Guaifenesin 600mg modified-release tablets
Requires a prescription from a doctor or prescriber
Guaifenesin possesses a storied history, having been originally formally approved by the US FDA in 1952 and continues to be one of very few - if not perhaps the only drug that is readily available and used as an expectorant [F4525].
Safety information for pregnancy and breastfeeding
Pregnancy
Breastfeeding
Always consult your doctor or midwife before taking any medicine during pregnancy or while breastfeeding. Source: DrugBank (CC BY-NC 4.0).
Official documents, adverse reaction reporting, and safety monitoring
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Official medicine documents
Safety monitoring data
Yellow Card reports
The MHRA Yellow Card scheme collects reports of suspected side effects from healthcare professionals and patients. View the Drug Analysis Profile (iDAP) for real-world adverse reaction data.
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Submit a Yellow Card report to the MHRA
Data from the MHRA Yellow Card scheme. A reported reaction does not necessarily mean the medicine caused it. Contains public sector information licensed under the Open Government Licence v3.0.
EudraVigilance
The European Medicines Agency (EMA) collects suspected adverse reaction reports from across the EU/EEA through the EudraVigilance system. Search for safety data on this medicine.
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Suspected adverse reactions reported for Guaifenesin
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EudraVigilance data is published by the European Medicines Agency (EMA). A suspected adverse reaction is not necessarily caused by the medicine.
1 branded products available
WHO defined daily dose (DDD)
900 mg
Not a recommended dose. The DDD is the assumed average maintenance dose per day for a drug used for its main indication in adults. It is a statistical measure used for research and comparison purposes only.
Source: WHO Collaborating Centre for Drug Statistics Methodology, distributed via NHS dm+d BNF mapping files. Contains public sector information licensed under the Open Government Licence v3.0.
Therapeutically similar medicines
Similarity based on WHO Anatomical Therapeutic Chemical (ATC) classification and NHS BNF section grouping. Source data: NHS dm+d via TRUD (OGL v3.0), WHO ATC/DDD Index.
NHS prescribing volume and spending trends
Clinical guidelines and formulary information
British National Formulary
Guaifenesin
Source: British National Formulary, NICE. Joint Formulary Committee. Contains public sector information licensed under the Open Government Licence v3.0.
NICE clinical guidance(1)
Source: National Institute for Health and Care Excellence (NICE). Contains public sector information licensed under the Open Government Licence v3.0.
Check stock at pharmacies and supply information
Pharmacy stock checkers
Search for this medicine at major UK pharmacy chains. These links open the retailer's own website — results depend on their current online catalogue.
Supply & product information
Official product databases and supply status monitoring
Pharmacy links redirect to the retailer's own search and do not represent real-time stock levels. emc (electronic medicines compendium) is operated by Datapharm Ltd. Shortage information sourced from NHS Specialist Pharmacy Service (SPS), sps.nhs.uk.
Codes for healthcare professionals and prescribing systems
These codes are used by healthcare IT systems and prescribers to identify this medicine.
NHS UK identifiers
Browse tools
SNOMED CT and dm+d codes from NHS TRUD (Technology Reference data Update Distribution), licensed under the Open Government Licence v3.0. BNF codes from NHS Business Services Authority (NHSBSA). ATC codes from the WHO Collaborating Centre for Drug Statistics Methodology (whocc.no).
Active and completed clinical studies from ClinicalTrials.gov
Source: ClinicalTrials.gov, a database of the U.S. National Library of Medicine (NLM), National Institutes of Health (NIH). Data accessed via ClinicalTrials.gov API v2. Trial information is provided for research purposes and does not constitute medical advice.
Pharmacology and chemical data from DrugBank
Key facts
Drug status
Approved
Major interactions
None known
Half-life
Not available
Mechanism
Although the exact mechanism of action of guaifenesin may not yet be formally or…
Food interactions
2 warnings
Human targets
1 target
Data: DrugBank · CC BY-NC 4.0
Pharmacokinetics at a glance
Absorption
Half-life
Protein binding
Volume of distribution
116L
Metabolism
400 mg
Elimination
Clearance
94.8 L/h
Pharmacokinetic data: DrugBank · CC BY-NC 4.0
Regardless, on March 1, 2007, the FDA received a petition asking the FDA to notify the public that some antitussives, expectorants, decongestants, antihistamines, and cough/cold combinations are not known to be safe and effective in children under the age of 6 years F4525. After the negotiation between FDA and major manufacturers, a voluntary transition of labels for not using guaifenesin in children under the age of 4 years was endorsed by FDA in 2008 F4525.
Furthermore, there has also been contemporary research to suggest that guaifenesin possesses and is capable of demonstrating anticonvulsant and muscle relaxant effects to some degree possibly by acting as an NMDA receptor antagonist [A177652].
