Lidocaine

What it is

Lidocaine is an amide local anaesthetic, used as the hydrochloride salt. It comes as injections for local and regional anaesthesia, as an intravenous antiarrhythmic, and as topical gels, sprays, viscous oral solutions, creams and 5% patches. It is metabolised rapidly by the liver, with metabolites and unchanged drug excreted by the kidneys, so liver blood flow and liver function govern how long it lasts in the body.

What the research says

As a local anaesthetic it reliably blocks nerve conduction, and that use is not in dispute. Its other uses are weaker than their popularity suggests. For neuropathic pain, Cochrane found only very low quality (third tier) evidence that topical lidocaine beat placebo, and concluded there was no good-quality randomised evidence to support the use. Given prophylactically after a suspected heart attack, 37 trials in 11,948 people showed essentially no effect on death or ventricular fibrillation. In shock-refractory out-of-hospital cardiac arrest, the 3,026-patient ALPS trial found lidocaine did not significantly improve survival to discharge versus placebo. For perioperative intravenous infusion, Cochrane is uncertain whether it helps at all. Harms include methemoglobinemia, systemic toxicity with seizures (rare: 0.08 per 1,000 ultrasound-guided blocks) and, with the oral viscous solution in very young children, reported seizures, cardiopulmonary arrest and death.

Evidence grade: Disputed.

How it works

Drug class: Amide local anaesthetic; class Ib antiarrhythmic (sodium-channel blocker)

Lidocaine blocks the sodium channels that nerve and heart-muscle cells use to fire. By stopping the ion movements that start and carry an electrical impulse, it stops pain signals leaving the area it is applied to, and in the heart it damps abnormal electrical activity. The liver breaks it down quickly, and the kidneys excrete the products. (Source 1)

Boxed warning

Postmarketing cases of seizures, cardiopulmonary arrest, and death in patients under the age of 3 years have been reported with use of Lidocaine Viscous 2% when it was not administered in strict adherence to the dosing and administration recommendations. In the setting of teething pain, Lidocaine Viscous 2% should generally not be used. For other conditions, the use of the product in patients less than 3 years of age should be limited to those situations where safer alternatives are not available or have been tried but failed. To decrease the risk of serious adverse events with use of Lidocaine Viscous 2%, instruct caregivers to strictly adhere to the prescribed dose and frequency of administration and store the prescription bottle safely out of reach of children.

(Source 2)

What it is used for

• This is the approved use of the viscous 2% oral solution, with dosing capped by the label at not more than eight doses in 24 hours and a total dose not exceeding 4.5 mg/kg or 300 mg. The labelling for this product carries a prominent warning about life-threatening events in infants and young children. Evidence: established. (Source 2)
• Used routinely for peripheral regional anaesthesia. A prospective registry of 12,668 ultrasound-guided nerve blocks quantifies the harm side of this use: seizure from local anaesthetic systemic toxicity occurred at 0.08 per 1,000 blocks and there were no cardiac arrests, while persistent postoperative neurologic symptoms beyond 5 days occurred at 1.8 per 1,000. Evidence: established. (Source 3)
• Topical lidocaine, including the 5% patch, is used widely for postherpetic neuralgia and other neuropathic pain. A Cochrane review of 12 studies in 508 participants found only third-tier, very low quality evidence of benefit over placebo and concluded there was no good-quality randomised evidence to support the use, although individual studies indicated it relieved pain. Evidence: limited. (Source 4)
• In the 3,026-patient ALPS randomised trial, survival to hospital discharge was 23.7% with lidocaine versus 21.0% with placebo, a difference of 2.6 percentage points (95% CI -1.0 to 6.3; P = 0.16). Neither lidocaine nor amiodarone significantly improved survival or neurologic outcome over placebo. Evidence: not-supported. (Source 5)
• Once standard practice, now abandoned. A Cochrane review of 37 randomised trials in 11,948 participants found low-quality evidence that prophylactic lidocaine has very little or no effect on mortality (3.62% vs 3.40%; RR 1.02, 95% CI 0.82 to 1.27) or on ventricular fibrillation (1.48% vs 2.01%; RR 0.78, 95% CI 0.55 to 1.12). Evidence: not-supported. (Source 6)
• A Cochrane review of 68 trials in 4,525 participants reported a pooled standardised mean difference of -0.50 (95% CI -0.72 to -0.28) for pain at 1 to 4 hours but rated the evidence very low quality and stated the authors are uncertain whether it has any beneficial impact on early postoperative pain, gastrointestinal recovery, nausea or opioid use. Evidence: limited. (Source 7)

