What is C-Phen DM (Chlorpheniramine/Dextromethorp/Phenylephrine)?

Chlorpheniramine is an antihistamine that reduces the natural chemical histamine in the body. Histamine can produce symptoms of sneezing, itching, watery eyes, and runny nose.

Dextromethorphan is a cough suppressant. It affects the signals in the brain that trigger cough reflex.

Phenylephrine is a decongestant that shrinks blood vessels in the nasal passages. Dilated blood vessels can cause nasal congestion (stuffy nose).

Chlorpheniramine, dextromethorphan, and phenylephrine is used to treat sneezing, cough, runny or stuffy nose, itchy or watery eyes, hives, skin rash, itching, and other symptoms of allergies and the common cold.

Dextromethorphan will not treat a cough that is caused by smoking, asthma, or emphysema.

Chlorpheniramine, dextromethorphan, and phenylephrine may also be used for other purposes not listed in this medication guide.

What is the most important information I should know about C-Phen DM (Chlorpheniramine/Dextromethorp/Phenylephrine)?

Always ask a doctor before giving a cough or cold medicine to a child. Death can occur from the misuse of cough and cold medicines in very young children.

Do not use a cough or cold medicine if you have used an MAO inhibitor such as isocarboxazid (Marplan), phenelzine (Nardil), rasagiline (Azilect), selegiline (Eldepryl, Emsam), or tranylcypromine (Parnate) within the past 14 days. Serious, life-threatening side effects can occur if you take cough or cold medicine before the MAO inhibitor has cleared from your body.

Do not use any other over-the-counter cough, cold, allergy, or sleep medication without first asking your doctor or pharmacist. If you take certain products together you may accidentally take too much of one or more types of medicine. Read the label of any other medicine you are using to see if it contains an antihistamine, decongestant, or cough suppressant.

Chlorpheniramine, dextromethorphan, and phenylephrine can cause side effects that may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be awake and alert.

Avoid drinking alcohol. It can increase some of the side effects of this medication.

What should I discuss with my healthcare provider before taking C-Phen DM (Chlorpheniramine/Dextromethorp/Phenylephrine)?

Before taking this medication, tell your doctor if you are allergic to chlorpheniramine, dextromethorphan, or phenylephrine, or if you have:

kidney disease
liver disease
diabetes
glaucoma
heart disease or high blood pressure
diabetes
a thyroid disorder
a stomach ulcer or a stomach obstruction,
emphysema or chronic bronchitis; or
an enlarged prostate or urination problems

If you have any of these conditions, you may need a dose adjustment or special tests to safely take this medication.

FDA pregnancy category C. This medication may be harmful to an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant during treatment.

Chlorpheniramine, dextromethorphan, and phenylephrine can pass into breast milk and may harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby.

Artificially-sweetened liquid forms of cough-and-cold medications may contain phenylalanine. This would be important to know if you have phenylketonuria (PKU). Check the ingredients and warnings on the medication label if you are concerned about phenylalanine.

C-Phen DM Side Effects

What are the possible side effects of C-Phen DM (Chlorpheniramine/Dextromethorp/Phenylephrine)?

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Stop using this medication and call your doctor at once if you have any of these serious side effects:

fast, pounding, or uneven heartbeat
confusion, hallucinations, unusual thoughts or behavior
severe dizziness, anxiety, restless feeling, or nervousness
increased blood pressure (severe headache, blurred vision, trouble concentrating, chest pain, numbness, seizure)
confusion, hallucinations
slow, shallow breathing
urinating less than usual or not at all
easy bruising or bleeding, unusual weakness, fever, chills, body aches, flu symptoms; or
nausea, stomach pain, low fever, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes)

Less serious side effects may include:

blurred vision
dry mouth
nausea, stomach pain, constipation
mild loss of appetite, stomach upset
warmth, tingling, or redness under your skin
feeling excited or restless
sleep problems (insomnia)
restless or excitability (especially in children)
skin rash or itching
dizziness, drowsiness
problems with memory or concentration; or
ringing in your ears

This is not a complete list of side effects and others may occur. Tell your doctor about any unusual or bothersome side effect. You may report side effects to FDA at 1-800-FDA-1088.

C-Phen DM Interactions

What other drugs affect C-Phen DM (Chlorpheniramine/Dextromethorp/Phenylephrine)?

