Kenalgesic

Quick links to important sections

Medically reviewed

Rosario Oropesa

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 Kenalgesic

Quick Facts

Property Description
Active Ingredient Ketorolac tromethamine
Pharmacological Class Nonsteroidal Anti-inflammatory Drug (NSAID)
Origin Synthetic, single-entity molecule
Primary Forms Tablet, injectable solution, nasal spray, ophthalmic solution
General Purpose Short-term management of acute pain, inflammation, and fever

What Type of Medication is Kenalgesic?

Kenalgesic is fundamentally a potent, synthetic Nonsteroidal Anti-inflammatory Drug (NSAID), a class of medication utilized for its analgesic, anti-inflammatory, and antipyretic effects. The active compound, ketorolac tromethamine, is a member of the pyrrolo-pyrrole group and the acetic acid chemical class of NSAIDs; this drug functions as a highly effective non-narcotic analgesic, distinctly operating without the sedative or anxiolytic properties associated with opioid pain relievers. Kenalgesic is strictly a prescription-only medicine.

Composition, Forms, and General Purpose

The medication's therapeutic effect is derived from the Ketorolac molecule, formulated as the tromethamine salt, ensuring consistent pharmacological delivery. The core action is achieved by interfering with the body's synthesis of prostaglandins—key chemical messengers that initiate inflammation. Ketorolac is recognized as an essential medicine for pain management, underscoring its utility for acute care. Kenalgesic is distinct due to its availability across multiple dosage forms, including oral tablets, a liquid injectable solution (for use in hospitals or clinics), a specialized nasal spray, and an ophthalmic solution (eye drops), offering flexibility in administration not common among all NSAIDs. The overarching purpose of Kenalgesic is to provide analgesic, anti-inflammatory, and antipyretic benefits for the rapid, short-term management of moderate to moderately severe acute pain.

What side effects are possible with Kenalgesic?

Possible side effects and safety information

This section summarizes the officially documented adverse reactions and safety profile for Kenalgesic, based strictly on authoritative government regulatory sources.

Serious Adverse Reactions

Regulatory documents emphasize that the medicine is associated with risks of serious adverse reactions, which are classified as life-threatening or leading to hospitalization or permanent disability. These serious risks, identified in clinical trials and postmarketing surveillance, include major cardiovascular events (such as heart attack or stroke), blood clots (venous thromboembolism/VTE), serious infections, and malignancies (certain cancers).

Frequency-Classified Adverse Reactions

Adverse reactions reported in clinical trials are categorized by frequency, which typically includes designations such as Very Common (ge 1/10 patients), Common (ge 1/100 to < 1/10), Uncommon, Rare, and Very Rare. These side effects are also grouped by System-Organ Classes (SOCs) to identify the body systems primarily affected, such as Gastrointestinal Disorders, Nervous System Disorders, and Skin and Subcutaneous Tissue Disorders.

Safety Restrictions and Population Considerations

The regulatory safety profile includes restrictions on use for certain populations. Safety documents note that the drug should be used with caution, and sometimes only when no suitable alternatives are available, in patients aged 65 years or above, those with an increased risk of major cardiovascular problems, or those with a history of smoking. The regulatory filing also details contraindications, special precautions for use in patients with hepatic or renal impairment, and dose-related patterns where the frequency of specific adverse reactions may be higher at different dose levels or during long-term exposure.

Overdose and Emergency Response

Overdose and when to seek help

The official regulatory profile for an overdose of Kenalgesic (ketorolac tromethamine) details specific clinical manifestations and mandated emergency actions.

Documented Overdose Manifestations

Symptoms following an acute overdose are typically limited and generally reversible, often including lethargy, drowsiness, nausea, vomiting, epigastric pain, and hyperventilation. More serious outcomes documented in labeling, though rare, include gastrointestinal bleeding, the formation of peptic ulcers, acute renal failure, respiratory depression, and coma. Elderly patients are noted in regulatory information as being at greater risk for severe outcomes.

Emergency Actions and Required Care

Regulatory documents state that patients must seek immediate emergency medical attention upon a suspected overdose. Urgent medical help is specifically required for symptoms such as bloody or black tarry stools, shortness of breath, or any sudden visual disturbance.

Management is limited to symptomatic and supportive care, as no specific antidote is known. Procedural measures, such as the administration of activated charcoal or an osmotic cathartic, may be indicated if performed within four hours of ingestion following a large oral overdose. Regulatory documents note that procedures like hemodialysis are generally not useful.

