How to Use Lidocaine Solution for Sore Throat
For adults with acute sore throat, use viscous lidocaine 2% solution at 15 mL per application, swish in the mouth for 1-2 minutes before spitting out (do not swallow), and repeat every 3 hours as needed, particularly before meals, with a maximum of approximately 31.5 mL per day for a 70 kg patient. 1, 2
Specific Dosing Instructions
- Apply 15 mL of viscous lidocaine 2% solution per application 1, 2
- Hold the solution in your mouth for 1-2 minutes to allow adequate contact with the painful throat tissues 1
- Spit out the solution after swishing—do not swallow it to minimize systemic absorption and reduce toxicity risk 1, 2
- Repeat every 3 hours as needed, especially before eating to facilitate swallowing 1, 2
- Avoid eating or drinking for 30 minutes after application for maximum effectiveness 2
Maximum Daily Dose and Safety Limits
- Do not exceed 9 mg/kg of lean body weight per day from all lidocaine sources combined 1, 2
- For a 70 kg patient using 2% lidocaine solution, this translates to approximately 31.5 mL maximum per day 1, 2
- Calculate dose based on lean body weight, not actual body weight 2
Warning Signs of Toxicity
Monitor for these symptoms and stop use immediately if they occur: 1, 2
- Tingling of tongue or lips
- Light-headedness or dizziness
- Tinnitus (ringing in ears)
- Slurred speech
- Muscle twitching
Clinical Context: When to Use Lidocaine
- Lidocaine is an adjunctive option when standard analgesics (ibuprofen or paracetamol) provide insufficient relief 1
- First-line treatment for sore throat should be ibuprofen or paracetamol, as these are more effective than placebo and have better safety profiles 3, 4
- Topical anesthetics like lidocaine may provide temporary symptomatic relief but are not routinely recommended as primary therapy 3
Alternative Formulations for Severe Cases
- For refractory pain, consider combination formulations with viscous lidocaine 2% plus nystatin oral suspension and sodium bicarbonate 1
- Benzydamine hydrochloride rinse every 3 hours can serve as an alternative anti-inflammatory option 1
- Lidocaine lozenges (8 mg) have demonstrated efficacy in clinical trials, with onset of pain relief within 1-10 minutes 5, 6
Important Precautions
- Avoid concurrent use of other local anesthetics to prevent exceeding maximum safe doses 2
- Not recommended for patients under 40 kg without careful dose adjustment 2
- Lozenges represent a choking hazard for young children and should be avoided in this population 3
- The FDA label for topical lidocaine products indicates application not more than 3 to 4 times daily for adults and children over 12 years 7
Common Pitfalls to Avoid
- Do not swallow viscous lidocaine—this increases systemic absorption and toxicity risk 1, 2
- Do not use lidocaine as monotherapy—combine with systemic analgesics like ibuprofen or paracetamol for optimal pain control 4, 1
- Do not exceed maximum daily dose limits—track all sources of lidocaine exposure 1, 2
- Remember that antibiotics are not indicated for most cases of sore throat unless Group A Streptococcus is confirmed or highly suspected 4