Guaifenesin and phenylephrine

Generic name: guaifenesin and phenylephrine [ gwye-FEN-e-sin-and-FEN-il-EFF-rin ]
Brand names: Deconex IR, Despec, ED Bron GP, Gilphex TR, Giltuss Sinus and Congestion, ... show all 120 brands Maxi-Tuss PE Jr, Mucinex Children's Stuffy Nose and Chest Congestion, Mucus Relief Sinus, Rescon-GG, Supress-PE, Aldex G, Aquatab D, D-Phen 1000, Deconex, Deconex IR, Donatussin Drops, Duravent PE, Gilphex TR, Giltuss Sinus and Congestion, Liquibid-PD, Maxi-Tuss PE Jr, MucaphEd, Mucus Relief Sinus, Nariz, Prolex D, Sudafed PE Non-Drying Sinus, Supress-PE, Xpect-PE, Sinupan, Deconsal Pediatric, Efasin, Amidal, Chemdal, Quindal, Endal, Liquibid-D, SINUvent PE, Entex LA, Entex (obsolete formulation), Crantex, Crantex LA Capsules, Amitex LA, Entex ER, Duraphen II, Crantex ER, Liquibid-D 1200, Phenavent LA, Phenavent D, Sina-12X, Deconsal II, Guaifed Caps, Guaifed PD, Phenavent, Tussbid, Phenavent PED, Nescon-PD, Pendex, Prolex PD, Aldex, Nasex, Crantex LA Tablets, Duratuss, Duratuss GP, Lusonex, Sitrex, Guaiphen-PD, Wellbid-D, Wellbid-D 1200, Xedec, Nasex-G, Gentex LA, Guaiphen-D 600, Guaiphen-D 1200, Simuc, Zotex GPX, Duomax, Guaifen PE, Norel EX, Nexphen PD, Respa-PE, Reluri, Duraphen 1000, Dynex LA, Sudex, Extendryl G, Maxiphen, Ambi 40/1000, MontePhen, Xedec II, Simuc-GP, Triaminic Chest and Nasal Congestion, Duratuss PE, Sitrex PD, Refenesen PE, Mydex, Medent-PE, Genexa LA, Nazarin, J-Max, Robitussin Head and Chest Congestion, Visonex, Zyrphen, PE-Guai, Guiadex PD, D-Tab, ExeTuss, ExeTuss-GP, Mucinex Children's Cold, Quintex, Guiatex PE, Fenesin PE IR, Medent-PEI, Liquibid PD-R, Liquibid D-R, Zoden Drops, Entex LQ, Tussi-Pres PE, Lusair, Reese Onetab Congestion and Cough, Relcof IR
Dosage forms: oral liquid (100 mg-2.5 mg/5 mL; 100 mg-5 mg/5 mL; 50 mg-2.5 mg/5 mL; 50 mg-2.5 mg/mL), ... show all 2 dosage forms oral tablet (385 mg-10 mg; 388 mg-10 mg; 390 mg-10 mg; 400 mg-10 mg)
Drug class: Upper respiratory combinations

Medically reviewed by Drugs.com on Nov 6, 2023. Written by Cerner Multum.

What is guaifenesin and phenylephrine?

Guaifenesin and phenylephrine is a combination medicine used in adults and children to treat allergy symptoms such as runny or stuffy nose, sneezing, watery eyes, itching of nose and throat, cough with mucus, sinus pain, and to reduce chest congestion caused by the common cold, hay fever, or other allergies.

There are many brands and forms of guaifenesin and phenylephrine available and not all brands are listed on this leaflet.

Guaifenesin and phenylephrine may also be used for purposes not listed in this medication guide.

Guaifenesin and phenylephrine side effects

Get emergency medical help if you have signs of an allergic reaction: hives, difficult breathing, swelling of your face, lips, tongue, or throat.

Guaifenesin and phenylephrine may cause serious side effects. Stop using guaifenesin and phenylephrine and call your doctor at once if you have:

• nervousness, dizziness, sleep problems (insomnia).

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.