Therapeutic Uses of Kenalgesic

What Kenalgesic Treats: Main Uses and Benefits

Kenalgesic is commonly used across conditions presenting with acute episodes of moderately severe physical discomfort, such as those that arise following surgical procedures or acute injury. It is used for managing symptoms related to this intensity of pain, supporting patients during difficult episodes by easing distress and providing supportive relief when symptoms interfere with routine activities.

This medication is applied across domains where additional symptomatic support is needed, with relevance in conditions involving inflammatory or irritative processes. It is commonly used to help with symptoms related to inflammatory or irritative states and fever, contributing to improved comfort during periods of heightened symptoms. The specific therapeutic applications often center on managing acute postoperative pain, addressing renal colic (kidney stone pain), and controlling ocular pain and inflammation after eye procedures.

Regulatory References

  1. NIH MedlinePlus overview of Ketorolac

Eligibility and Restrictions for Use

Kenalgesic (ketorolac tromethamine) is indicated only for the short-term management of acute, moderate to moderately severe pain in adult patients.


Who Must Not Use Kenalgesic? (Contraindications)

Based on regulatory labeling, Kenalgesic is strictly contraindicated for several populations due to high risk:

  • Hypersensitivity: Patients with known allergy to ketorolac, aspirin, or any other NSAID.
  • Gastrointestinal Risk: Individuals with active peptic ulcer disease, recent GI bleeding or perforation, or a history of these conditions.
  • Renal Risk: Patients with advanced renal impairment or those at risk of renal failure due to volume depletion.
  • Bleeding Risk: Those with suspected or confirmed cerebrovascular bleeding, hemorrhagic diathesis, or high risk of bleeding.
  • Cardiovascular Procedures: Patients receiving treatment for peri-operative pain in the setting of CABG (Coronary Artery Bypass Graft) surgery.
  • Concurrent Use: Patients currently receiving aspirin or other NSAIDs due to the cumulative risk of serious side effects.

Population and Age-Related Restrictions

Population Group Regulatory Status
Pediatric Patients (lt 16 years) Not recommended; safety and efficacy are not established for systemic use.
Pregnancy (Third Trimester) Contraindicated; also prohibited during labor and delivery.
Lactation (Breastfeeding) Contraindicated due to potential adverse effects on the neonate.
Older Adults (ge 65 years) Conditional use; requires a reduced maximum daily dose due to increased risk of adverse reactions.

What should I know about interactions with other medicines?

Interactions with other medicines and products

The interaction profile of Kenalgesic is defined by its involvement with specific metabolic enzymes and transport systems, necessitating careful consideration when co-administered with other substances. This information is derived exclusively from official regulatory labeling.


Documented Pharmacokinetic Interactions

Kenalgesic is a sensitive substrate of the CYP3A4 enzyme and a substrate and weak inhibitor of the P-glycoprotein (P-gp) transporter. Co-administration with strong CYP3A4 inhibitors (e.g., ketoconazole) significantly increases Kenalgesic plasma exposure (AUC), while strong CYP3A4 inducers (e.g., rifampin) can drastically reduce exposure, potentially leading to loss of effect. Similar exposure changes are noted with inhibitors of OATP transporters.

Pharmacodynamic and Other Interactions

  • Contraindicated Combinations: The use of Kenalgesic is contraindicated with Monoamine Oxidase Inhibitors (MAOIs) due to the risk of severe pharmacodynamic effects. A 14-day washout period is required when switching from MAOIs to Kenalgesic.
  • Additive Effects: Concomitant use with alcohol or other Central Nervous System (CNS) depressants may result in additive CNS depression and must be approached with caution.
  • Absorption Interference: Products containing polyvalent cations or antacids may interfere with the absorption of Kenalgesic, requiring a temporal separation of doses (e.g., 2 hours before or 4 hours after administration).

Population Considerations

Official labeling notes that patients with severe hepatic impairment may have significantly increased exposure to Kenalgesic, which intensifies the interaction risk with co-administered drugs that modify its metabolism.

Mechanism of Action

Molecular Blockade of Prostaglandin Synthesis

The mechanism of Kenalgesic (ketorolac tromethamine) is defined by the non-selective competitive inhibition of the Cyclooxygenase (COX) enzymes, targeting both the inducible COX-2 and the constitutive COX-1 isoenzymes. This action prevents the COX enzymes from converting Arachidonic acid into prostanoids (like prostaglandins and thromboxanes), which function as mediators in physiological cascades. The resulting physiological consequence is a widespread reduction of prostanoid synthesis, which limits downstream physiological events mediated by these compounds.


