Chlorpheniramine, Phenylephrine, and Methscopolamine



AH-Chew®[DSC]; AH-Chew II; Chlor-Mes-D; Dallergy®; Dehistine; Drize®-R; Extendryl; Extendryl JR; Extendryl SR; Hista-Vent® DA; PCM; PCM Allergy







Chlorpheniramine, Phenylephrine, and Methscopolamine

(klor fen IR a meen, fen il EF rin, & meth skoe POL a meen)

U.S. Brand Names
AH-Chew®[DSC]; AH-Chew II; Chlor-Mes-D; Dallergy®; Dehistine; Drize®-R; Extendryl; Extendryl JR; Extendryl SR; Hista-Vent® DA; PCM; PCM Allergy
Pharmacologic Category
Antihistamine/Decongestant/Anticholinergic
Reasons not to take this medicine
  • If you have an allergy to chlorpheniramine, phenylephrine, methscopolamine, or any other part of this medicine.
  • Tell healthcare provider if you are allergic to any medicine. Make sure to tell about the allergy and how it affected you. This includes telling about rash; hives; itching; shortness of breath; wheezing; cough; swelling of face, lips, tongue, or throat; or any other symptoms involved.
  • If you have any of the following conditions: Asthma, glaucoma, heart disease, high blood pressure, overactive thyroid gland, trouble urinating, or ulcers in your stomach or intestines.
  • If you have taken isocarboxazid, phenelzine, or tranylcypromine in the last 14 days. Monoamine oxidase inhibitors (eg, isocarboxazid, phenelzine, and tranylcypromine) must be stopped 14 days before this medicine is started. Taking the two together could cause dangerously high blood pressure.
What is this medicine used for?
  • This medicine is used to treat nasal congestion.
How does it work?
  • Chlorpheniramine blocks the allergic reaction by minimizing or preventing the body's reaction to the allergen.
  • Phenylephrine shrinks swollen nasal tissue and opens up passages.
  • Methscopolamine treats nasal congestion.
How is it best taken?
  • Take this medicine with or without food. Take with food if it causes an upset stomach.
  • Long-acting products: Swallow whole. Do not chew, break, or crush.
  • A liquid (syrup) is available if you cannot swallow pills.
  • Those who have feeding tubes can also use the liquid. Flush the feeding tube before and after medicine is given.
What do I do if I miss a dose? (does not apply to patients in the hospital)
  • Take a missed dose as soon as possible.
  • If it is almost time for the next dose, skip the missed dose and return to your regular schedule.
  • Do not take a double dose or extra doses.
  • Many times this medicine is taken on an as needed basis.
What are the precautions when taking this medicine?
  • If you are 65 or older, use this medicine with caution. You could have more side effects.
  • If you have diabetes, talk with healthcare provider.
  • Check medicines with healthcare provider. This medicine may not mix well with other medicines.
  • If you have PKU, talk with healthcare provider. Some products do contain phenylalanine.
  • You may not be alert. Avoid driving, doing other tasks or activities until you see how this medicine affects you.
  • Avoid alcohol (includes wine, beer, and liquor) or other medicines and natural products that slow your actions and reactions. These include sedatives, tranquilizers, mood stabilizers, antihistamines, and other pain medicine.
  • Limit caffeine (for example, tea, coffee, cola) and chocolate intake. Use with this medicine may cause nervousness, shakiness, and fast heartbeat.
  • Tell healthcare provider if you are pregnant or plan on getting pregnant.
  • Tell healthcare provider if you are breast-feeding.
What are some possible side effects of this medicine?
  • Feeling lightheaded, sleepy, having blurred vision, or a change in thinking clearly. Avoid driving, doing other tasks or activities that require you to be alert or have clear vision until you see how this medicine affects you.
  • Dry mouth. Frequent mouth care, sucking hard, sugar-free candy, or chewing sugar-free gum may help.
  • Inability to sleep.
What should I monitor?
  • Change in condition being treated. Is it better, worse, or about the same?
  • Dry mouth may cause an increase in cavities. Take good care of your teeth. See a dentist regularly.
Reasons to call healthcare provider immediately
  • If you suspect an overdose, call your local poison control center immediately or dial 911.
  • Signs of a life-threatening reaction. These include wheezing; chest tightness; fever; itching; bad cough; blue skin color; fits; or swelling of face, lips, tongue, or throat.
  • Chest pain or pressure or fast heartbeat.
  • Severe dizziness or passing out.
  • Very nervous and excitable.
  • Severe headache.
  • Unable to pass urine.
  • Feeling extremely tired or weak.
  • Sudden change in vision, eye pain or irritation.
  • Any rash.
  • No improvement in condition or feeling worse.
How should I store this medicine?
  • Store at room temperature.
  • Protect capsules and tablets from moisture. Do not store in a bathroom or kitchen.
General statements
  • If you have a life-threatening allergy, wear allergy identification at all times.
  • Do not share your medicine with others and do not take anyone else's medicine.
  • Keep all medicine out of the reach of children and pets.
  • Keep a list of all your medicines (prescription, natural products, supplements, vitamins, over-the-counter) with you. Give this list to healthcare provider (doctor, nurse, nurse practitioner, pharmacist, physician assistant).
  • Talk with healthcare provider before starting any new medicine, including over-the-counter, natural products, or vitamins.
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