Deconex IR is a combination medication that contains guaifenesin (an expectorant) and phenylephrine (a decongestant). It's used to temporarily relieve cold and allergy symptoms, such as stuffy nose and chest congestion, in people ages 6 years and older. This medication is taken by mouth, typically every 4 hours. But it's not recommended for people who are pregnant. Side effects aren't common, but can include dizziness and headache.
Short-term relief of runny or stuffy nose due to allergies or the common cold
Loosens mucus to ease chest congestion
Sinus congestion and pressure
Deconex IR (guaifenesin / phenylephrine) is a combination of two medications that work together to relieve symptoms associated with a cough, allergies, and the common cold.
Guaifenesin is an expectorant. It thins and loosens mucus that's stuck in your airways, making it easier to cough it up.
Phenylephrine is a decongestant, which works to relieve stuffy nose. It tightens the blood vessels around your nose, which eases nasal swelling and pressure. This allows you to breathe easier and to have better sinus drainage.
Source:Â DailyMed
Side effects that you should report to your care team as soon as possible:
Side effects that usually do not require medical attention (report these to your care team if they continue or are bothersome):
Combines two medications into a single tablet
Available over the counter
Taken by mouth
Phenylephrine doesn't typically work well for treating congestion
Not be appropriate for children younger than 6 years old (check label of individual product)
Might not be a good option while pregnant or breastfeeding
Check the Deconex IR (guaifenesin / phenylephrine) label carefully for specific directions. There are many different formulations of guaifenesin/phenylephrine products. They might have different directions or contain different dosages of the individual active ingredients. Ask your pharmacist if you have any questions about your product.
You might feel nervous or have trouble sleeping after you take Deconex IR (guaifenesin / phenylephrine). These can be side effects of the phenylephrine in the medication. If this happens, try to avoid taking the medication close to bedtime. Contact your primary care provider if that doesn't help.
Let your primary care provider know if you have a cough that's caused by cigarette smoke, a cough that's linked to a breathing problem (e.g., asthma, emphysema), or a cough with a lot of mucus. Deconex IR (guaifenesin / phenylephrine) might not be appropriate for you in these cases and you might need a different treatment option.
Stop taking Deconex IR (guaifenesin / phenylephrine) and contact your primary care provider if your cough or stuffy nose lasts more than a week or comes back after clearing up. Also tell them if you have a rash, fever, or headache along with your cough or stuffy nose. These might be symptoms of a more serious condition and you might need more medical attention.
Don't start any new medications while you're taking Deconex IR (guaifenesin / phenylephrine) — especially other guaifenesin or decongestant products — without talking to your primary care provider or pharmacist first. Taking certain medications with Deconex IR (guaifenesin / phenylephrine) can raise your risk for serious side effects, including high blood pressure, fast heart rate, or possibly hallucinations (seeing or hearing things that aren't real).
Deconex IR (guaifenesin / phenylephrine) shouldn't be taken with a monoamine oxidase inhibitor (MAOI), such as selegiline, phenelzine (Nardil), or tranylcypromine (Parnate). This combination can raise your risk for severe side effects (e.g., high blood pressure, dizziness). If you're currently taking an MAOI or have taken one in the last 2 weeks, don't take Deconex IR (guaifenesin / phenylephrine) and contact your provider for other options to treat your symptoms.
Store Deconex IR (guaifenesin / phenylephrine) up and away and out of children's reach and sight. This prevents them from accidentally swallowing any medication that was left out. Call a Poison Center at 1-800-222-1222 right away if you think that your child accidentally swallowed Deconex IR (guaifenesin / phenylephrine).
Deconex IR (guaifenesin / phenylephrine) can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
Risk factors: Taking with other similar medications
Gilphex contains an expectorant (guaifenesin) and a decongestant (phenylephrine). These ingredients can be found in many other over-the-counter products.
Using more than one product containing the same (or similar) ingredients as Deconex IR (guaifenesin / phenylephrine) raises the risk that you might accidentally take too much of a particular ingredient. This can be harmful. For example, taking too much phenylephrine can cause anxiety, ringing in the ears, and blurry vision.
Ask your primary care provider or pharmacist if you're not sure whether you're taking a medication with any of the ingredients in Deconex IR (guaifenesin / phenylephrine). Carefully read and follow the product instructions on the package. Call a Poison Center at 1-800-222-1222 right away if you think that you or your child accidentally took too much medication (even if you aren't completely sure).
Risk factors: Long-term cough or cough with too much mucus | Cough from smoking, asthma, chronic bronchitis, or emphysema | Heart disease or high blood pressure | Thyroid problems | High blood sugar (diabetes) | Urinary conditions
Tell your primary care provider (PCP) about all your medical conditions that you have before you start Deconex IR (guaifenesin / phenylephrine). It's possible for this medication to worsen your medical condition(s) and cause serious side effects. Or the medication might not be appropriate for you based on your medical condition(s). Your PCP can check that Deconex IR (guaifenesin / phenylephrine) is appropriate and safe for you to take.
Dosage | Quantity | Price as low as | Price per unit |
---|---|---|---|
385mg/10mg | 30 tablets | $23.48 | $0.78 |
Each tablet of Deconex IR contains 385 mg of guaifenesin and 10 mg of phenylephrine.
Adults and children 12 years of age or older: The typical dose is 1 tablet by mouth every 4 hours as needed. Don't take more than 6 tablets in a 24-hour period.
Children 6 to under 12 years of age: The typical dose is half a tablet by mouth every 4 hours as needed. Don't take more than 3 tablets in a 24-hour period.
Children under 6 years of age: Ask your child's pediatrician.
Currently take or have taken an monoamine oxidase inhibitor (MAOI) in the last 2 weeks
Short-term relief of runny or stuffy nose due to allergies or the common cold
Loosens mucus to ease chest congestion
Sinus congestion and pressure
Loosen phlegm (mucus) in the lungs to make it easier to cough up
Short-term relief of cough and stuffy nose (nasal congestion)
Sinus congestion and pressure
Stuffy nose
Headache
Minor aches and pains
Phlegm (mucus) in the lungs
Fever
By signing up, I agree to GoodRx's Terms and Privacy Policy, and to receive marketing messages from GoodRx.
Centers for Disease Control and Prevention. (2024). About the PROTECT initiative.
Edinoff, A. N., et al. (2022). Clinically relevant drug interactions with monoamine oxidase inhibitors. Health Psychology Research.
Poly Pharmaceuticals, Inc. (2024). Deconex IR- guaifenesin and phenylephrine hcl tablet [package insert]. DailyMed.
Research prescriptions and over-the-counter medications from A to Z, compare drug prices, and start saving.