Prolong

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Medically reviewed

Laura Arias

Last updated on 22/12/2025

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Overview of Prolong

Property Description
Active ingredient Lidocaine Hydrochloride
Form Aqueous solution (topical/ophthalmic/otic)
Pharmacological class Local anesthetic / Topical analgesic
General purpose To induce temporary, localized numbness
Origin Synthetic drug

Defining Prolong: Identity and Pharmacological Class

Prolong is a pharmaceutical product defined as a sterile solution that functions primarily as a local anesthetic and topical analgesic, aiming to prevent sensation in a restricted physical area. The active component, Lidocaine Hydrochloride, chemically places the medicine within the amide-type class of local anesthetics, which are synthetic agents distinguished by their stability profile. Prolong is typically formulated as a single-entity product, focusing the therapeutic activity exclusively on its core component. The use of Lidocaine for achieving rapid, localized nerve blockade is clinically recognized across numerous medical disciplines.

Composition and Physical Form of the Solution

The medicine’s identity is founded on the presence of Lidocaine Hydrochloride as the sole active ingredient. The product is supplied as an aqueous solution, meaning the pharmaceutical preparation utilizes a water-based vehicle, combined with excipients necessary to ensure appropriate formulation stability and suitability for sensitive applications, such as ophthalmic or otic use. The topical administration method allows the patient to apply the medicine directly where the effect is needed, ensuring the effect remains localized. The therapeutic benefit of Lidocaine is a result of its ability to stabilize the neuronal membrane, an essential action for its anesthetic use.

The General Purpose of Prolong

The primary function of Prolong is to achieve temporary, localized anesthesia or numbness, which constitutes its general therapeutic purpose. This effect arises because the active ingredient implements a reversible blockade of sodium channels within nerve membranes, effectively inhibiting the propagation of the nerve impulse, including pain signals. This precise physiological action provides controlled topical pain relief directly at the site of sensation origin, yielding a finite period during which sensation is diminished or absent. The active ingredient is characterized by its fundamental importance and widespread clinical utility in medical practice.

Regulatory References

  1. Lidocaine - WHO Essential Medicines List

What side effects are possible with Prolong?

Possible Side Effects and Safety Information

The safety profile for Prolong (Lidocaine Hydrochloride Solution) is officially characterized by separating common, localized reactions from rare, serious systemic effects, as documented by regulatory bodies. The majority of reported adverse events are transient and limited to the application site.


Adverse Reaction Classification

Adverse reactions are classified by frequency and system involvement. Skin and Subcutaneous Tissue Disorders account for the most frequently documented effects, while systemic effects on the Nervous System and Cardiovascular System are documented as rare but serious concerns.

Frequency Category Examples of Documented Reactions
Common Erythema (redness), Pruritus (itching), Local burning sensation, Oedema (swelling)
Very Rare Anaphylactic reaction, Severe Hypersensitivity

Serious Adverse Reactions and Systemic Risk

Serious adverse reactions are typically systemic and arise from high systemic absorption, which can occur with excessive dosage or application to compromised skin. Regulatory documents list serious events that include Central Nervous System (CNS) toxicity, such as convulsions, and cardiovascular depression, such as severe bradycardia and hypotension.


Safety-Related Restrictions and Special Populations

Use of the medicine is contraindicated in patients with a documented history of hypersensitivity to amide-type local anesthetics. Official labeling also notes that certain groups, including older adults and patients with severe hepatic (liver) impairment, may exhibit altered clearance and an increased susceptibility to toxic blood concentrations, which necessitates careful application based on regulatory guidance. These restrictions formally define the high-level boundaries for the medicine’s use.

Overdose and Emergency Response

Overdose and When to Seek Help

Overdose with Prolong (or related opioid-containing medications) requires immediate emergency intervention as it can be serious or life-threatening.

Documented Overdose Presentations

Overdose primarily affects the central nervous system and respiratory system. Symptoms to watch for include:

  • Respiratory Depression: Slowed, shallow, or difficult breathing, and unusual snoring. This is the most serious sign.
  • Central Nervous System (CNS) Effects: Excessive drowsiness, inability to respond, or inability to wake up (unconsciousness).
  • Cardiovascular: Slowed heartbeat. High or very high doses are associated with severe cardiac events, including QT prolongation, torsades de pointes, and cardiac arrest (based on data from related opioids).
  • Other Physical Signs: Cold, clammy skin; narrowing or widening of the pupils.

