What Are the White Beads in Tussionex?
The white beads in Tussionex are extended-release polymer-coated beads containing hydrocodone (an opioid antitussive) and chlorpheniramine (a first-generation antihistamine), designed to provide sustained drug release over 12 hours.
Formulation Components
The white beads represent a specialized extended-release delivery system that contains:
- Hydrocodone polistirex: An opioid cough suppressant that acts centrally on the medullary cough center 1, 2
- Chlorpheniramine polistirex: A first-generation H1-antihistamine with anticholinergic properties that provides additional cough suppression and dries respiratory secretions 1
Mechanism of the Bead Technology
The polymer-coated bead formulation allows for:
- Sustained release over 12-hour intervals: This extended-release technology permits twice-daily dosing rather than the multiple daily doses required with immediate-release hydrocodone formulations 3
- Gradual drug absorption: The beads dissolve slowly in the gastrointestinal tract, maintaining therapeutic drug levels throughout the dosing interval 2
Clinical Pharmacology
Hydrocodone Component
- Functions as a mu- and delta-opioid receptor agonist requiring systemic absorption to produce antitussive effects 2
- Effective for cough suppression in doses ranging from 5-30 mg/day, with median effective dose of 10 mg/day 4
- Approximately equipotent with oral morphine at a 1:1 ratio 4, 3
Chlorpheniramine Component
- Provides anticholinergic effects including drying of respiratory secretions, which may explain better control of rhinorrhea compared to second-generation antihistamines 1
- Has sedating properties with plasma half-life of 2-6 hours, though the extended-release formulation modifies this profile 1
- Adult dosing of immediate-release chlorpheniramine is typically 4 mg four times daily, but the extended-release beads allow for less frequent administration 1
Important Safety Considerations
Critical contraindication: Hydrocodone-containing cough medications should not be used in patients under 18 years of age due to unfavorable benefit-risk profile, including risk of respiratory depression and lack of robust efficacy data in pediatric populations 5
Common Adverse Effects
- CNS depression and sedation: Both components contribute to sedation, with first-generation antihistamines causing performance impairment that persists even with bedtime-only dosing due to prolonged half-life 1
- Anticholinergic effects: Dry mouth, constipation, urinary retention, and potential precipitation of narrow-angle glaucoma, particularly in elderly patients 1
- Respiratory depression: The opioid component carries risk of life-threatening respiratory depression, especially with overdose 5
High-Risk Populations
- Elderly patients: Increased sensitivity to anticholinergic effects and higher incidence of comorbid conditions like prostatic hypertrophy and cognitive impairment 1
- Hepatic impairment: Chlorpheniramine should be avoided in severe liver disease as sedating effects are inappropriate and may precipitate hepatic coma 1
- Renal impairment: Dose adjustments may be necessary due to potential accumulation of renally cleared metabolites 3
Clinical Context
The combination of hydrocodone and chlorpheniramine in extended-release beads provides:
- Dual mechanism cough suppression: Central opioid-mediated suppression plus antihistamine effects 1, 6
- Convenience of twice-daily dosing: Unlike immediate-release hydrocodone formulations that require dosing every 4-6 hours 3
- Additional symptom control: The antihistamine component addresses upper respiratory symptoms beyond cough alone 6, 7
Important caveat: The extended-release nature of these beads means they should never be crushed, chewed, or dissolved, as this would result in rapid release of potentially fatal doses of hydrocodone 5.