What is Mytussin AC (Codeine Guaifenesin)?

Codeine is in a group of drugs called narcotics. It is a cough suppressant that affects the signals in the brain that trigger cough reflex.
Guaifenesin is an expectorant. It helps loosen mucus congestion in your chest and throat, making it easier to cough out through your mouth.
The combination of codeine and guaifenesin is used to treat cough and to reduce chest congestion caused by upper respiratory infections or the common cold.
Codeine and guaifenesin will not treat a cough that is caused by smoking, asthma, or emphysema.
Codeine and guaifenesin may also be used for other purposes not listed in this medication guide.

What is the most important information I should know about Mytussin AC (Codeine Guaifenesin)?

Do not use any other over-the-counter cough or cold 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 guaifenesin.
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.
Codeine may be habit-forming and should be used only by the person it was prescribed for. This medication should never be shared with another person, especially someone who has a history of drug abuse or addiction. Keep the medication in a secure place where others cannot get to it.
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.

What should I discuss with my healthcare provider before taking Mytussin AC (Codeine Guaifenesin)?

You should not take this medication if you are allergic to codeine or guaifenesin.
If you have any of these other conditions, you may need a dose adjustment or special tests to safely take codeine and guaifenesin:

• heart disease, heart rhythm disorder
• asthma, COPD, emphysema, or other breathing disorders
• a history of head injury or brain tumor
• epilepsy or other seizure disorder
• a stomach or intestinal disorder
• Addison’s disease or other adrenal gland disorders
• curvature of the spine
• a thyroid disorder
• liver or kidney disease
• enlarged prostate; or
• a history of depression, mental illness, or drug addiction

FDA pregnancy category C. This medication may be harmful to an unborn baby, and could cause addiction or withdrawal symptoms in a newborn. Tell your doctor if you are pregnant or plan to become pregnant during treatment.
Codeine can pass into breast milk and may harm a nursing baby. The use of codeine by some nursing mothers may lead to life-threatening side effects in the baby. Do not use this medication if you are breast-feeding a baby.
Codeine may be habit-forming and should be used only by the person it was prescribed for. Codeine should never be shared with another person, especially someone who has a history of drug abuse or addiction. Keep the medication in a secure place where others cannot get to it.
Older adults may be more likely to have side effects from this medication.
Liquid forms of this medication may contain sugar or artificial sweetener (phenylalanine). Talk to your doctor before using this form of codeine and guaifenesin if you have diabetes or phenylketonuria (PKU).

Mytussin AC Side Effects

What are the possible side effects of Mytussin AC (Codeine Guaifenesin)?

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

• severe dizziness or drowsiness
• confusion, hallucinations, unusual thoughts or behavior
• urinating less than usual or not at all; or
• slow heart rate, weak pulse, fainting, weak or shallow breathing

Less serious side effects include:

• dizziness, drowsiness, headache
• warmth, redness, or tingling under your skin
• nausea, vomiting, upset stomach
• constipation; or
• skin rash or itching

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.

Mytussin AC Interactions

What other drugs affect Mytussin AC (Codeine Guaifenesin)?

Before taking this medication, tell your doctor if you regularly use other medicines that make you sleepy (such as allergy medicine, narcotic pain medicine, sleeping pills, muscle relaxers, and medicine for seizures, depression, or anxiety). They can add to sleepiness caused by codeine and guaifenesin.
Also tell your doctor if you are using any of the following drugs:

• cimetidine (Tagamet)
• quinidine (Quinaglute, Quinidex, Quin-Release)
• naloxone (Narcan); or
• naltrexone (Vivitrol)

This list is not complete and there may be other drugs that can interact with codeine and guaifenesin. 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 Mytussin AC (Codeine Guaifenesin)?

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.
Do not use any other over-the-counter cough or cold medication without first asking your doctor or pharmacist. Guaifenesin is contained in many medicines available over the counter. If you take certain products together you may accidentally take too much of a certain drug. Read the label of any other medicine you are using to see if it contains guaifenesin.
Avoid drinking alcohol. It can increase some of the side effects of this medication.

Mytussin AC Dosage

How should I take Mytussin AC (Codeine Guaifenesin)?

Take this medication exactly as it has been prescribed by your doctor. Do not use the medication in larger amounts, or use it for longer than recommended. Follow the directions on your prescription label. Cough or cold medicine is usually taken only for a short time until your symptoms clear up.
Always ask a doctor before giving cough or cold medicine to a child. Death can occur from the misuse of cough or cold medicine in very young children.
Take codeine and guaifenesin with food if it upsets your stomach.
Drink extra fluids to help loosen the congestion and lubricate your throat while you are taking this medication.
Measure liquid 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 for one.
Call your doctor if your symptoms do not improve after 7 days of treatment, or if you also have a fever, headache, or skin rash.
This medication can cause you to have unusual results with certain medical tests. Tell any doctor who treats you that you are using codeine and guaifenesin.
Do not stop using this medication suddenly after long-term use or you could have unpleasant withdrawal symptoms. Talk to your doctor about how to avoid withdrawal symptoms when stopping the medication.
Store codeine and guaifenesin at room temperature away from moisture, heat, and light. Keep the bottle tightly closed when not in use.
Keep track of how much of this medicine has been used from each new bottle. Codeine is a drug of abuse and you should be aware if any person in the household is using this medicine improperly or without a prescription.

What happens if I overdose on Mytussin AC (Codeine Guaifenesin)?

Seek emergency medical attention if you think you have used too much of this medicine. An overdose of codeine can be fatal.
Overdose symptoms may include extreme dizziness or drowsiness, nausea, vomiting, sweating, confusion, hallucinations, cold and clammy skin, blue-colored lips or fingernails, weak or limp muscles, pinpoint pupils, weak pulse, slow breathing, fainting, or seizures (convulsions).

What happens if I miss a dose of Mytussin AC (Codeine Guaifenesin)?

Since cough 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