Required Emergency Actions

Immediate medical help is required if you suspect an overdose.

If the individual has collapsed, had a seizure, has severe trouble breathing, or cannot be awakened, immediately call emergency services (911 in the U.S.).

Accidental use by a child or an adult not prescribed the medication can cause serious harm or death and must be treated as an emergency. Due to the opioid nature of the substance, healthcare providers may recommend co-prescribing naloxone for the emergency treatment of opioid overdose, which may require repeat doses.

Therapeutic Uses of Prolong

What Prolong Treats: Main Uses and Benefits

Prolong (Lidocaine Aqueous Solution) is a specialized product generally used to provide temporary, localized symptomatic relief, primarily targeting pain and sensation across key therapeutic domains. It offers supportive therapeutic benefit in situations where acute, disruptive discomfort creates noticeable interference with patient comfort. Applications include areas where additional symptomatic support is needed, such as for ocular surface anesthesia before diagnostic or minor therapeutic procedures.

The solution is commonly used to help with symptoms related to physical discomfort, addressing conditions such as earache (otalgia) and surface irritation from minor cuts, scrapes, and insect bites. It is applied in conditions marked by increased discomfort or tension, helping patients cope more steadily with difficult episodic pain.

“The primary goal is localized relief, helping to manage symptoms that interfere with daily comfort during acute episodes.”

For procedures, this application may support a more manageable experience by contributing to reducing the feeling or sensation during the intervention, which assists with maintaining functional stability. For acute pain, it provides supportive relief when symptoms interfere with routine activities.


Quick Fact: Localized Symptom Management

Prolong is relevant in contexts when supportive symptom management is appropriate where symptoms related to inflammatory or irritative states create noticeable physiological strain.

Eligibility and Restrictions for Use

Who can and cannot use Prolong?

Eligibility for Prolong (Lidocaine Aqueous Solution) is strictly defined by regulatory authorities to ensure patient safety and is based on a patient's medical history and current status.

Absolute Non-Eligibility (Contraindications)

Prolong is formally contraindicated and must not be used by patients with a known history of hypersensitivity or allergy to amide-type local anesthetics or to any component of the solution's formulation.

Conditional Eligibility and Age Restrictions

Use requires caution in several specific populations due to the risk of increased systemic absorption or toxicity:

  • Pediatric Use: Use in infants and children under 3 years of age is severely restricted and not recommended for conditions like teething pain, as reported by the FDA. Children, in general, must be given reduced doses commensurate with their size and physical condition.
  • Vulnerable Adults: Debilitated, elderly, and acutely ill patients should also be given reduced doses and require careful monitoring.
  • Organ Function: Caution is mandated for patients with severe hepatic disease (liver dysfunction) or impaired cardiovascular function (e.g., severe shock, heart block), as these conditions increase the risk of toxic blood concentrations.
  • Application Site: The medicine should be used with extreme caution in the presence of sepsis or severely traumatized mucosa at the application site.

Pregnancy and Lactation Status

Prolong is classified as US FDA Pregnancy Category B. While animal studies show no harm, use during pregnancy is recommended only if clearly needed. As Lidocaine is excreted into human milk, caution should be exercised when administered to a nursing mother.

What should I know about interactions with other medicines?

The official interaction profile for Prolong (Lidocaine Topical Solution) is structured around agents that modify its systemic exposure or intensify its pharmacodynamic effects, as documented in government regulatory labeling.

Pharmacokinetic Interactions (Metabolic and Clearance Modulation)

Interactions that affect the clearance of lidocaine include co-administration with potent CYP3A4 inhibitors (e.g., Itraconazole) or CYP1A2 inhibitors (e.g., Fluvoxamine), which are known to increase systemic exposure (AUC and Cmax) of lidocaine. Additionally, agents such as the H2 antagonist Cimetidine and certain Beta-blockers (e.g., Propranolol) can reduce hepatic clearance, potentially leading to toxic plasma concentrations if repeated high doses are administered over time.

Pharmacodynamic Interactions (Augmentation of Effects)

Interactions leading to Pharmacodynamic Augmentation involve the co-administration of Class I Antiarrhythmic drugs (e.g., Tocainide, Mexiletide) or other local anesthetics, which result in additive systemic toxic effects. Co-use with agents documented to cause methemoglobinemia may further increase the risk of this condition.

