reproduction studies have not been conducted with Histinex® HC (phenylephrine, hydrocodone, cpm) Syrup. It is also not known whether Histinex® HC (phenylephrine, hydrocodone, cpm) Syrup can cause fetal harm when administered to a pregnant woman or can affect reproductive capacity. Histinex® HC (phenylephrine, hydrocodone, cpm) Syrup should be given to a pregnant woman only if clearly needed.

Nursing mothers

It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk and because of the potential for serious adverse reactions in nursing infants from Histinex® HC (phenylephrine, hydrocodone, cpm) Syrup, a decision should be made whether to discontinue nursing or discontinue the drug, taking into the account the importance of the drug to the mother.

Pediatric Use

Safety and effectiveness in pediatric patients below the age of 6 has not been established.

Geriatric Use

Clinical studies of Histinex® HC (phenylephrine, hydrocodone, cpm) syrup did not include sufficient numbers of subjects aged 65 and over to determine whetherthey respond differently from younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy.

Sedating drugs may cause confusion and over-sedation in the elderly; elderly patients generally should be started on low doses of Histinex® HC (phenylephrine, hydrocodone, cpm) syrup and observed closely.

Overdose & Contraindications


No information provided.


Hypersensitivity to antihistamines of the same chemical class. Histinex® HC is contraindicated during pregnancy and in concurrent therapy with MAO inhibitors. Because of its drying effect on lower respiratory secretions, Histinex® HC is not recommended in the treatment of bronchial asthma.

Clinical Pharmacology


Histinex® HC (phenylephrine, hydrocodone, cpm) reduces excessive nasal secretions, diminishes edema of the nasal mucosa and congestion of the upper respiratory tract and abolishes or diminishes cough. The antihistaminic action of chlorpheniramine maleate reduces or abolishes allergenic responses of nasal tissue. Its action is complemented by the mild vasoconstrictor action of phenylephrine hydrochloride which provides a nasal decongestant effect. Cough suppression is a result of the action of hydrocodone bitartrate.

Medication Guide


No information provided. Please refer to the WARNINGS and PRECAUTIONS sections.

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