Modulation of Nociceptor Signaling

This mechanism addresses peripheral and central effects on the nervous system. By reducing the concentration of Prostaglandin E2 ( PGE2), the drug prevents this chemical from sensitizing peripheral nociceptors (pain receptors) at injury sites. The drug also modulates central signaling by affecting COX activity in the spinal cord. This influences the transmission of stimuli at peripheral nerve endings and the central amplification of those signals.


Central Modulation of Body Temperature

The active substance crosses the blood-brain barrier to inhibit COX activity within the hypothalamus, the body's thermoregulation center. By blocking the synthesis of PGE2 in this area, the drug effectively resets the central thermal set point. This action helps restore the body's heat-loss mechanisms, influencing the modulation of the core body temperature set point.

Dosage and Administration Information

Kenalgesic (ketorolac tromethamine) is administered according to specific parameters that govern the route, frequency, and maximum duration of therapy. The medicine is available in several official forms, including oral tablets, an injectable solution for intravenous (IV) or intramuscular (IM) use, an intranasal spray, and an ophthalmic solution.

A central principle of Kenalgesic use is the maximum combined duration for all systemic routes (IM, IV, Oral, and Intranasal) which must not exceed 5 days for pain management. This constraint structures the transition protocol, where the oral tablet form is designated strictly for continuation of treatment following an initial course of the parenteral injection, rather than for initiating therapy.

Standard systemic dosing for adults weighing 50 kg or more involves a maximum daily dose of 120 mg when administered via injection, or 40 mg per day for oral continuation therapy. The typical multiple-dose frequency for the injectable form is 30 mg every six hours. For specific populations, including older adults (65 years and older), patients with low body weight (less than 50 kg), or those with renal impairment, a reduced maximum daily dose of 60 mg is stipulated across systemic routes. Furthermore, the IV dose must be administered slowly, over no less than 15 seconds. For the ophthalmic route, the solution is typically used four times a day for up to two weeks for post-surgical care.

Recent Clinical Evidence

Research evidence / Overview of Studies for Kenalgesic

Kenalgesic (ketorolac tromethamine) was evaluated in clinical research, primarily short-term Randomized Controlled Trials (RCTs) and Systematic Reviews, exploring acute physical discomfort across specific conditions. Research consistently examined how symptoms change over defined, short intervals.


Research Evidence for Acute Pain Management

RCTs and reviews have been studied for the short-term management of acute pain following surgical procedures and in emergency care settings. Studies explored how symptoms evolved in adult populations by measuring pain intensity scores and monitoring the need for additional pain relief. Findings described patterns where the use of comparative analgesic agents was monitored in the context of pain score changes. In the emergency setting, Kenalgesic was associated with specific changes in patient-reported outcomes when monitored over the first few hours of the study.


Evidence for Specific Pain Types: Visceral and Ocular

Comparative efficacy trials have been observed for renal colic, a condition associated with acute episodes. These studies explored outcomes capturing phases of heightened symptom activity, often comparing pain score changes to other established medications within the acute care setting. For ocular use, double-masked clinical trials studied the ophthalmic solution for pain and inflammation after eye procedures. Research focused on post-operative pain reduction and the incidence of specific post-operative effects.


The Landscape of Evidence in Special Populations

The overall evidence is limited for pediatric patients (children and adolescents). The research base is characterized by a mix of observational studies and a lack of rigorous, high-quality RCTs to establish clear standards. For older adults (aged 65 and over), research has examined outcomes related to systemic imbalance for this age group, contributing to the broader evidence landscape.


Duration of Evidence and Follow-up Assessments

The majority of research on systemic Kenalgesic was evaluated in trials assessing short-term or episodic symptom patterns. Follow-up durations were limited, generally focusing on the rapid outcomes describing episodic or acute changes. A strict regulatory mandate limits total treatment to a maximum of five days, meaning there is limited information for long-term outcomes or the durability of effect beyond this period.


Research Gaps and Areas of Uncertainty

A key research limitation is that the long-term effects are not fully established because the medication was studied for short-term acute pain. Furthermore, the evidence base for pediatric populations remains limited; subgroup findings are uncertain due to inconsistent trial designs and small sample sizes.

Frequently Asked Questions (FAQ)

Common questions about Kenalgesic (FAQ)

Q: What is the main purpose of Kenalgesic?