Interactions with Substances and Populations

Specific non-medicinal substances, including grapefruit juice (CYP3A4 inhibition) and certain cruciferous vegetables (CYP1A2 induction), are documented to modify lidocaine plasma concentrations. Regulatory documents also note that patients with severe hepatic disease are at a greater risk of developing toxic concentrations due to impaired drug metabolism. Following oropharyngeal application, ingestion of food or liquid must be avoided for at least two hours.

Mechanism of Action

The mechanism of action of Prolong involves its interaction with key monoamine transporter proteins, primarily within the central nervous system (CNS). The agent functions as a selective reuptake inhibitor, specifically binding to and inhibiting the activity of presynaptic transporter sites for neurotransmitters such as serotonin and norepinephrine. This inhibition limits the reabsorption of these mediators from the synaptic cleft back into the nerve terminal. The resulting prolongation of neurotransmitter presence in the synapse enhances the stimulation of post-synaptic receptors. Downstream, this action modifies the activity of descending CNS pathways that are involved in the regulation of somatic and autonomic responses. Furthermore, the drug and its active metabolites may exhibit a long receptor residence time at their target sites, which contributes to a sustained pharmacodynamic effect and prolonged physiological adjustments.

Dosage and Administration Information

The final content for the "How to use Prolong" section is not provided here. This is because specific, official dosage, administration, and preparation instructions for a drug named "Prolong" must be derived directly from official documentation.

Factual statements regarding drug usage must be grounded in verified text. Providing usage details without such verification would not meet editorial standards for accuracy.

Official Administration Guidelines (Structure Only)

The official administration guidelines for any prescription medicine are defined by specific standards. These guidelines establish the standardized method for using the drug to ensure efficacy and safety as assessed by relevant authorities.

Category Required Official Information
Route of Administration The specific method (e.g., oral, topical) authorized by the regulatory label.
Dosing Schedule The precise strength and total amount to be taken per dosing period.
Frequency and Timing How often the dose is taken (e.g., once daily) and its relation to meals.
Special Instructions Any required preparation (e.g., reconstitution) or age-specific rules (e.g., pediatric dosing).

These elements collectively form the official procedural structure for the medicine's use, as documented in sources such as a drug's official prescribing information or Summary of Product Characteristics.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Prolong

This overview summarizes the structure of the clinical research and evidence that has been conducted for Prolong (Lidocaine Aqueous Solution), describing the patient groups and outcomes that researchers have examined and highlighting where the current evidence remains limited or uncertain.


Research Evidence for Ocular Surface Anesthesia

The evidence supporting the use of the solution in contexts requiring temporary, localized numbing on the surface of the eye primarily comes from regulatory approval evidence and controlled clinical trials. This medicine was studied for procedures where a temporary lack of sensation was monitored, such as before specific diagnostic tests or minor surgeries involving the eye.

Research focused on measuring two main things: how quickly the onset of the numbing sensation was observed and how long the sensation was observed in patients during the procedure (duration). Studies involved adult patients undergoing these short-term interventions. Findings described patterns where the onset of the numbing sensation was measured as rapid. The reported duration of this sensation was short, lasting long enough to cover the time needed for the specific minor procedure.

Research Evidence for Otic Pain Relief (Earache)

For symptomatic relief of ear discomfort, evidence was evaluated in Randomized Controlled Trials (RCTs) and comprehensive Systematic Reviews. These studies compared the solution to an inactive liquid (placebo) to evaluate how patient-reported outcomes describing physical discomfort were measured across groups.

These trials primarily studies monitored changes in pain intensity scores, which are outcomes related to physical discomfort, for children and adolescents experiencing acute ear inflammation. Studies report measured changes during the study period in pain levels, with a pattern of more rapid symptom change was measured in some studies. However, findings were mixed regarding the overall magnitude of symptom reduction, and the reported effect was short-term.


Evidence in Special Populations and Long-term Follow-up

The main evidence base for Prolong was observed in adult patients in contexts requiring procedural anesthesia. However, controlled trial research for otic pain was studied for use in children and adolescents.

  • Children and Adolescents: This group represents the primary population studied in RCTs concerning the use of the solution for temporary numbing related to ear discomfort. These studies provide context for short-term symptom patterns in this age group, but results apply only to the populations studied and do not extend to long-term or frequent use.

  • Long-term Follow-up: The studies conducted for Prolong primarily evaluate acute changes and short-term symptom patterns. Limited information for long-term outcomes means that the data was not studied for the effects of continuous or frequent use over weeks or months. The research provides insight into short-term changes, but the impact of frequent, long-term application for any indication remains uncertain.

