Lozenges for Upper Respiratory Symptoms
Lozenges containing topical anesthetics (such as amylmetacresol/2,4-dichlorobenzyl alcohol, hexylresorcinol, or menthol) provide effective temporary symptomatic relief for sore throat pain associated with upper respiratory tract infections, though they represent a choking hazard in young children. 1
Evidence for Efficacy
Sore Throat Relief
- Lozenges with topical anesthetics provide rapid onset of pain relief, typically within 1-10 minutes of administration. 2
- Hexylresorcinol lozenges demonstrated superiority over placebo for throat soreness, sore throat relief, and difficulty swallowing in randomized controlled trials. 2
- AMC/DCBA lozenges (with or without lidocaine) also showed superiority over placebo for multiple secondary endpoints related to throat pain. 2
- The analgesic effect is temporary but can provide meaningful relief during the acute phase of symptoms. 1
Mechanism of Action
- Topical anesthetics in lozenges (such as ambroxol, lidocaine, and benzocaine) provide temporary symptomatic relief through local numbing effects. 1
- Menthol lozenges work through cold and menthol-sensitive receptors to provide short-term cough suppression. 1
- Some lozenges (AMC/DCBA and hexylresorcinol) have demonstrated virucidal effects in vitro against respiratory viruses, though clinical significance remains unclear. 3
Practical Recommendations
When to Use
- Lozenges are appropriate for adults and older children with acute pharyngitis or sore throat due to viral upper respiratory tract infections. 1
- They should be considered as part of symptomatic management alongside analgesics like NSAIDs or acetaminophen. 1
- Menthol lozenges can be recommended for patients with cough associated with upper respiratory infections. 1
Important Caveats
- Lozenges represent a choking hazard for young children and should be avoided in this population. 1
- The benefit is purely symptomatic—lozenges do not shorten the duration of illness or prevent complications. 1
- Patients should be counseled that most upper respiratory symptoms resolve within one week without specific treatment. 1
What Does NOT Work
Zinc Lozenges
- Evidence for zinc-containing lozenges remains conflicting and inconsistent. 1
- While some studies showed zinc gluconate lozenges (≥75 mg/day) may reduce common cold duration when started within 24 hours, other studies and meta-analyses disputed this conclusion. 1
- Side effects include bad taste and nausea, which must be weighed against uncertain benefits. 1
- The American College of Chest Physicians notes zinc preparations are not recommended for acute cough due to common cold. 4
Adjunctive Measures
- NSAIDs (ibuprofen, naproxen) or acetaminophen should be the primary analgesic therapy, as they provide more consistent pain relief than lozenges alone. 1
- Simple home remedies like honey and lemon mixtures are reasonable first-line approaches. 1, 4
- Warm salt water gargles are commonly used but lack detailed study evidence. 1
- Adequate hydration should be encouraged. 4