guaifenesin / pseudoephedrine

You can take Mucinex D (guaifenesin / pseudoephedrine) with or without food. Try taking the medication with food to help if it upsets your stomach.

Swallow the tablets whole with a full glass of water. Don't crush, break, or chew the tablets since it can change how the medication works.

You might feel nervous or have trouble sleeping after you take Mucinex D (guaifenesin / pseudoephedrine). These can be side effects of the pseudoephedrine 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. Mucinex D (guaifenesin / pseudoephedrine) might not be appropriate for you and you might need a different treatment option.

Stop using Mucinex D (guaifenesin / pseudoephedrine) 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. There might be a more appropriate treatment option for these situations.

Don't start any new medications while you're taking Mucinex D (guaifenesin / pseudoephedrine) — especially other guaifenesin or decongestant products — without talking to your primary care provider or pharmacist first. Taking certain medications with Mucinex D (guaifenesin / pseudoephedrine) 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).

Don't take Mucinex D (guaifenesin / pseudoephedrine) if you're taking or have taken a monoamine oxidase inhibitor (MAOI) like selegiline in the last 2 weeks. This combination can raise your risk for severe side effects, such as dangerously high blood pressure and dizziness. Ask your primary care provider or pharmacist for other options.

Don't take Mucinex D (guaifenesin / pseudoephedrine) until you've talked to a healthcare professional if you're pregnant or breastfeeding. It's not clear whether guaifenesin and pseudoephedrine are safe for your unborn baby. There's also a risk that taking pseudoephedrine might lower your milk supply.

Store Mucinex D (guaifenesin / pseudoephedrine) 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 Mucinex D (guaifenesin / pseudoephedrine).