What is C Phen (Chlorpheniramine 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.
Phenylephrine is a decongestant that shrinks blood vessels in the nasal passages. Dilated blood vessels can cause nasal congestion (stuffy nose).
The combination of chlorpheniramine and phenylephrine is used to treat symptoms of the common cold or seasonal allergies, including sneezing, runny or stuffy nose, and itchy, watery eyes.
Chlorpheniramine 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 (Chlorpheniramine Phenylephrine)?
There are many brands and forms of this medication available and not all brands are listed on this leaflet.
Do not use chlorpheniramine and phenylephrine 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. Dangerous side effects may occur if you take chlorpheniramine and phenylephrine before the MAO inhibitor has cleared from your body.
Do not use this medication if you are allergic to chlorpheniramine or phenylephrine, or if you have severe high blood pressure or coronary artery disease, narrow-angle glaucoma, a stomach ulcer, or if you are unable to urinate.
Do not use this medication during an asthma attack.
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 chlorpheniramine and phenylephrine.
Older adults may be more likely to have side effects from this medicine.
Do not give this medication to a child younger than 2 years old. 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.
Contact your doctor if your symptoms do not improve or if they get worse after taking this medicine for 7 days.
What should I discuss with my healthcare provider before taking C Phen (Chlorpheniramine Phenylephrine)?
Do not use chlorpheniramine and phenylephrine 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. Dangerous side effects may occur if you take chlorpheniramine and phenylephrine before the MAO inhibitor has cleared from your body.
Do not use this medication if you are allergic to chlorpheniramine or phenylephrine, or if you have:
- severe or uncontrolled high blood pressure
- severe coronary artery disease
- narrow angle glaucoma
- a stomach ulcer; or
- if you are unable to urinate
Do not use this medication during an asthma attack.
Ask a doctor or pharmacist if it is safe for you to take this medication if you have:
- kidney disease
- liver disease
- diabetes
- glaucoma
- circulation problems
- heart disease or high blood pressure
- overactive thyroid
- a seizure disorder such as epilepsy
- asthma, emphysema or chronic bronchitis; or
- urination problems or an enlarged prostate
FDA pregnancy category C. It is not known whether chlorpheniramine and phenylephrine is harmful to an unborn baby. Before taking this medication, tell your doctor if you are pregnant or plan to become pregnant during treatment.
It is not known whether chlorpheniramine and phenylephrine passes into breast milk or if it could harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby.
Older adults may be more likely to have side effects from this medicine.
C Phen Side Effects
What are the possible side effects of C Phen (Chlorpheniramine 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 chlorpheniramine and phenylephrine and call your doctor at once if you have any of these serious side effects:
- fast or uneven heart beats
- feeling light-headed, fainting
- seizure (convulsions)
- hallucinations (seeing things that are not there); or
- tremors
Less serious side effects may include:
- heartburn, nausea, vomiting, diarrhea, loss of appetite
- dry nose or mouth
- drowsiness, dizziness, weakness, headache
- dry eyes, blurred vision
- painful or difficult urination
- sleep problems (insomnia)
- feeling nervous or excited (especially in children)
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
C Phen Interactions
What other drugs affect C Phen (Chlorpheniramine Phenylephrine)?
Sedatives, narcotic pain medicine, sleeping pills, muscle relaxers, and medicine for seizures, depression or anxiety can add to sleepiness caused by chlorpheniramine. Tell your doctor if you regularly use any of these medicines, or any other cold or allergy medications..
Tell your doctor about all other medications you use, especially:
- mecamylamine (Inversine)
- methyldopa (Aldomet)
- reserpine
- a beta-blocker such as atenolol (Tenormin, Tenoretic), carvedilol (Coreg), labetalol (Normodyne, Trandate), metoprolol (Lopressor, Toprol), nadolol (Corgard), propranolol (Inderal, InnoPran), sotalol (Betapace), and others
- a barbiturate such as amobarbital (Amytal), butabarbital (Butisol), mephobarbital (Mebaral), secobarbital (Seconal), or phenobarbital (Luminal, Solfoton); or
- an antidepressant such as amitriptyline (Elavil, Vanatrip), doxepin (Sinequan), desipramine (Norpramin), imipramine (Janimine, Tofranil), nortriptyline (Pamelor), and others
This list is not complete and there may be other drugs that can interact with chlorpheniramine 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 (Chlorpheniramine 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 chlorpheniramine and phenylephrine.
Avoid using other medicines that may cause restlessness (such as caffeine, stimulants, diet pills, and decongestants contained in over-the-counter cold medicines). They can add to the stimulant effects of phenylephrine.
C Phen Dosage
How should I take C Phen (Chlorpheniramine Phenylephrine)?
Use this medication as directed on the label, or as your doctor has prescribed. Do not use the medication in larger amounts or for longer than recommended.
Do not give this medication to a child younger than 2 years old. 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.
Do not crush, chew, break, or open an extended-release tablet or capsule. Swallow the pill whole. It is specially made to release medicine slowly in the body. Breaking or opening the pill would cause too much of the drug to be released at one time.
The chewable tablet must be chewed before swallowing.
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.
Contact your doctor if your symptoms do not improve or if they get worse after taking this medicine for 7 days.
Store chlorpheniramine and phenylephrine at room temperature away from moisture and heat.
What happens if I overdose on C Phen (Chlorpheniramine Phenylephrine)?
Seek emergency medical attention if you think you have used too much of this medicine.
Overdose can cause nausea, vomiting, diarrhea, stomach pain, problems with balance or coordination, headache, urination problems, dizziness, feeling excited or irritable, hallucinations (seeing things), metallic taste in your mouth, tremors, fever, flushed face, and seizure (convulsions).
What happens if I miss a dose of C Phen (Chlorpheniramine Phenylephrine)?
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 the next regularly scheduled time. Do not take extra medicine to make up the missed dose.
Edited from everydayhealth.com