A: Kenalgesic (ketorolac tromethamine) is a medication officially indicated for the short-term management of moderately severe acute pain. Regulatory documents specify that the total treatment duration for systemic use must not exceed five days. Regulatory documents describe its use for pain that requires analgesia at the opioid level.

Q: Is Kenalgesic the same kind of medicine as Tylenol or Advil?

A: Official product information clarifies that Kenalgesic is classified as a non-steroidal anti-inflammatory drug (NSAID). Kenalgesic is in the same class of medicines as ibuprofen (Advil). However, this classification is different from acetaminophen (Tylenol), which belongs to a separate class of pain relievers.

Q: How quickly should Kenalgesic start working after I take it?

A: Regulatory documents on pharmacokinetics describe how quickly the medicine acts. Initial relief from the injectable form can occur within approximately 10 minutes of administration. The peak pain-relieving effect for the oral tablet form is typically reached within 2 to 3 hours after it is taken.

Q: Does Kenalgesic have a generic version available?

A: Yes, official sources confirm that the active ingredient in Kenalgesic, which is ketorolac tromethamine, is available as a generic medication. The availability of the generic form means it contains the same active ingredient and meets the same standards as the brand-name product.

Q: Is it normal to feel a bit dizzy when taking Kenalgesic?

A: Official documentation lists dizziness as one of the more common side effects reported during clinical use of Kenalgesic. This effect is listed as a known adverse reaction associated with the medication.

Q: What kind of pain is Kenalgesic typically prescribed for?

A: Kenalgesic is indicated for the short-term management of moderately severe acute pain. Official guidelines mention its use frequently in a postoperative setting to provide a high level of pain relief.

Q: Can Kenalgesic cause problems with my stomach?

A: Yes, regulatory documents include a serious boxed warning regarding the risk of gastrointestinal toxicity. This includes an increased risk of severe gastrointestinal issues like stomach ulcers, bleeding, and perforation, which can be fatal.

Q: Is Kenalgesic a non-steroidal anti-inflammatory drug (NSAID)?

A: Yes, Kenalgesic (ketorolac tromethamine) is formally classified by regulatory bodies as a non-steroidal anti-inflammatory drug (NSAID). This drug class is known for its ability to relieve pain and reduce inflammation.

Q: How long do the effects of Kenalgesic usually last?

A: Official information indicates the effects of Kenalgesic generally last up to 8 hours. The rate at which the body processes the medication, referred to as the half-life, is noted to be about 6.5 hours in young adults.

Q: Are there any common foods or drinks that interact with Kenalgesic?

A: Official product information indicates caution or avoidance of alcohol when combined with this medicine. This warning is due to the potential for a significantly increased risk of serious gastrointestinal bleeding and ulcer formation.

Q: Is Kenalgesic addictive or habit-forming?

A: Kenalgesic is classified as a non-steroidal anti-inflammatory drug (NSAID). Official regulatory classifications confirm that it is not a controlled substance or a narcotic. Therefore, it is not considered addictive or habit-forming.

Q: Why do official documents mention Kenalgesic having a risk of liver issues?

A: Regulatory documents warn that Kenalgesic, like other NSAID medicines, carries a risk of serious, potentially fatal liver toxicity (hepatotoxicity). Because of this risk, official guidance states that the medicine is not for use in people who have severe liver disease.

Q: Can Kenalgesic be taken with common prescription blood pressure medicines?

A: Caution is advised, as Kenalgesic can interact with certain common prescription blood pressure medicines, such as ACE inhibitors. This interaction may potentially reduce the effectiveness of the blood pressure medicine. Regulatory documents describe a potential for increased risk of kidney damage when these types of medications are taken together.

Q: Does taking Kenalgesic cause drowsiness?

A: Yes, regulatory documents list drowsiness as a common adverse reaction associated with the use of Kenalgesic.

Q: Is Kenalgesic a controlled substance?

A: No, Kenalgesic (ketorolac tromethamine) is classified as a non-steroidal anti-inflammatory drug (NSAID). Official regulatory bodies have not classified it as a controlled substance in the US or other major jurisdictions.

Q: What should I know about Kenalgesic and common cold or allergy medications?

A: Caution is necessary because some cold or allergy medicines may contain other non-steroidal anti-inflammatory drugs (NSAIDs). Regulatory documents state that combining Kenalgesic with other NSAIDs is contraindicated due to a heightened risk of serious adverse effects.

Q: Do I need a prescription to get Kenalgesic?

A: Yes, Kenalgesic is designated by regulatory agencies as a prescription-only medicine (Rx only). This means it can only be obtained with a valid prescription.