Interactions

• Other local anaesthetics and other drugs associated with methemoglobinemia (label): Giving lidocaine alongside another agent that can oxidise haemoglobin raises the risk of methemoglobinemia, in which the blood carries less oxygen. The label names other local anaesthetics - benzocaine, bupivacaine, prilocaine, tetracaine and others - among the co-exposures that increase this risk. (Source 8)
• Liver disease and anything that slows hepatic clearance (including age and debility) (label): Lidocaine is cleared rapidly by the liver, so reduced liver function or liver blood flow leaves more drug in circulation for longer, which is the route by which many interactions and toxicity occur. The label directs reduced doses for debilitated, elderly and acutely ill patients and for children. (Source 1)
• Repeated dosing within short intervals (self-limited by dose caps rather than a named interactant) (label): Cumulative dosing is the practical interaction that matters for the oral solution: exceeding the stated interval or daily number of doses raises blood levels toward the range where systemic toxicity occurs. (Source 9)

Stopping it

• Nothing in the literature read describes dependence, withdrawal or a rebound syndrome on stopping lidocaine in any of its forms. Where stopping has been studied as a question of practice, it is about abandoning a use that does not work: the Cochrane review of prophylactic lidocaine after myocardial infarction found low-quality evidence of very little or no effect on mortality or ventricular fibrillation. (Source 6)
• For the viscous oral solution in young children the labelling directs not starting or continuing it for teething pain, and restricting use under three years of age to cases where safer alternatives are unavailable or have failed. (Source 2)

What goes wrong

Seizures, cardiopulmonary arrest and death have been reported after use of viscous 2% lidocaine oral solution in children under three years old when it was not administered in strict adherence to the dosing and administration recommendations. (Source 2)

• Case series, Low certainty.
• Size: postmarketing case reports; number not stated on the label read.
• Who: Children under 3 years, including use for teething pain.
• How long: acute.
• Result: Seizures, cardiopulmonary arrest and death reported; the label advises the product generally not be used for teething pain and that use under age 3 be limited to situations where safer alternatives are unavailable or have failed.
• Funding: not applicable (regulatory postmarketing reports)

Postmarketing cases of seizures, cardiopulmonary arrest, and death in patients under the age of 3 years have been reported with use of Lidocaine Viscous 2% when it was not administered in strict adherence to the dosing and administration recommendations.

Local anaesthetics including lidocaine have been associated with methemoglobinemia, a condition in which the blood carries less oxygen; people with G6PD deficiency, congenital or idiopathic methemoglobinemia, cardiac or pulmonary compromise, infants under 6 months and those exposed to oxidizing agents are more susceptible. (Source 10)

• Official position, Low certainty.
• Size: not stated; postmarketing reports.
• Who: Patients given local anaesthetics, with higher risk when other methemoglobinemia-associated drugs are given at the same time.
• How long: acute, within hours of exposure.
• Result: No incidence rate given on the label read; the label states that signs may be delayed some hours after exposure, that methemoglobin levels may keep rising, and that immediate treatment is required.
• Funding: not applicable (regulatory position)

Cases of methemoglobinemia have been reported in association with local anesthetic use. Although all patients are at risk for methemoglobinemia, patients with glucose-6-phosphate dehydrogenase deficiency, congenital or idiopathic methemoglobinemia, cardiac or pulmonary compromise, infants under 6 months of age, and concurrent exposure to oxidizing agents or their metabolites are more susceptible to developing clinical manifestations of the condition. If local anesthetics must be used in these patients, close monitoring for symptoms and signs of methemoglobinemia is recommended.

Persistent postoperative neurologic symptoms occur after ultrasound-guided nerve blocks at a rate of roughly 2 per 1,000 beyond 5 days and 1 per 1,000 beyond 6 months. (Source 3)

• Cohort study, Moderate certainty.
• Size: 12,668 blocks.
• Who: Surgical patients having peripheral regional anaesthesia.
• How long: up to 6 months.
• Result: 1.8 per 1,000 (95% CI 1.1-2.7) for symptoms lasting longer than 5 days; 0.9 per 1,000 (95% CI 0.5-1.7) lasting longer than 6 months; 2.0 per 1,000 (95% CI 1.2-3.0) had unintended paresthesia during block placement.
• Funding: not stated.

In the setting of a surgical procedure, ultrasound-guided regional anesthesia is associated with the risk of long-term postoperative neurologic symptoms.

