What cough medication can be administered through a Gastrostomy tube (G-tube)?

Cough Medications for G-Tube Administration

Direct Answer

Liquid formulations of codeine (codeine linctus 15 mg/5 mL or codeine phosphate oral solution) and morphine sulfate oral solution (10 mg/5 mL) can be safely administered through a G-tube for distressing cough, with doses of 15-30 mg codeine every 4 hours or 2.5-5 mg morphine every 4 hours as needed. 1

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Recommended Medications and Dosing

First-Line Option: Codeine Preparations

• Codeine linctus (15 mg/5 mL) or codeine phosphate tablets crushed and dissolved: Start with 15-30 mg every 4 hours as needed, up to four doses in 24 hours 1
• If necessary, increase to a maximum of 30-60 mg four times daily (maximum 240 mg in 24 hours) 1
• Liquid formulations are preferred for G-tube administration to ensure accurate dosing and prevent tube occlusion 1

Second-Line Option: Morphine Sulfate

• Morphine sulfate oral solution (10 mg/5 mL): Start with 2.5-5 mg every 4 hours as required 1
• Can increase to 5-10 mg every 4 hours based on response 1
• If the patient is already taking regular morphine for other indications, increase the regular dose by one-third rather than adding separate doses 1

Alternative: Dextromethorphan

• Dextromethorphan liquid formulation: While commonly available over-the-counter, the generally recommended dose of 15-30 mg is likely subtherapeutic 1
• Maximum cough suppression occurs at 60 mg and can be prolonged 1
• Dextromethorphan has been shown to be as effective as codeine with fewer side effects in research studies 2, 3

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Critical Administration Guidelines for G-Tubes

Proper Technique

• Flush the G-tube with 30 mL of water before medication administration to ensure patency 1
• Administer each medication individually through the tube 1
• Flush with 30 mL of water after each medication to prevent tube occlusion and ensure complete dose delivery 1
• Use only ENFit-compatible syringes (ISO 80369-3 standard) to prevent misconnection errors 1

Medication Preparation

• Use liquid formulations whenever possible rather than crushing tablets 1
• If tablets must be crushed, ensure complete dissolution in water before administration 1
• Avoid mixing multiple medications together before administration due to potential drug-drug interactions 1

Timing Considerations

• Consider the site of the G-tube tip (gastric vs. jejunal) as this affects drug absorption and efficacy 1
• For patients on continuous enteral feeding, medications that bind to formula may need to be given separately with feeding paused 1

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Important Caveats and Contraindications

When NOT to Use Cough Suppressants

• Avoid cough suppressants in chronic bronchitis and bronchiectasis because they cause sputum retention 1
• In patients with tracheostomy, traditional cough suppressants are contraindicated as the cough reflex serves a critical protective function to clear secretions 4
• Do not suppress productive cough where secretion clearance is necessary 1

Side Effect Profile

• Opiate antitussives (codeine, morphine) have significant adverse effects including constipation, sedation, and respiratory depression 1
• Dextromethorphan has a more favorable safety profile with infrequent and usually non-severe adverse reactions 3
• Monitor for dose-related neurological, cardiovascular, and gastrointestinal disturbances with dextromethorphan 3

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Common Pitfalls to Avoid

Dosing Errors

• Do not shake low-dose ENFit tip syringes to remove drug moat, as this exposes the environment to medication and affects delivered dose 1
• Verify correct dosing when using specialized ENFit syringes, as design features may inadvertently alter the quantity administered 1

Drug Interactions

• Never combine dextromethorphan with monoamine oxidase inhibitors (MAOIs), as this represents a significant safety hazard 3
• Check for potential interactions between cough medications and enteral formula, particularly with continuous feeding 1

Tube Occlusion Risk

• Inadequate flushing is the most common cause of G-tube occlusion when administering medications 1
• Using at least 30 mL of water for irrigation reduces tube occlusion risk, particularly with small-diameter tubes 1

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When Cough Suppressants Are Appropriate

Indications for Treatment

• Only use cough suppressants when cough is distressing and interferes with daily activities or sleep 1
• Simple non-drug measures such as honey (one teaspoon) should be tried first before pharmacological intervention 1
• Central modulation of the cough reflex through simple voluntary suppression may be sufficient in some cases 1

Non-Pharmacological Alternatives

• Simple drinks and linctuses may provide benefit through central cough reflex modulation 1
• "Home remedies" such as honey and lemon are the simplest and cheapest initial approach 1
• These measures may be as effective as medications for acute viral cough, which is almost invariably benign 1