[L6100]
Although adequate and well-controlled studies in pregnant women have not been performed, the Collaborative Perinatal Project monitored 197 mother-child pairs exposed to guaifenesin during the first trimester .
[L6100]
An increased occurrence of inguinal hernias was found in the neonates .
[L6100]
However, congenital defects were not strongly associated with guaifenesin use during pregnancy in 2 large groups of mother-child pairs .
[L6100]
Moreover, guaifenesin is excreted in breast milk in small quantities .
[L6100]
Subsequently, caution should be exercised by balancing the potential benefit of treatment against any possible risks .
[L6100]
Additionally, an LD50 value of 1510 mg/kg (rat, oral) has been reported for guaifenesin MSDS.
Consequently, while it is generally proposed that guaifenesin functions as an expectorant by helping to loosen phlegm (mucus) and thin bronchial secretions to rid the bronchial passageways of bothersome mucus and make coughs more productive, there has also been research to suggest that guaifenesin possesses and is capable of demonstrating anticonvulsant and muscle relaxant effects to some degree possibly by acting as an NMDA receptor antagonist [A177652].
How the body processes this drug — absorption, distribution, metabolism, and elimination
[A177676][L6100]
Moreover, it has been observed that guaifenesin also experiences both oxidation and demethylation .
[A177676]
In particular, the medication is quickly metabolized hepatically by way of oxidation to β-(2-methoxyphenoxy)-lactic acid .
[A177676]
Furthermore, guaifenesin is also demethylated by O-demethylase in liver microsomes to the point where about 40% of an administered dose is excreted as this metabolite in the urine within 3 hours .
[A177676]
In fact, O-demethylase appears to be the primary enzyme for the metabolism of guaifenesin and the primary metabolites of the substance are β-(2-methoxyphenoxy)-lactic acid and the demethylated hydroxyguaifenesin, both of which are themselves inactive moieties .
[A177676]
Proteins and enzymes this drug interacts with in the body
GluN3B subunit also binds D-serine and, in the absence of glycine, activates glycinergic receptor complexes, but with lower efficacy than glycine (By similarity). Each GluN3 subunit confers differential attributes to channel properties, including activation, deactivation and desensitization kinetics, pH sensitivity, Ca2(+) permeability, and binding to allosteric modulators (By similarity)
ATC R05CA03
Chemical identifiers
CAS, UNII, InChI Key and database cross-references
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Chemical identifiers
CAS, UNII, InChI Key and database cross-references
Linked compound data from DrugBank Open Data (CC BY-NC 4.0)
Guaifenesin
Additional database identifiers
Drugs Product Database (DPD)
9615
ChemSpider
3396
BindingDB
50240098
HUGO Gene Nomenclature Committee (HGNC)
HGNC:4584
GenAtlas
GRIN1
GeneCards
GRIN1
GenBank Gene Database
D13515
GenBank Protein Database
219920
Guide to Pharmacology
455
UniProt Accession
NMDZ1_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:4585
GenAtlas
GRIN2A
GeneCards
GRIN2A
GenBank Gene Database
U09002
GenBank Protein Database
558749
Guide to Pharmacology
456
UniProt Accession
NMDE1_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:4586
GenAtlas
GRIN2B
GeneCards
GRIN2B
GenBank Gene Database
U90278
GenBank Protein Database
1899202
Guide to Pharmacology
457
UniProt Accession
NMDE2_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:4587
GenAtlas
GRIN2C
GeneCards
GRIN2C
GenBank Gene Database
L76224
GenBank Protein Database
1196449
Guide to Pharmacology
458
UniProt Accession
NMDE3_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:4588
GenAtlas
GRIN2D
GeneCards
GRIN2D
GenBank Gene Database
U77783
GenBank Protein Database
2444026
UniProt Accession
NMDE4_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:16767
GenAtlas
GRIN3A
GeneCards
GRIN3A
GenBank Gene Database
AJ416950
GenBank Protein Database
20372905
UniProt Accession
NMD3A_HUMAN
HUGO Gene Nomenclature Committee (HGNC)
HGNC:16768
GenAtlas
GRIN3B
GeneCards
GRIN3B
GenBank Gene Database
AC004528
GenBank Protein Database
3025446
UniProt Accession
NMD3B_HUMAN
International reference pricing
Reference pricing from DrugBank. Prices are indicative and may not reflect current UK costs.
Source: DrugBank. Used under CC BY-NC 4.0 academic licence for non-commercial purposes.
Patent information
3 active patents, 3 expired
Source: DrugBank · CC BY-NC 4.0. Patent data sourced from national patent offices. Expiry dates may not reflect extensions, regulatory exclusivity periods, or legal challenges.
DrugBank citations
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