Whether perioperative intravenous lidocaine causes harm is unresolved because few trials systematically recorded adverse effects. (Source 7)

• Systematic review, Very low certainty.
• Size: 68 trials, 4,525 participants.
• Who: Adults having surgery.
• How long: perioperative.
• Result: Effect on adverse effects versus placebo uncertain; only a small number of studies systematically analysed adverse-effect occurrence (very low quality evidence)
• Funding: independent (Cochrane Anaesthesia)

The effect of IV lidocaine on adverse effects compared to placebo treatment is uncertain, as only a small number of studies systematically analysed the occurrence of adverse effects (very low-quality evidence).

In the Cochrane review of prophylactic lidocaine after myocardial infarction, lidocaine was associated with more asystole and more dizziness or drowsiness than placebo or no intervention, and the review judged its safety profile unclear because safety data were poorly reported. (Source 6)

• Systematic review, Very low certainty.
• Size: asystole: 4 studies, 6,826 participants; dizziness/drowsiness: 6 studies, 2,533 participants.
• Who: People with proven or suspected acute myocardial infarction given prophylactic lidocaine.
• How long: in-hospital and short-term follow-up.
• Result: Asystole 35/3393 (1.03%) vs 14/3443 (0.41%), RR 2.32 (95% CI 1.26 to 4.26), very low-quality evidence; dizziness/drowsiness 74/1259 (5.88%) vs 16/1274 (1.26%), RR 3.85 (95% CI 2.29 to 6.47), low-quality evidence.
• Funding: independent (Cochrane Heart Group)

Lidocaine compared with placebo or no intervention increased risk of asystole (35/3393 (1.03%) vs 14/3443 (0.41%); RR 2.32, 95% CI 1.26 to 4.26; participants = 6826; studies = 4; I(2) = 0%; very low-quality evidence) and dizziness/drowsiness (74/1259 (5.88%) vs 16/1274 (1.26%); RR 3.85, 95% CI 2.29 to 6.47; participants = 2533; studies = 6; I(2) = 0%; low-quality evidence). Overall, safety data were poorly reported and adverse events may have been underestimated.

What the evidence supports

Serious systemic toxicity from local anaesthetic during ultrasound-guided nerve blocks is rare, at well under one seizure per thousand blocks. (Source 3)

• Cohort study, Moderate certainty.
• Size: 12,668 ultrasound-guided nerve blocks.
• Who: Patients undergoing peripheral regional anaesthesia at one academic medical centre.
• How long: prospective registry, perioperative and up to 6 months for neurologic symptoms.
• Result: Seizure 0.08 per 1,000 blocks (95% CI 0.0-0.3); no cardiac arrests; unintended venous puncture 0.6 per 1,000 (95% CI 0.2-1.2)
• Funding: not stated.

Local anesthetic systemic toxicity, however, is extremely uncommon.

Topical lidocaine was better than placebo for pain relief in individual neuropathic pain studies, but only on very low quality evidence. (Source 4)

• Systematic review, Very low certainty.
• Size: 12 studies, 508 participants.
• Who: Adults with neuropathic pain, mostly postherpetic neuralgia.
• How long: varied; many studies short and with incomplete outcome assessment.
• Result: Third tier (very low quality) evidence of benefit in all but one study; no first or second tier evidence available, all studies at high risk of bias through small size or incomplete outcome assessment.
• Funding: independent (Cochrane Pain, Palliative and Supportive Care)

In all but one study, third tier (very low quality) evidence indicated that lidocaine was better than placebo for some measure of pain relief.

What the evidence does not support

Cochrane found no good-quality randomised evidence supporting topical lidocaine for neuropathic pain. (Source 4)

• Systematic review, Very low certainty.
• Size: 12 studies, 508 participants.
• Who: Adults with neuropathic pain.
• How long: varied.
• Result: No first or second tier evidence; all included studies at high risk of bias.
• Funding: independent (Cochrane)

This review found no evidence from good quality randomised controlled studies to support the use of topical lidocaine to treat neuropathic pain, although individual studies indicated that it was effective for relief of pain.