Before taking this medication, tell your doctor if you are using any of the following drugs:

an antidepressant
a diuretic (water pill)
medication to treat irritable bowel syndrome
celecoxib (Celebrex)
cinacalcet (Sensipar)
imatinib (Gleevec)
quinidine (Quinaglute, Quinidex)
ranolazine (Ranexa)
ritonavir (Norvir)
sibutramine (Meridia)
terbinafine (Lamisil)
medicines to treat high blood pressure
aspirin or salicylates (such as Disalcid, Doan’s Pills, Dolobid, Salflex, Tricosal, and others)
bladder or urinary medications such as darifenacin (Enablex), oxybutynin (Ditropan, Oxytrol) or tolterodine (Detrol); or
a beta-blocker such as atenolol (Tenormin), carteolol (Cartrol), metoprolol (Lopressor, Toprol), nadolol (Corgard), propranolol (Inderal), sotalol (Betapace), timolol (Blocadren), and others

This list is not complete and there may be other drugs that can interact with chlorpheniramine, dextromethorphan, and phenylephrine. Tell your doctor about all the prescription and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor.

What should I avoid while taking C-Phen DM (Chlorpheniramine/Dextromethorp/Phenylephrine)?

This medication can cause side effects that may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be awake and alert.

Avoid drinking alcohol. It can increase some of the side effects of this medication.

Before taking this medication, tell your doctor if you regularly use other medicines that make you sleepy (such as cold or allergy medicine, narcotic pain medicine, sleeping pills, muscle relaxers, and medicine for seizures, depression, or anxiety). They can add to sleepiness caused by this medication.

Avoid taking diet pills, caffeine pills, or other stimulants (such as ADHD medications) without your doctor’s advice. Taking a stimulant together with a decongestant can increase your risk of unpleasant side effects.

Do not use any other over-the-counter cough, cold, allergy, or sleep medication without first asking your doctor or pharmacist. Antihistamines, decongestants, and cough suppressants are contained in many medicines available over the counter. If you take certain products together you may accidentally take too much of one or more types of medicine. Read the label of any other medicine you are using to see if it contains an antihistamine, decongestant, or cough suppressant.

C-Phen DM Dosage

How should I take C-Phen DM (Chlorpheniramine/Dextromethorp/Phenylephrine)?

Use this medication exactly as directed on the label or as it was prescribed for you. Do not take the medication in larger amounts, or take it for longer than recommended by your doctor.

Always ask a doctor before giving a cough or cold medicine to a child. Death can occur from the misuse of cough and cold medicines in very young children.

Take this medicine with a full glass of water. If you use the effervescent tablet, drop the tablet in 8 ounces of water and allow it to dissolve completely. Stir this mixture and drink all of it right away. To make sure you get the entire dose, add a little more water to the same glass, swirl gently and drink right away.

Measure the liquid form of this medicine with a special dose-measuring spoon or cup, not a regular table spoon. If you do not have a dose-measuring device, ask your pharmacist where you can get one.

Take this medicine with food or milk if it upsets your stomach.

This medication can cause you to have unusual results with allergy skin tests. Tell any doctor who treats you that you are taking an antihistamine.

Talk with your doctor if your symptoms do not improve after 7 days of treatment, or if you have a fever with a headache, cough, or skin rash.

If you need to have any type of surgery, tell the surgeon ahead of time if you have taken a cold medicine within the past few days.

Store the medication at room temperature away from moisture and heat.

What happens if I overdose on C-Phen DM (Chlorpheniramine/Dextromethorp/Phenylephrine)?

Seek emergency medical attention if you think you have used too much of this medicine.

Overdose symptoms may include feeling restless or nervous, nausea, vomiting, stomach pain, dizziness, drowsiness, dry mouth, warmth or tingly feeling, or seizure (convulsions).

What happens if I miss a dose of C-Phen DM (Chlorpheniramine/Dextromethorp/Phenylephrine)?

Since cough or cold medicine is usually taken only as needed, you may not be on a dosing schedule. If you are taking the medication regularly, take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and take the medicine at your next regularly scheduled time. Do not take extra medicine to make up the missed dose.

Edited from everydayhealth.com

C-Phen DM (Chlorpheniramine/Dextromethorp/Phenylephrine)