What does Guaiatussin AC have in it?

Guaiatussin AC is an over-the-counter cough medicine that contains two active ingredients: guaifenesin and codeine. Guaifenesin helps thin mucus in the airways, making coughs more productive. Codeine acts as a cough suppressant by reducing activity in the brain’s cough center. In addition to the active ingredients, Guaiatussin AC contains several inactive ingredients that give the medication its flavor, color, and consistency. This article will provide a comprehensive overview of all the ingredients found in Guaiatussin AC.

Active Ingredients


Guaifenesin is an expectorant that helps loosen mucus in the airways. It allows people to cough up phlegm more easily, helping relieve congestion from colds, flu, and acute bronchitis. Guaifenesin works by drawing water into the bronchial passages through osmosis. This thins the mucus, making it less sticky and easier to cough up. Most cough medicines contain 100-200 mg of guaifenesin per dose. The extended-release version found in Guaiatussin AC provides cough relief for up to 12 hours. Some key facts about guaifenesin:

– Derived from the Guaiac tree native to the Caribbean and Central/South America

– Classified as an expectorant since the 1950s

– Considered safe and effective by the FDA

– Recommended for adults and children over 2 years old

– May cause drowsiness or dizziness in some individuals

– Those with kidney stones should use caution when taking guaifenesin


Codeine is an opioid that suppresses the cough reflex in the brain. It binds to opioid receptors, which inhibit activity in the medulla oblongata, the part of the brain that controls coughing. This provides temporary relief from dry, irritating coughs caused by conditions like upper respiratory infections and bronchitis. Guaiatussin AC contains 10 mg of codeine per 5 mL dose. Key facts about codeine:

– Derived from the opium poppy like morphine and heroin

– Classified as a narcotic antitussive or cough suppressant

– Requires a prescription in higher doses due to addiction risk

– Not recommended for chronic coughs, only short-term symptom relief

– Causes drowsiness, dizziness, nausea and constipation as side effects

– High doses can slow or stop breathing, requiring emergency intervention

– Not safe for children under 18 years or adults over 65 years old

Inactive Ingredients

In addition to guaifenesin and codeine, Guaiatussin AC contains several inactive ingredients that add flavor, color, and texture while ensuring the medication is stable and effective. Inactive ingredients include:


Sorbitol is a sugar alcohol that acts as a sweetener and thickening agent. Since guaifenesin has a bitter taste, sorbitol improves the flavor. Sorbitol also gives syrups a viscous, syrup-like consistency. In cough medicines, it creates a soothing, coating sensation in the throat. Sorbitol occurs naturally in fruits and plants like apples, peaches, and seaweed. Key facts:

– Classified as a polyol sweetener and sugar substitute

– About 60% as sweet as sucrose but with fewer calories

– Does not promote tooth decay like sucrose and other sugars

– Has a laxative effect in large doses

– Well-tolerated by most people unless fructose intolerant

Sodium benzoate

Sodium benzoate acts as a preservative in Guaiatussin AC. It prevents the growth of bacteria, yeast, and mold that could contaminate the medication. Sodium benzoate extends the shelf life of syrups and liquids. It works optimally in acidic conditions below pH 5. Common in acidic foods like vinegar, apple cider, and soft drinks. Key facts:

– Approved preservative by the FDA and WHO

– Found naturally in cranberries, cloves, cinnamon and other foods

– GRAS (Generally Recognized as Safe) by the FDA

– Non-toxic in small doses; may cause DNA damage in large quantities

– Potential allergen; reactions are rare

D&C Red #33

D&C Red #33 provides the vibrant red color in Guaiatussin AC. Also known as Food Red #3, this synthetic dye intensifies the look of medicines and foods. It adds visual appeal to make the syrup more appetizing. Key facts:

– Approved by the FDA for use in foods, drugs and cosmetics

– Deemed safe based on animal testing data

– Allergic reactions very rare; may cause hives, asthma or anaphylaxis in sensitive individuals

– Banned in some European countries like Norway and Austria

– Does not cause cancer based on current research

Purified water

Purified water acts as the base for Guaiatussin AC’s liquid form. It dissolves the active and inactive ingredients to create a homogeneous solution. Purified water must meet United States Pharmacopeia (USP) standards for pharmaceutical use. It is free of microbes, toxins, and other harmful contaminants. The syrup base consists of approximately 80% purified water.