Prophylactic lidocaine after acute myocardial infarction has very little or no effect on death or ventricular fibrillation, on low-quality evidence from trials at high risk of bias; the review judged its safety profile unclear. (Source 6)

• Systematic review, Low certainty.
• Size: 37 randomised controlled trials, 11,948 participants.
• Who: People with proven or suspected acute myocardial infarction.
• How long: in-hospital and short-term follow-up.
• Result: All-cause mortality 213/5,879 (3.62%) with lidocaine vs 199/5,848 (3.40%) control, RR 1.02 (95% CI 0.82 to 1.27); ventricular fibrillation 76/5,128 (1.48%) vs 103/4,987 (2.01%), RR 0.78 (95% CI 0.55 to 1.12). Absolute difference in mortality 0.22 percentage points against lidocaine.
• Funding: independent (Cochrane Heart Group)

This Cochrane review found evidence of low quality to suggest that prophylactic lidocaine has very little or no effect on mortality or ventricular fibrillation in people with acute myocardial infarction. The safety profile is unclear. This conclusion is based on randomised controlled trials with high risk of bias.

In shock-refractory out-of-hospital cardiac arrest, lidocaine did not significantly improve survival to hospital discharge compared with placebo. (Source 5)

• Randomized trial, High certainty.
• Size: 3,026 patients (amiodarone 974, lidocaine 993, placebo 1,059)
• Who: Adults with out-of-hospital cardiac arrest and shock-refractory ventricular fibrillation or pulseless ventricular tachycardia.
• How long: to hospital discharge.
• Result: Survival to discharge 24.4% amiodarone, 23.7% lidocaine, 21.0% placebo; lidocaine versus placebo 2.6 percentage points (95% CI -1.0 to 6.3; P = 0.16), i.e. an absolute difference that could not be distinguished from zero; per-protocol population; heterogeneity of treatment effect by whether the arrest was witnessed (P=0.05), with active drugs better than placebo in bystander-witnessed arrest but not unwitnessed arrest.
• Funding: not stated in the record read; conducted by the NIH-supported Resuscitation Outcomes Consortium.

Overall, neither amiodarone nor lidocaine resulted in a significantly higher rate of survival or favorable neurologic outcome than the rate with placebo among patients with out-of-hospital cardiac arrest due to initial shock-refractory ventricular fibrillation or pulseless ventricular tachycardia.

Cochrane is uncertain whether perioperative intravenous lidocaine improves early postoperative pain, bowel recovery, nausea or opioid use, and judged that lidocaine probably has no clinically relevant effect on pain scores later than 24 hours. (Source 7)

• Systematic review, Very low certainty.
• Size: 68 trials, 4,525 randomised participants.
• Who: Adults having surgery under general anaesthesia.
• How long: early postoperative period (1 to 4 hours) and recovery.
• Result: Pain at 1 to 4 hours SMD -0.50 (95% CI -0.72 to -0.28) from 29 studies and 1,656 participants, rated very low quality; conclusions uncertain for pain, gastrointestinal recovery, nausea and opioid consumption.
• Funding: independent (Cochrane Anaesthesia)

We are uncertain whether IV perioperative lidocaine, when compared to placebo or no treatment, has a beneficial impact on pain scores in the early postoperative phase, and on gastrointestinal recovery, postoperative nausea, and opioid consumption. The quality of evidence was limited due to inconsistency, imprecision, and study quality. Lidocaine probably has no clinically relevant effect on pain scores later than 24 hours.

Where the research disagrees

Whether topical lidocaine works for neuropathic pain

• Derry et al 2014, Cochrane, systematic review of 12 studies, 508 participants, all at high risk of bias; very low quality (third tier) evidence: This review found no evidence from good quality randomised controlled studies to support the use of topical lidocaine to treat neuropathic pain, although individual studies indicated that it was effective for relief of pain. (Source 4)

Whether antiarrhythmic lidocaine improves survival in cardiac arrest

• ALPS trial investigators 2016, randomised, placebo-controlled trial, 3,026 patients: Overall, neither amiodarone nor lidocaine resulted in a significantly higher rate of survival or favorable neurologic outcome than the rate with placebo among patients with out-of-hospital cardiac arrest due to initial shock-refractory ventricular fibrillation or pulseless ventricular tachycardia. (Source 5)
• Martí-Carvajal et al 2015, Cochrane (prophylactic use after myocardial infarction), systematic review of 37 randomised trials, 11,948 participants: This Cochrane review found evidence of low quality to suggest that prophylactic lidocaine has very little or no effect on mortality or ventricular fibrillation in people with acute myocardial infarction. The safety profile is unclear. This conclusion is based on randomised controlled trials with high risk of bias. (Source 6)