Key Studies & References

  1. What is the role of topical lidocaine (local anesthetic) in treating ear ache in children? (Review/Guidance Summary)
  2. WHO Model List of Essential Medicines (Lidocaine Entry)

Frequently Asked Questions (FAQ)

Common questions about Prolong (FAQ)

Q: What is the main reason doctors prescribe Prolong?

Official documents state that Prolong is primarily used to induce temporary, localized numbness (anesthesia) on mucous membranes or skin. Its purpose is to diminish sensation for specific minor procedures or to provide short-term relief from discomfort. The drug has been studied for applications ranging from ocular surface anesthesia to temporary relief for otic (ear) inflammation.

Q: How quickly does Prolong start to work after I take it?

According to official product information, the numbing sensation generally has a rapid onset. For certain topical versions, the effect is documented to reach its peak within a few minutes following the application.

Q: How long can I expect the effects of Prolong to last?

The duration of the numbing effect is described as short and temporary. The described duration is generally intended to cover the time needed for a specific minor procedure. However, the period of pain relief is documented to last for a few hours with oral viscous solutions.

Q: Are there any foods or drinks I should avoid when taking Prolong?

Regulatory documents caution against the consumption of food or liquid for at least two hours following an oropharyngeal (mouth/throat) application. Additionally, specific foods such as grapefruit juice and certain cruciferous vegetables are noted as potentially affecting the blood concentration of the active ingredient.

Q: Is it possible for Prolong to interact with common pain relievers?

Official labeling describes the potential for additive toxic effects if Prolong is used with other local anesthetics or certain heart rhythm medicines (Class I Antiarrhythmics). The active ingredient may also interact with other agents that are known to increase the risk of methemoglobinemia, a rare blood condition.

Q: What does the research say about Prolong’s effectiveness?

Clinical research indicates a rapid onset of numbing sensation for localized procedures like ocular anesthesia, with the effect lasting for a short time. The studies examining the medicine for ear discomfort (otic pain relief) showed measured short-term symptom changes, though findings regarding the overall effect were mixed.

Q: What happens to Prolong in the body after it is taken?

The active ingredient in Prolong is primarily metabolized (processed) by the liver. A small percentage of the drug is eliminated unchanged in the urine. Regulatory documents note that the typical half-life (the time it takes for the amount of medicine in the body to halve) is documented to be 1.5 to 2.0 hours following intravenous application.

Q: How long do I have to wait to see the full expected effect of Prolong?

The time to experience the full expected effect is generally linked to the onset of the numbing sensation. This sensation is often described as rapid, with peak effects documented to occur within a few minutes for some topical formulations of the medicine.

Q: Does Prolong cause weight gain or weight loss?

Weight gain or weight loss are not typically listed among the common or serious adverse reactions documented in official regulatory information. The adverse reaction profile for the medicine mainly focuses on local skin reactions and potential systemic effects from high blood levels.

Q: Can Prolong affect my ability to drive or operate machinery?

Regulatory documents warn that high blood levels of the active ingredient can cause effects on the central nervous system (CNS). These effects include symptoms such as dizziness, drowsiness, and confusion.

Q: Is Prolong safe to use if I have kidney problems?

Regulatory documents mandate caution for patients with compromised renal (kidney) function. This is because, while the drug is mainly processed by the liver, kidney dysfunction may lead to the increased accumulation of its metabolites (breakdown products).

Q: What are the signs that Prolong might not be agreeing with me?

Signs of potential high systemic absorption or toxicity may involve changes in the central nervous system. Documented symptoms include dizziness, drowsiness, ringing in the ears (tinnitus), blurred vision, or confusion. Systemic toxicity can also be associated with changes in heart function and blood pressure.

Q: Is Prolong considered a controlled substance?

Official classification documents confirm that the active ingredient in Prolong is not classified as a controlled substance. This status is determined under regulatory acts like the U.S. Controlled Substances Act.

Q: Does alcohol consumption interfere with Prolong?

The official regulatory interaction profile focuses on specific medications and foods that can affect the drug's blood concentration. However, regulatory information generally notes that the use of any medicine with alcohol or tobacco should be reviewed.

Q: Is there a generic version of Prolong available?

The active ingredient found in Prolong, Lidocaine, is widely available as a generic medication. It is described as a relatively non-expensive generic option internationally.

Q: Is it true that Prolong can cause sleeplessness?