Guaiatussin AC contains 5% alcohol by volume. The alcohol helps dissolve and blend the ingredients into a uniform syrup. It provides solvent properties that improve the bioavailability of the active compounds. Alcohol adds a pleasant taste and mouthfeel as well. The low concentration is not enough to cause impairment or interact with the codeine.

Medicinal Benefits

The ingredients in Guaiatussin AC provide the following medicinal benefits for treating cough symptoms:

Relieves chest congestion

The guaifenesin thins and loosens mucus, allowing for more productive coughs that clear phlegm from the airways. This relieves congestion and pressure in the chest caused by mucus buildup.

Soothes sore throat

The syrup base and alcohol create a soothing coating over the throat. This provides temporary pain relief for soreness caused by coughing and postnasal drip.

Temporarily suppresses cough

The codeine binds to receptors in the brain, reducing the urge to cough. This allows for 4-6 hours of cough suppression.

Helps regain sleep

By relieving congestion and coughing, Guaiatussin AC improves sleep in those with disruptive nighttime cough symptoms. The drowsiness from codeine also aids with sleep.

Safe when used as directed

The FDA has approved Guaiatussin AC as safe and effective when used according to label directions. The ingredients have GRAS status and a long history of use in other cough medicines.

Safety Profile

When taken as directed on the label, Guaiatussin AC has a good safety profile with minimal side effects. However, the following precautions are important to note:

– Not safe for children under 4 years old due to risk of slowed breathing.

– Should not exceed recommended doses due to overdose risk. An overdose can be fatal.

– Codeine has greater effects in those who metabolize it rapidly (ultrarapid metabolizers) increasing overdose risk. Genetic testing can identify if someone is an ultrarapid metabolizer.

– May cause severe allergic reactions in those with sensitivities to codeine, guaifenesin or inactive ingredients. Discontinue use if hives, swelling or anaphylaxis occurs.

– Those with kidney disorders, head injuries or breathing issues should not use Guaiatussin AC.

– Codeine is habit-forming. Do not use for more than 1 week to avoid dependence.

– Alcohol and sedatives increase the drowsiness and respiratory effects. Avoid other CNS depressants.

When used carefully per label instructions, Guaiatussin AC is generally safe for temporary relief of cough symptoms in appropriate populations. But side effects are possible even at regular doses. Seek medical care if you experience worrisome reactions. Never take more than the recommended amount and do not use longer than directed.

Potential Side Effects

The following side effects may occur when taking Guaiatussin AC:


The codeine can cause sedation as it suppresses the cough reflex. This often improves rest and sleep but may also impair mental alertness and motor coordination. Use caution when driving or operating machinery.


Some individuals may feel lightheaded or dizzy after taking a dose. Move carefully until you know how Guaiatussin AC affects your body.


Stomach upset and nausea are possible, especially when taking the first few doses. Take with food to reduce chances of nausea.


The codeine has a binding effect on the digestive tract, often causing constipation. Stay hydrated and consume fiber to prevent constipation symptoms.

Dry mouth

Antihistamine effects can reduce saliva production, leading to temporary dry mouth. Drink lots of water while on the medication.


Headaches have been reported but are uncommon. Discontinue use if severe headaches develop.


In rare cases, Guaiatussin AC may cause abnormal heart rhythms from electrolyte disturbances. Seek immediate care if palpitations or irregular heartbeats occur.

Allergic reaction

Seek emergency care for swelling of the tongue, lips or face along with difficulty breathing. These signify a dangerous allergic reaction.

While most side effects are mild, pay attention to your body’s response. Report any unusual symptoms to your doctor promptly. Never exceed the prescribed dose.


The codeine in Guaiatussin AC can interact with numerous medications and substances. Potential interactions include:


Enhances the sedative and respiratory effects of the codeine, increasing the risk of dangerous central nervous system and breathing depression. Avoid alcohol.


