Generic Name

  • Dextromethorphan HBr
  • Guaifenesin USP

Drug class: Antitussive; Expectorant

Active ingredient: Dextromethorphan HBr 10 mg, Guaifenesin USP 200 mg (per capsule)

Inactive ingredients: carnauba wax, cellulose, colloidal silicon dioxide, crospovidone, D&C Yellow No. 10 Aluminum Lake,FD&C Blue No. 1 Aluminum Lake, gelatin, hypromellose, magnesium stearate, microcrystalline cellulose, polyethylene glycol, polysorbate 80, povidone, pregelatinized starch, sodium lauryl sulfate, titanium dioxide.

TheraFlu Flu & Cough capsules are available over the counter without a prescription. They are sold under the brand name TheraFlu.

TheraFlu Flu & Cough is an over-the-counter medication that can help relieve symptoms of the flu and common cold. It contains a combination of antihistamines and decongestants to help reduce congestion, sneezing, and runny nose. TheraFlu can also help relieve coughing, sore throat, and fever.

If you have the flu or a cold, talk to your doctor about whether TheraFlu is right for you. You should start taking it as soon as possible after you experience symptoms. TheraFlu is available in both liquid and tablet form. It can be taken with or without food.

Common side effects of TheraFlu include drowsiness, dry mouth, and upset stomach. If you experience any of these side effects, they should go away within a few days. If they persist or are bothersome, talk to your doctor.

TheraFlu can interact with other medications, so be sure to tell your doctor about all the drugs you are taking before starting TheraFlu. Do not take TheraFlu if you are allergic to any of its ingredients.

If you have the flu or a cold, TheraFlu may help relieve your symptoms. However, it is important to see a doctor if your symptoms worsen or do not improve after taking TheraFlu. Seek medical help immediately if you experience any serious side effects, such as difficulty breathing, chest pain, or rash.

PHARMACOKINETICS

Absorption: Bioavailability of the tablet formulation is unpredictable due to erratic absorption. Theraflu® Warming Relief Nighttime Severe Cold & cough powder packets for oral solution and Theraflu® ExpressMax® Severe Cold & Flu Berry Flavor powder packets for oral solution both demonstrate bioavailability similar to that of the equivalent amount of dextromethorphan HBr in liquid form.

Distribution: The mean apparent volume of distribution at steady state is 12 L/kg. Protein Binding: In vitro, dextromethorphan and guaifenesin are highly bound to human plasma proteins (>99%).Metabolism and Excretion: Dextromethorphan is metabolized by the liver to dextrorphan and 3-methoxymorphinan. In vitro studies suggest that CYP2D6 may be responsible for some of the metabolism of dextromethorphan to dextrorphan. Guaifenesin is metabolized in the liver to guaiacol glucuronide.

Dextrorphan, a active metabolite, is eliminated primarily by renal excretion. The mean elimination half-life of dextrorphan following a 10 mg dose of dextromethorphan was 5.8 hours. Less than 5% of an oral dose of guaifenesin is recovered in the urine as unchanged drug; more than 95% of the dose is eliminated in the urine as conjugates of glucuronic and sulfuric acids.

Special Populations

Elderly: The mean elimination half-life of dextrorphan following a 10 mg dose of dextromethorphan was not significantly different in 12 elderly subjects (>65 years old, 6 men and 6 women) compared to 12 young subjects (18 to 40 years old, 6 men and 6 women).

Gender: Results from a population pharmacokinetic analysis indicate that gender does not have a significant effect on the pharmacokinetics of dextromethorphan or guaifenesin.

Pediatric: The pharmacokinetics of dextromethorphan have been evaluated in pediatric subjects 3 months to 12 years of age following a single 10 mg dose (n=22).(19,20) Compared to adults, clearance was decreased and apparent volume of distribution was increased in children 3 months to 4 years of age. In children 5 to 12 years of age, apparent clearance and apparent volume of distribution were similar to those seen in adults.

Renal Impairment: Following a single 10 mg oral dose of dextromethorphan HBr in 8 subjects with mild (CLcr=50-80 mL/min/1.73 m²) or moderate (CLcr=30-49 mL/min/1.73 m²) renal impairment, mean plasma clearance of dextrorphan was decreased by 29% and mean apparent volume of distribution was increased by 36%.(21) The pharmacokinetics of dextromethorphan have not been studied in subjects with severe renal impairment (CLcr<30 mL/min/1.73 m²).

Hepatic Impairment: Following a single 10 mg oral dose of dextromethorphan HBr in 8 subjects with mild (n=3, Child-Pugh score 5-6) or moderate (n=5, Child-Pugh score 7-9) hepatic impairment, mean plasma clearance of dextrorphan was decreased by 38% and mean apparent volume of distribution was increased by 54%.(22,23) The pharmacokinetics of dextromethorphan have not been studied in subjects with severe hepatic impairment (Child-Pugh score >9).

Drug-Drug Interactions: In vitro studies indicate that CYP2D6 is the major enzyme responsible for the metabolism of dextromethorphan to its active metabolite, dextrorphan. Quetiapine (a CYP2D6 inhibitor) given as a single 50 mg dose to healthy volunteers decreased mean plasma clearance of dextrorphan by 36%. When quetiapine (150 mg BID for 5 days) was co-administered with dextromethorphan (30 mg QID for 5 days), the mean plasma clearance of dextrorphan was decreased by 59%. When fluoxetine (a CYP2D6 inhibitor) was given as a single 20 mg dose to healthy volunteers, the mean plasma clearance of dextrorphan was decreased by 21% compared to dextrorphan clearance in the absence of fluoxetine.

Benefits

The active ingredients in TheraFlu – dextromethorphan and guaifenesin – are expectorants that can help to thin and loosen mucus in the chest and throat, making it easier to cough up. This can help to relieve chest congestion and make it easier to breathe.

Dextromethorphan is a cough suppressant that works by depressing the part of the brain that triggers the coughing reflex. This can help to relieve coughing and make it less frequent.

Guaifenesin is an expectorant that helps to break down mucus in the chest and throat, making it easier to cough up. This can help to relieve chest congestion.

TheraFlu can help to relieve cold and flu symptoms including:

  • coughing
  • chest congestion
  • sore throat pain
  • nasal congestion
  • runny nose

TheraFlu can be used by adults and children aged 12 years and over. It is available in a range of formulations, including tablets, capsules, powder sachets, and liquid. It is important to follow the instructions on the packaging carefully to ensure that the correct dose is taken. TheraFlu should not be used for more than 7 days unless directed by a healthcare professional.

If you are pregnant or breastfeeding, you should speak to your doctor before taking TheraFlu as it may not be suitable for you. TheraFlu may interact with other medications, so it is important to speak to your doctor or pharmacist if you are taking any other medication, including over-the-counter medicines.

Side Effects

TheraFlu may cause side effects in some people, the most common of which include:

  • nausea
  • vomiting
  • stomach pain

If you experience any side effects, you should speak to your doctor or pharmacist. TheraFlu is a safe and effective way to relieve cold and flu symptoms. However, as with all medications, it is important to speak to a healthcare professional before taking it.

Dosage

For adults and children 12 years and over: Take 2 capsules every 4 to 6 hours, as needed.

Do not take more than 8 capsules in 24 hours.

If you are taking other medications, please speak to your doctor or pharmacist before taking TheraFlu.