What is Codeine Linctus?

Codeine Linctus (also known as Codeine Phosphate Linctus or Codeine Syrup) is a prescription-only oral liquid medication primarily used as a cough suppressant (antitussive). It’s formulated as a syrup containing codeine phosphate (typically 15 mg per 5 mL dose) dissolved in a sweetened, flavored vehicle, often with ingredients like glycerol, citric acid, and preservatives.

Key Uses

• Dry, irritating cough: Suppresses the cough reflex in the brain’s medulla oblongata, providing relief for non-productive coughs (e.g., due to colds, flu, or upper respiratory infections).
• Occasional mild pain relief: Codeine is a weak opioid analgesic, so it’s sometimes used for short-term pain management.
• Not for productive (chesty) coughs: It can thicken mucus and worsen conditions like bronchitis or pneumonia.

How It Works

Codeine is a prodrug metabolized in the liver by the enzyme CYP2D6 into morphine, which acts on mu-opioid receptors in the central nervous system to:

• Reduce cough reflex sensitivity.
• Provide mild analgesia and sedation.

About 5-10% of people are “poor metabolizers” due to CYP2D6 genetics, experiencing little effect.

Dosage (Adults, Typical)

• Standard dose: 5-10 mL (15-30 mg codeine) every 4-6 hours, max 4 doses/day (120 mg total).
• Children: Not recommended under 12; restricted use in 12-18 due to risks.
• Always follow prescriber instructions; shake well before use.

Side Effects

Common (5-10% of users):

• Drowsiness, dizziness, constipation.
• Nausea, dry mouth.

Serious (seek medical help):

Warnings & Contraindications

• Opioid risks: High abuse potential; classified as a controlled substance (Schedule 5 in UK, Schedule II/III elsewhere). Overdose can cause coma/death—naloxone reverses it.
• Do not use with: Alcohol, sedatives, other opioids (e.g., tramadol), MAOIs, or in acute asthma/COPD.
• Pregnancy/Breastfeeding: Avoid (passes into milk, risks neonatal sedation).
• Driving: Impairs; avoid until effects known.
• Overdose symptoms: Pinpoint pupils, confusion, blue lips—call emergency services.

Availability & Regulations

• Prescription-only in most countries (e.g., UK, US, Australia). Not OTC due to opioid status.
• UK specifics: BP (British Pharmacopoeia) formulation; “Codeine Linctus BP 15 mg/5 mL”.
• Alternatives: Dextromethorphan (e.g., Robitussin DM) for non-opioid cough relief; guaifenesin for expectorants.
• Street misuse: Sometimes abused for euphoria (“lean” with soda), but pure linctus is dilute.

Evidence & Sources

• Supported by NICE guidelines (UK) for short-term cough suppression.
• Studies (e.g., Cochrane Review 2014): Modest efficacy vs. placebo for cough; better for nocturnal relief.
• FDA/EMA warnings emphasize risks post-2017 codeine restrictions in kids.

Consult a doctor/pharmacist before use. This is general info—not medical advice. If you have symptoms or need sourcing, see a healthcare professional.