Xanax, Valium, Ativan and other benzodiazepines also depress the CNS. Concurrent use can lead to impaired thinking, slowed heart rate and respiration, coma or death. Use extreme caution.

Muscle relaxants

Soma, Flexeril and other muscle relaxants have additive effects with codeine, severely depressing the CNS and respiratory system. Do not combine these medications with Guaiatussin AC.

Illicit drugs

Heroin, morphine, methadone and other illicit opiates taken with codeine greatly increase the chance of overdose and death. Illicit drug use while taking Guaiatussin AC can have fatal results.

MAO inhibitors

Antidepressants like Nardil and Parnate prevent the metabolism of codeine, causing its accumulation to toxic levels. Allow 14 days before taking Guaiatussin AC after stopping an MAO inhibitor.

Macrolide antibiotics

Medications like Zithromax and erythromycin block the metabolism of codeine, raising its levels. Use an alternative antibiotic or avoid Guaiatussin AC.


Grapefruit inhibits the CYP3A4 enzyme that metabolizes codeine, increasing its effects. Avoid grapefruit juice when using Guaiatussin AC.

Consult your pharmacist about any other medications you take to identify potential interactions with codeine. Never take any other medicine that contains codeine or other narcotic cough suppressants when taking Guaiatussin AC.

Dosing Instructions

Follow these dosing instructions carefully when taking Guaiatussin AC:

– Take only as directed on the label.

– Carefully measure each dose using the measuring cup or syringe provided. Never exceed the prescribed amount.

– Usual dose is 5mL every 4 to 6 hours as needed. Do not take more than 6 doses (30mL) per 24 hours.

– Only use for a maximum of 1 week to avoid dependence.

– Shake well before each dose.

– For children ages 4-12, consult pediatrician for proper dosing based on weight and age. Not recommended under age 4.

– For adults over 65, maximum dose is 5mL every 12 hours.

– If cough persists for more than 1 week, contact your doctor. Do not exceed recommended time period of use.

Take precautions when measuring and administering Guaiatussin AC to avoid accidental overdose. Never combine with other codeine medications or alcohol. Seek medical advice if cough lasts beyond 1 week of treatment.

When to Seek Medical Care

Contact your doctor promptly if you experience:

– Cough lasting more than 1 week during Guaiatussin AC treatment

– Cough that produces green, yellow or bloody mucus

– High fever above 101 F

– Shortness of breath or difficulty breathing

– Wheezing, chest tightness

– Fast, irregular heart rate

– Severe dizziness, fainting

– Confusion, hallucinations

– Severe constipation for more than 3 days

– Hives, swelling, severe allergic reaction

– Seizures

These may indicate a serious medical issue that requires further evaluation and treatment beyond Guaiatussin AC. The medication only temporarily relieves symptoms and does not treat underlying conditions. Seek immediate help if you have an allergic reaction, overdose, or difficulty breathing.


Guaiatussin AC carries the following warnings:

– Not for use in children under age 4

– Avoid alcohol during use

– May cause drowsiness; use caution when driving

– Do not exceed recommended doses

– Avoid stopping suddenly after prolonged use

– Contains codeine, may be habit-forming

– Keep out of reach of children and pets

– Do not use if you have severe kidney, lung, heart or intestinal issues

– Allergic reactions may occur in those sensitive to ingredients

Use care when taking Guaiatussin AC to reduce adverse events. Discontinue use if unusual symptoms develop. This medication may have potential for abuse and should be taken only as directed for cough relief. Consult your doctor for warnings related to your specific medical conditions.


In summary, Guaiatussin AC is a combination cough syrup containing the expectorant guaifenesin and the cough suppressant codeine. It provides temporary relief for cough symptoms by thinning mucus and blocking cough receptors in the brain. The medication also contains sweeteners, preservatives, and dyes as inactive ingredients. When taken as directed on the label, Guaiatussin AC can safely and effectively help manage coughs caused by colds, flu and acute bronchitis. But side effects are possible even at regular doses. To avoid dangerous interactions and adverse events, take precautions and follow dosing instructions carefully. Only use for short-term cough relief and consult a doctor if your cough persists longer than 1 week or worrisome symptoms develop.

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