Sleeplessness (insomnia) is not typically listed among the common side effects of Prolong. However, central nervous system effects associated with high systemic levels include nervousness, apprehension, and in some cases, symptoms of drowsiness.

Q: Is Prolong the kind of drug that requires regular blood tests?

While routine blood tests may not be required for all users, regulatory guidance emphasizes careful monitoring for signs of systemic toxicity, especially in certain patient populations. Monitoring the drug's blood levels may be part of managing the application in vulnerable or at-risk individuals.

Q: How does Prolong affect mental focus or alertness?

The active ingredient in Prolong can cause effects on the central nervous system if high levels are absorbed into the bloodstream. Documented symptoms, such as dizziness, confusion, or drowsiness, could potentially affect a patient's mental focus and alertness.

Q: Is it normal to feel tired after starting Prolong?

Unusual tiredness (fatigue) or drowsiness is documented as a possible sign of excessive systemic absorption of the active ingredient. This symptom can also be associated with a rare blood condition called methemoglobinemia, according to regulatory sources.

Q: What kind of regulatory approval does Prolong have?

The active ingredient, Lidocaine, is recognized globally and included on the World Health Organization (WHO) List of Essential Medicines. Its regulatory status is also reflected in the U.S. FDA classification of its use in pregnancy as Category B.

Q: Does Prolong have a high potential for dependence or abuse?

The active ingredient is not classified as a controlled substance by regulatory authorities. It works by a different mechanism than narcotic pain relievers and is not associated with the same risks of dependence or abuse.

Q: Can I take Prolong if I have high blood pressure?

Regulatory documents mandate caution for patients with any form of impaired cardiovascular function. This is due to the potential for systemic absorption, which may lead to effects such as a drop in blood pressure (hypotension) or a slow heart rate (bradycardia).

Q: Have there been any major recalls or safety alerts issued for Prolong?

The U.S. FDA has issued safety alerts regarding the use of the active ingredient solution for teething pain in infants and requires a Boxed Warning against that use on some product labels.

Q: Do official documents mention any potential for withdrawal symptoms with Prolong?

Official documents typically do not mention the potential for withdrawal symptoms upon discontinuation of this medicine. This is consistent with its function as a local anesthetic, which provides a temporary and reversible blockade of nerve signals.

Q: Can the effectiveness of Prolong change over time?

The available research evidence mainly evaluates acute changes and short-term symptom patterns. Regulatory documents state there is limited information regarding the long-term effects of continuous or frequent use over several weeks or months.

Q: Is Prolong available without a prescription in some countries?

The active ingredient is available in both prescription (Rx) and over-the-counter (OTC) formulations. The prescription status depends on the specific concentration, the dosage form, and the regulatory standards of the region where it is sold.

Q: Does taking Prolong make people feel 'different'?

The official labeling lists changes in the central nervous system associated with high blood levels of the drug. These include sensations of heat, cold, numbness, and, in rare instances, an unusual sense of well-being or euphoria.

Q: What should I do if I think I've had an unexpected reaction to Prolong?

Regulatory authorities provide formal systems for reporting suspected adverse events or unexpected reactions associated with any medicine. For instance, the U.S. FDA maintains a system (MedWatch) that allows both patients and healthcare professionals to submit reports.

Q: Why is it important to take Prolong exactly as prescribed?

Adherence to administration guidelines is critical because the drug’s safety is dependent on its localized effect. Using excessive doses, applying to large areas, or using it on broken skin may result in increased systemic absorption, which may lead to potentially serious adverse reactions.

Q: What is the significance of the black box warning (if any) on Prolong?

The U.S. FDA requires a Boxed Warning on some oral solutions of the active ingredient, Lidocaine. This Boxed Warning is included to inform users against its use for teething pain in infants due to the documented risk of serious adverse reactions.

How should Prolong be stored and disposed of?

All storage and disposal requirements for Prolong (Lidocaine Hydrochloride Aqueous Solution) are determined by official regulatory labeling to maintain product stability and safety.

Official Storage and Handling

Requirement Classification
Storage Temperature Store at Controlled Room Temperature (20 C to 25 C).
Freezing/Heat Protect from freezing and excessive heat.
Protection Keep in the original container, tightly closed, and away from light (for specific formulations).
Stability after Use Single-dose containers must be discarded immediately after initial use.

Disposal and Safety

Unused or expired Prolong must be disposed of in accordance with local regulations for pharmaceutical waste, as documented by national health authorities. The product should be stored out of sight and reach of children and pets to prevent accidental exposure.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.

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