This information is intended for use by health professionals

1. Name of the medicinal product

Benylin Mucus Cough Menthol flavour 100 mg/5 ml Oral Solution

2. Qualitative and quantitative composition

This product contains 20 mg guaifenesin in each ml (100mg in 5ml).

Each ml also contains:

Ethanol 39.7mg

Ponceau 4R (E124) 0.05mg

Sodium 1.8mg



For a full list of excipients, see section 6.1.

3. Pharmaceutical form

Oral solution

Clear to slightly opalescent red liquid

4. Clinical particulars
4.1 Therapeutic indications

This product is indicated to help loosen phlegm and thin bronchial secretions associated with productive cough, for use in adults and adolescents over 12 years.

4.2 Posology and method of administration

Adults and adolescents over 12 years:

For oral administration: 10 ml (200mg guaifenesin) 4 times a day.

Maximum daily dose: 40ml (800mg guaifenesin)

Children under 12 years:

Not recommended.

The Elderly:

As for adults.

Hepatic/renal dysfunction

Caution should be exercised in severe hepatic and severe renal impairment.

If cough persists for more than 7 days, tends to recur, or is accompanied by a fever, rash, or persistent headache, a physician should be consulted.

4.3 Contraindications

This product is contraindicated in individuals with known hypersensitivity to the active substance or to any of the excipients.

4.4 Special warnings and precautions for use

This product should not be used for persistent or chronic cough, such as occurs with asthma, or where cough is accompanied by excessive secretions, unless directed by a physician.

A persistent cough may be a sign of a serious condition. If cough persists for more than 7 days, tends to recur, or is accompanied by a fever, rash, or persistent headache, a physician should be consulted.

Caution should be exercised when using the product in the presence of severe renal or severe hepatic impairment.

The concomitant use of cough suppressants is not recommended.

Patients with rare hereditary problems of fructose intolerance or glucose galactose malabsorption should not take this medicine.

This product contains 4.7 vol % ethanol (alcohol), i.e. up to 400 mg per dose, equivalent to approximately 10 ml beer, 4 ml wine per 10 ml dose. This can be harmful for those suffering from alcoholism. The ethanol content should be taken into account in pregnant or breast-feeding women, children and high-risk groups such as patients with liver or kidney disease or epilepsy.

This product contains Ponceau 4R (E124) red colouring which may cause allergic reactions.

This product contains 17.6mg sodium per 10ml dose. This should be taken into consideration by those on a controlled sodium diet.

4.5 Interaction with other medicinal products and other forms of interaction

If urine is collected within 24 hours of a dose of this product a metabolite of guaifenesin may cause a colour interference with laboratory determinations of urinary 5-hydroxyindoleacetic acid 5-HIAA) and vanillylmandelic acid (VMA).

Expectorants such as guaifenesin should not be combined with cough suppressants in the treatment of cough since the combination is illogical and patients may be exposed to unnecessary adverse effects.

No interaction studies have been performed which revealed an interaction with guaifenesin.

4.6 Fertility, pregnancy and lactation


There are no or limited amount of data from the use of Guaifenesin in pregnant women. Animal studies are insufficient with respect to reproductive toxicity (see section 5.3). Guaifenesin Cough Menthol Flavour 20 mg/ml Oral Solution is not recommended during pregnancy and in women of childbearing potential not using contraception.


Guaifenesin is excreted in breast milk in small amounts. There is insufficient information on the effects of Guaifenesin in newborns/infants. A decision must be made whether to discontinue breast-feeding or to discontinue/abstain from Guaifenesin Cough Menthol flavour 100 mg/5 ml Oral Solution therapy, taking into account the benefit of breast feeding for the child and the benefit of therapy for the woman.


There is insufficient information available to determine whether guaifenesin has the potential to impair fertility.

4.7 Effects on ability to drive and use machines

Guaifenesin has no or negligible influence on the ability to drive and use machines.

4.8 Undesirable effects

The following side effects may be associated with the use of guaifenesin:

Immune System Disorders: Hypersensitivity reactions including pruritus and urticaria, rash (frequency – not known).

Gastrointestinal disorders: Abdominal pain upper, diarrhoea, nausea, vomiting (frequency – not known).

Reporting of suspected adverse reactions

Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme at:

4.9 Overdose

Symptoms and signs

The symptoms and signs of overdose may include gastro-intestinal discomfort, nausea and drowsiness.

When taken in excess, guaifenesin may cause renal calculi.


Treatment should be symptomatic and supportive.

5. Pharmacological properties
5.1 Pharmacodynamic properties

ATC Code: R05CA03; Pharmacotherapeutic Group: Cough and Cold Preparations, Expectorants

Guaifenesin is thought to exert its pharmacological action by stimulating receptors in the gastric mucosa. This increases the output from secretory glands of the gastrointestinal system and reflexly increases the flow of fluids from glands lining the respiratory tract. The result is an increase in volume and decrease in viscosity of bronchial secretions. Other actions may include stimulating vagal nerve endings in bronchial secretory glands and stimulating certain centres in the brain, which in turn enhance respiratory fluid flow. Guaifenesin produces its expectorant action within 24 hours.

5.2 Pharmacokinetic properties

There is no information available on the pharmacokinetics of guaifenesin in special populations.


Guaifenesin is well absorbed from the gastro-intestinal tract following oral administration, although limited information is available on its pharmacokinetics. After the administration of 600 mg guaifenesin to healthy adult volunteers, the Cmax was approximately 1.4 ug/ml, with tmax occurring approximately 15 minutes after drug administration.


No information is available on the distribution of guaifenesin in humans.

Metabolism and elimination

Guaifenesin appears to undergo both oxidation and demethylation. Following an oral dose of 600 mg guaifenesin to 3 healthy male volunteers, the t½ was approximately 1 hour and the drug was not detectable in the blood after approximately 8 hours.

5.3 Preclinical safety data


There is insufficient information available to determine whether guaifenesin has carcinogenic potential.


There is insufficient information available to determine whether guaifenesin has mutagenic potential.


There is insufficient information available to determine whether guaifenesin has teratogenic potential.


There is insufficient information available to determine whether guaifenesin has the potential to impair fertility.

6. Pharmaceutical particulars
6.1 List of excipients

Xanthan gum

Sodium chloride

Saccharin sodium

Ammonium glycyrrhizate

Sodium benzoate (E211)

Citric acid anhydrous

Sodium citrate

Macrogol glycerol hydroxystearate 40


Raspberry flavour F2126 (includes ethanol, glucose and fructose)

Caramel (E150) (includes glucose)

Ponceau 4R (E124)


Macrogol 1500

Propylene glycol

Ethanol 96%

Purified water

6.2 Incompatibilities

Not applicable.

6.3 Shelf life

3 years

In-use: 4 weeks

6.4 Special precautions for storage

Do not store above 25°C

Store in the original container to protect from light

6.5 Nature and contents of container

Type III, Amber glass bottle, containing 150ml, fitted with:

A plastic child resistant cap fitted with a PET-faced wad.

A plastic dosing cup marked with a 10ml graduation may be included in this pack.

6.6 Special precautions for disposal and other handling

No special requirements.

Medicines should not be disposed of via wastewater or household waste. Ask your pharmacist how to dispose of medicines no longer required (these should be disposed of in line with local requirements). These measures will help to protect the environment.

7. Marketing authorisation holder

McNeil Products Limited

Foundation Park

Roxborough Way




United Kingdom

8. Marketing authorisation number(s)

PL 15513/0165

9. Date of first authorisation/renewal of the authorisation

5 May 2010

10. Date of revision of the text

30 June 2015