How much

• Reference intake: Dosing is set by the prescriber and by the route used, not by the reader. As a position, the US prescribing information for lidocaine viscous 2% states that for symptomatic treatment of irritated or inflamed mucous membranes of the mouth and pharynx the usual adult dose is 15 mL undiluted, not repeated at intervals shorter than three hours. (Source 9)
• Upper limit: The label's stated ceilings for the viscous oral solution are not more than eight doses in any 24-hour period and a dose not exceeding 4.5 mg/kg (2 mg/lb) body weight, and in no case exceeding a total of 300 mg; it also directs reduced doses for debilitated, elderly or acutely ill patients and children. There is no reference intake or upper intake level, because lidocaine is a drug and not a nutrient. (Source 9)
• Studied: The ALPS trial gave lidocaine, amiodarone or placebo intravenously during out-of-hospital cardiac arrest to 3,026 patients; mg doses are not stated in the record read. (Source 5)
• Studied: The Cochrane review of prophylaxis after myocardial infarction pooled 37 trials and 11,948 participants given lidocaine versus placebo or no intervention; regimens varied across trials. (Source 6)
• Studied: The Cochrane review of perioperative intravenous lidocaine pooled 68 trials and 4,525 participants given continuous infusions starting around the time of surgery. (Source 7)
• Studied: The Cochrane review of topical lidocaine pooled 12 studies and 508 participants, mostly using the 5% medicated plaster or topical gels for neuropathic pain. (Source 4)

A common belief, and what the research shows

The belief: Lidocaine is one of the safest drugs there is - it is only a numbing agent, and a lidocaine patch or gel is a gentle way to treat nerve pain.

What the research shows: Its anaesthetic action is real and its systemic toxicity is genuinely rare: 0.08 seizures per 1,000 ultrasound-guided nerve blocks, with no cardiac arrests in 12,668 blocks. But 'safe' and 'effective for nerve pain' are different claims. Cochrane found only third-tier, very low quality evidence that topical lidocaine beat placebo for neuropathic pain and concluded there was no good-quality randomised evidence supporting the use. And it is not harmless: viscous 2% oral lidocaine has been linked in postmarketing reports to seizures, cardiopulmonary arrest and death in children under three, methemoglobinemia is a recognised risk that can progress to seizures, coma and arrhythmias, and roughly 1 in 1,000 nerve blocks is followed by neurologic symptoms lasting beyond six months.

Questions and answers

What is it?

Lidocaine, also spelled lignocaine, is a man-made local anaesthetic in the amide family. The same molecule is used as an injection to numb tissue, as an intravenous drug for abnormal heart rhythms, and as gels, sprays, viscous mouth solutions, creams and 5% skin patches. The liver breaks it down quickly and the kidneys clear the products. (Source 1)

What does it do in the body?

It blocks the electrical signalling of nerve cells, so the nerves in the treated area stop sending pain messages. In the heart the same action damps abnormal rhythms, which is why it is also used as an antiarrhythmic. The effect is local and temporary, wearing off as the drug is cleared. (Source 1)

Is it good or bad for you?

Good for what it was designed to do, weak for most of what it is hoped to do, and genuinely dangerous in a few settings. As an anaesthetic it works and serious systemic toxicity is rare. For nerve pain, Cochrane found no good-quality evidence of benefit. In children under three the viscous oral solution has been linked to seizures, cardiopulmonary arrest and death, and in cardiac arrest it did not significantly improve survival. (Source 3)

How do you get more of it?

Does not apply: lidocaine is a drug, not a nutrient, and nothing you eat or do supplies it. How much a person receives is set by their clinician and by the product label; for the viscous oral solution the label caps dosing at intervals of no less than three hours and no more than eight doses in 24 hours. That is recorded here as the label's position, not as advice. (Source 9)

If it is harmful, what reduces it?

The body clears lidocaine itself: the liver metabolises it rapidly and the kidneys excrete it, so stopping the drug ends the exposure within hours in people with normal liver function. Where it has caused methemoglobinemia, the label states that levels may keep climbing and that immediate treatment is required rather than waiting for clearance. (Source 10)

Why might someone be low in it or missing it?

Does not apply: nobody can be low in or deficient in lidocaine. A person has none unless it is given. The reasons a clinician would give less of it are safety ones - the label directs reduced doses for debilitated, elderly and acutely ill patients and for children, and generally avoiding the viscous oral solution for teething pain. (Source 8)

Which whole foods contain it or feed it?

