Mucolytic Pregnancy: Not recommended during the first trimester of pregnancy, although tests in mammalian species revealed no teratogenic effects. It is unknown whether carbocisteine/metabolites are excreted in human milk.

Carbocisteine

Brand names: Mucodyne

Carbocisteine is an oral mucolytic used to reduce sputum viscosity in chronic respiratory conditions such as COPD with a productive cough. Treatment should be reviewed and stopped if there is no benefit within a few weeks.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: Initial daily dose 2250 mg in divided doses, reducing to 1500 mg daily in divided doses once a satisfactory response is obtained

Route: Oral

Frequency: Three times a day (e.g. 15 ml of the 250 mg/5 ml syrup three times a day, reducing to 10 ml three times a day)

SPC quotes dosage in terms of the 250 mg/5 ml syrup; use the supplied measuring device (syringe graduated per 0.25 ml; 0.25 ml = 12.5 mg carbocisteine). Paediatric doses in the SPC are stated as volumes, not per kg: 2-5 years 1.25-2.5 ml four times a day; 6-12 years 5 ml three times a day; contraindicated in children under 2 years. Verify all paediatric use against a children's formulary. Special precautions in asthmatic patients with a history of bronchospasm, severe respiratory failure and debilitated patients; concomitant antitussive medication is not recommended. Source: eMC SPC for Carbocisteine 250 mg/5 ml syrup (no US label in bundle).

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

Use in children less than 2 years of age
Active peptic ulceration
Hypersensitivity to the active substance or to any of the excipients

Side effects

Nausea, vomiting and diarrhoea (uncommon)
Urticaria and bronchospasm (rare) - special attention in asthmatic patients
Headache, dizziness, palpitations (rare)
Gastrointestinal bleeding (very rare)
Stevens-Johnson syndrome, erythema multiforme (frequency not known)
Hypothyroidism (frequency not known)

Interactions

SPC section 4.5 states: no drug interactions have been identified

Clinical monograph

How it works

It alters the structure of bronchial mucus by affecting the sialomucin component, reducing its viscosity and aiding expectoration. This makes secretions easier to clear.

Prescribing in practice

Contraindicated in active peptic ulceration because mucolytics may disrupt the protective gastric mucosal barrier; use cautiously in those with a history of peptic ulcer.
Rare reports of severe cutaneous reactions mean treatment should be stopped at the first sign of rash or mucosal lesions.
Initiate at a higher dose and reduce once a satisfactory response is achieved.

Monitoring

Review symptomatic benefit after a short trial and watch for gastrointestinal bleeding or skin reactions.

Counselling the patient

This medicine thins phlegm to make coughing it up easier.
Report black or bloodstained stools, indigestion, or any rash.
Tell your prescriber if there is no improvement after a few weeks so treatment can be reviewed.

Evidence & guidelines

Mucolytic therapy is recognised in UK COPD guidance as an option for patients with a chronic productive cough who report symptomatic benefit.

Reference: BRONCHUS Trial (Zheng et al, Lancet 2008); NICE NG115 COPD; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Drugs

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