Related/similar drugs

Warnings

Do not use guaifenesin and phenylephrine if you have used an MAO inhibitor in the past 14 days. A dangerous drug interaction could occur. MAO inhibitors include isocarboxazid, linezolid, methylene blue injection, phenelzine, and tranylcypromine.

Taking more than your recommended dose will not make guaifenesin and phenylephrine more effective, and may cause serious side effects.

Before taking this medicine

Do not use guaifenesin and phenylephrine if you have used an MAO inhibitor in the past 14 days. A dangerous drug interaction could occur. MAO inhibitors include isocarboxazid, linezolid, methylene blue injection, phenelzine, and tranylcypromine. Wait at least 14 days after stopping an MAO inhibitor before you take guaifenesin and phenylephrine.

Tell your doctor if you have or have ever had:

• high blood pressure;

• heart disease;

• diabetes;

• a thyroid disorder;

• urination problems due to an enlarged prostate; or

• cough with mucus or chronic cough cause by smoking, asthma, chronic obstructive pulmonary disease (COPD) or other breathing disorder.

Ask your doctor before using this medicine if you are pregnant or breastfeeding.

Do not give this medicine to a child without medical advice.

How should I take guaifenesin and phenylephrine?

Use exactly as directed on the label, or as prescribed by your doctor. Cold or cough medicine is only for short-term use.

Follow all directions when giving guaifenesin and phenylephrine to a child. Do not use the medicine to make a child sleepy. Misuse of this medicine may cause death in very young children.

Measure liquid medicine with the supplied measuring device (not a kitchen spoon).

Take the tablet with a full glass of water.

Your dose needs may change if you switch to a different brand, strength, or form of this medicine. Avoid medication errors by using exactly as directed on the label, or as prescribed by your doctor.

Taking more than your recommended dose will not make this medicine more effective, and may cause serious side effects.

Stop using this medicine and call your doctor if your symptoms do not improve or get worse after 7 days, or if you also have a fever, rash, or headaches.

Store at room temperature away from moisture and heat.

Guaifenesin and phenylephrine dosing information

Usual Adult Dose for Cough and Nasal Congestion:

Dose referred to by strength of guaiFENesin/phenylephrine (in mg) per unit of measurement:

Oral liquids:
100/5 per 5 mL:10 mL every 4 hours, maximum 6 doses per day

Oral tablets:
385/10 per tablet: 1 tablet every 4 hours, maximum 6 doses per day

388/10 per tablet: 1 tablet every 4 hours, maximum 6 doses per day

395/10 per tablet: 1 tablet every 4 hours, maximum 6 doses per day

Usual Pediatric Dose for Cough and Nasal Congestion:

Dose referred to by strength of guaiFENesin/phenylephrine (in mg) per unit of measurement:

Oral liquids:
50/2.5 per 1 mL:
2 to under 6 years: 1 mL every 4 hours, maximum 6 doses per day

100/5 per 5 mL:
12 years and older: 10 mL every 4 hours, maximum 6 doses per day
6 to under 12 years: 5 mL every 4 hours, maximum 6 doses per day

Oral tablets:
385/10 per tablet:
12 years and older: 1 tablet every 4 hours, maximum 6 doses per day
6 to under 12 years: 1/2 tablet every 4 hours, maximum 6 doses per day

388/10 per tablet:
12 years and older: 1 tablet every 4 hours, maximum 6 doses per day
6 to under 12 years: 1/2 tablet every 4 hours, maximum 6 doses per day

395/10 per tablet:
12 years and older: 1 tablet every 4 hours, maximum 6 doses per day
6 to under 12 years: 1/2 tablet every 4 hours, maximum 6 doses per day

What happens if I miss a dose?

Guaifenesin and phenylephrine is used when needed. If you are on a dosing schedule, skip any missed dose. Do not use two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while taking guaifenesin and phenylephrine?

Ask a doctor or pharmacist before taking other cough or cold medicines that may contain similar ingredients.

What other drugs will affect guaifenesin and phenylephrine?

Ask a doctor or pharmacist before using any other medicines that can cause drowsiness (such as opioid medication, sleep medicine, a muscle relaxer, or medicine for anxiety or seizures). Tell your doctor about all other medicines you use. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed here.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Medical Disclaimer

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