No whole food contains lidocaine; it is entirely synthetic. The food-related issue in the labelling is the reverse one: the viscous oral solution numbs the mouth and throat, which is why its use around eating and in young children is restricted, with reported seizures, cardiopulmonary arrest and death in the under-threes. (Source 2)

What happens if you do not have it?

Nothing happens physiologically from not having lidocaine, because there is no deficiency state. What is forgone is procedural comfort: without a local anaesthetic, procedures that nerve blocks make tolerable would be done unanaesthetised. For the uses where the evidence is weak, little appears to be forgone - in shock-refractory cardiac arrest, survival to discharge was 23.7% with lidocaine and 21.0% with placebo, a difference that was not statistically significant. (Source 5)

How can you test for it?

There is no test for lidocaine status, and blood lidocaine levels are not routinely measured outside specialist settings. What is tested for is its complications: methemoglobin level when methemoglobinemia is suspected, since the label notes levels can keep rising and demand immediate treatment. No validated test tells a person whether they need lidocaine. (Source 10)

We searched: Searched for lidocaine therapeutic drug monitoring and validated tests of lidocaine status alongside the Cochrane reviews of topical and intravenous lidocaine, the ALPS trial and the lidocaine viscous prescribing information; none described a test of need or status, only methemoglobin measurement in suspected toxicity.

References

1. DailyMed (US National Library of Medicine), SPL set ID 79b42076-359d-4258-b1d8-f40e67ac5424; label revised May 2023, DailyMed version December 2024. Lidocaine Hydrochloride Oral Topical Solution USP 2% (Lidocaine Viscous) - US prescribing information (labeler: Hikma Pharmaceuticals USA Inc.), Clinical Pharmacology. 2023. Read the source
2. DailyMed (US National Library of Medicine), SPL set ID 79b42076-359d-4258-b1d8-f40e67ac5424; label revised May 2023, DailyMed version December 2024. Lidocaine Hydrochloride Oral Topical Solution USP 2% (Lidocaine Viscous) - US prescribing information (labeler: Hikma Pharmaceuticals USA Inc.), Boxed Warning. 2023. Read the source
3. Regional Anesthesia and Pain Medicine. Incidence of Local Anesthetic Systemic Toxicity and Postoperative Neurologic Symptoms Associated With 12,668 Ultrasound-Guided Nerve Blocks: An Analysis From a Prospective Clinical Registry. 2012. PMID 22705953, DOI 10.1097/AAP.0b013e31825cb3d6. Read the source
4. Cochrane Database of Systematic Reviews. Topical lidocaine for neuropathic pain in adults. 2014. PMID 25058164, DOI 10.1002/14651858.CD010958.pub2. Read the source
5. New England Journal of Medicine. Amiodarone, lidocaine, or placebo in out-of-hospital cardiac arrest. 2016. PMID 27043165, DOI 10.1056/NEJMoa1514204. Read the source
6. Cochrane Database of Systematic Reviews. Prophylactic lidocaine for myocardial infarction. 2015. PMID 26295202, DOI 10.1002/14651858.CD008553.pub2. Read the source
7. Cochrane Database of Systematic Reviews. Continuous intravenous perioperative lidocaine infusion for postoperative pain and recovery in adults. 2018. PMID 29864216, DOI 10.1002/14651858.CD009642.pub3. Read the source
8. DailyMed (US National Library of Medicine), SPL set ID 79b42076-359d-4258-b1d8-f40e67ac5424; label revised May 2023, DailyMed version December 2024. Lidocaine Hydrochloride Oral Topical Solution USP 2% (Lidocaine Viscous) - US prescribing information (labeler: Hikma Pharmaceuticals USA Inc.), Precautions (General) and Drug Interactions. 2023. Read the source
9. DailyMed (US National Library of Medicine), SPL set ID 79b42076-359d-4258-b1d8-f40e67ac5424; label revised May 2023, DailyMed version December 2024. Lidocaine Hydrochloride Oral Topical Solution USP 2% (Lidocaine Viscous) - US prescribing information (labeler: Hikma Pharmaceuticals USA Inc.), Dosage and Administration (Adult). 2023. Read the source
10. DailyMed (US National Library of Medicine), SPL set ID 79b42076-359d-4258-b1d8-f40e67ac5424; label revised May 2023, DailyMed version December 2024. Lidocaine Hydrochloride Oral Topical Solution USP 2% (Lidocaine Viscous) - US prescribing information (labeler: Hikma Pharmaceuticals USA Inc.), Warnings. 2023. Read the source