Lidocaine Oral Solution

Lidocaine oral solution (often called viscous lidocaine) is a liquid form of the local anesthetic lidocaine (lidocaine hydrochloride) designed for topical use in the mouth and throat. It belongs to the amide class of local anesthetics and works by blocking nerve conduction (sodium channels) in mucous membranes, producing numbing of the applied area. In practice it is used as a topical anesthetic – a pain reliever applied inside the mouth or throat – not for injection or ingestion as a systemic drug. (The bottle itself typically notes “Not for Injection.”)

Uses/Indications: Lidocaine oral solution is indicated for relieving pain and discomfort of the mouth and throat. For example, it is used to soothe painful mouth ulcers, canker sores, inflamed gums, aphthous stomatitis, sore throat, or irritation of the oropharynx. Dentists and doctors commonly use it to numb the mouth or throat before procedures – e.g. before taking dental impressions, X-rays, endoscopy, or inserting tubes – and to reduce the gag reflex. According to medical references, lidocaine oral solution “is used to stop pain” and “to treat mouth sores”. By numbing the mucosa, it quickly relieves sharp or burning pain in the oral/pharyngeal area.

Formulation: The solution typically contains about 2–4% lidocaine (i.e. 20–40 mg per mL) mixed in a viscous base (often flavored).. For example, one common formulation (“Lidocaine Viscous 2%”) has 20 mg/mL, while other oral preparations contain 40 mg/mL of lidocaine. Inactive ingredients may include a thickener (e.g. carboxymethylcellulose), flavor (banana, etc.), preservatives, and sweeteners to make it palatable. To use, the liquid is swished or held against the affected area in the mouth/throat for a minute or two and then either expelled or swallowed as directed. The anesthetic effect begins within minutes and usually lasts on the order of 15–30 minutes, allowing procedures or swallowing without pain.

Precautions: Lidocaine oral solution should be used exactly as prescribed. Key precautions include avoiding excessive dose or swallowing large amounts, as lidocaine can be absorbed into the bloodstream and cause systemic toxicity (dizziness, hearing changes, slow heartbeat, seizures, etc.). Importantly, viscous lidocaine carries an FDA black-box warning in children: life-threatening events (seizures, cardiac arrest, death) have occurred in infants/young children (especially under 3 years old) when the product was misused or overdosed. Therefore, it is not recommended for use in babies or for infant teething pain, and it must be given in very limited doses in small children. The solution is contraindicated in anyone with a known allergy to lidocaine or other amide local anesthetics. Also be cautious if the mouth/throat mucosa is severely traumatized (risk of rapid absorption). Common side effects at proper doses are minimal, but overuse may cause numbness of the tongue, throat irritation, or drowsiness.

In summary, lidocaine oral solution is a prescription topical anesthetic for numbing painful mouth and throat lesions or for numbing during oral procedures (akin to a numbing mouthwash). It is effective for short-term relief of oral pain, but it requires careful dosing, especially in young children, and should only be used on the instructions of a healthcare provider.