Viscous lidocaine

Viscous lidocaine is a **topical anesthetic medication** used to **numb the mucous membranes** of the mouth and throat. It's commonly prescribed to **treat pain from mouth sores, irritation, or inflammation**, particularly in patients undergoing cancer chemotherapy or certain medical procedures. ## Composition and Formulation Viscous lidocaine typically comes as a **2% solution** (20 mg of lidocaine hydrochloride per mL) in a thick liquid form. The medication works by temporarily blocking nerve signals that cause pain, providing relief for conditions affecting the mouth and throat[1][2][4]. ## Usage Guidelines For mouth sores or irritation: - The solution should be **swished around the mouth** until pain subsides, then spit out - For adults, the typical dose is **15 mL** used no more than every 3 hours - Maximum of **8 doses** in a 24-hour period[1][2][6] For throat pain: - The solution should be **gargled** and may be swallowed or spit out - Same dosing restrictions apply as for mouth use[1][2][6] ## Important Warnings Viscous lidocaine carries **serious warnings**, particularly regarding use in children: - It may cause **serious side effects or death** in infants or children under 3 years of age if not used as recommended - It should **not be used to treat teething pain** in infants - In children under 3, it should only be used when prescribed by a doctor, with a maximum of **4 doses in 12 hours**[1][3][6][8] ## Side Effects Common side effects include: - Unusual or unpleasant taste in the mouth - Numbness in places where the medicine is accidentally applied[3] Serious side effects requiring immediate medical attention: - Drowsiness, depression, confusion, nervousness - Weakness, slow breathing, slow heart rate - Light-headedness or feeling faint - Numbness or cold feeling - Vomiting - Blurred vision[3][5] Viscous lidocaine can also cause **methemoglobinemia**, a serious blood disorder where red blood cells cannot deliver enough oxygen to the body. Risk factors include low glucose-6-phosphate dehydrogenase (G6PD), heart or lung problems, age 6 months or younger, and exposure to oxidizing agents[2]. Because the medication numbs the mouth and throat, it may affect swallowing ability. Patients should **avoid eating for at least 1 hour** after use and should **not chew gum** while using this medication[1][6].