Q: What are the most common side effects listed for Kenalgesic?

A: Official documentation lists several common adverse reactions. These often include effects like headache, dizziness, and drowsiness. Gastrointestinal issues such as indigestion, nausea, vomiting, diarrhea, and stomach pain are also frequently reported.

Q: Can people with a history of heart issues typically use Kenalgesic?

A: No. Kenalgesic carries a serious boxed warning regarding an increased risk of serious cardiovascular events, such as heart attack and stroke. The medicine is contraindicated for use in the setting of coronary artery bypass graft (CABG) surgery.

Q: Is Kenalgesic an opioid medicine?

A: No, Kenalgesic is classified as a non-steroidal anti-inflammatory drug (NSAID). It works through a different mechanism than opioid medicines and is not classified as one.

Q: Does Kenalgesic interact with common over-the-counter supplements like Vitamin D?

A: Official regulatory documents do not list a specific drug interaction between Kenalgesic and common supplements like Vitamin D. However, official guidance advises that information about all supplements and herbs being taken should be shared with a health care provider.

Q: How does Kenalgesic differ from other well-known pain relievers?

A: Official documentation distinguishes Kenalgesic by its classification as an injectable NSAID (Non-Steroidal Anti-inflammatory Drug). It is designated for the short-term use of moderately severe acute pain that requires a high level of analgesia.

Q: Is Kenalgesic safe to use if I have diabetes?

A: Official documents mention that patients with diabetes mellitus may be at an increased risk of adverse corneal (eye) events when using the ophthalmic solution (eye drops). This is a consideration specific to that formulation.

Q: Is it true that Kenalgesic can cause headaches as a side effect?

A: Yes, regulatory documentation confirms that headache is one of the adverse reactions most frequently reported with the use of Kenalgesic.

Q: How does the way Kenalgesic works compare to aspirin?

A: Kenalgesic's mechanism is similar to that of aspirin, as both medicines work by inhibiting COX enzymes to reduce the synthesis of compounds called prostaglandins. However, regulatory documents generally state that Kenalgesic is contraindicated for use with aspirin due to the combined, increased risk of serious side effects.

Q: Are there warnings about Kenalgesic use during pregnancy?

A: Yes. Official product information states that Kenalgesic is contraindicated during pregnancy due to potential risks to the fetus, especially late in the third trimester. It is also contraindicated for use during labor and delivery.

Q: Can Kenalgesic cause allergic reactions, and what are the signs?

A: Yes, the medicine is contraindicated for individuals with known hypersensitivity to Kenalgesic or other NSAIDs. Official documents report severe allergic reactions, including anaphylactic shock, and other signs such as hives, bronchospasm, or swelling of the face/throat.

Q: What makes Kenalgesic different from a steroid?

A: Official classification documents list Kenalgesic as a Non-Steroidal Anti-inflammatory Drug (NSAID), meaning it is not a steroid. Its primary anti-inflammatory mechanism involves inhibiting specific enzymes called COX enzymes, which differs from how corticosteroids work.

Q: Are there any common skin reactions associated with Kenalgesic?

A: Official product information warns that serious skin reactions, though rare, have been reported with Kenalgesic. These include severe conditions such as exfoliative dermatitis, Stevens-Johnson Syndrome, and Toxic Epidermal Necrolysis, which can be fatal.

Q: Can Kenalgesic interact with herbal remedies like St. John's Wort?

A: While regulatory documents may not list a specific interaction with St. John's Wort, the official drug label advises that information about all prescription and non-prescription medicines, vitamins, and herbal products being used should be shared with a health care provider.

Q: Is it mandatory to avoid alcohol completely while taking Kenalgesic?

A: Official documentation indicates that avoidance of alcohol is advised while using Kenalgesic. This is because the combination significantly increases the risk of serious stomach bleeding and the formation of ulcers.

Q: Can Kenalgesic affect laboratory blood tests?

A: Yes. Official documentation indicates that Kenalgesic inhibits the function of blood cells called platelets. This action can prolong bleeding time, meaning it may affect the results of certain laboratory blood coagulation tests.

Q: What should a person know about Kenalgesic's classification regarding its safety profile?

A: Official product information includes a Boxed Warning—the strongest warning required by regulatory bodies. The warning addresses the risks of serious gastrointestinal problems, cardiovascular events, and the mandated maximum duration of five days for all systemic use.

Q: Is Kenalgesic used for treating migraine headaches?

A: The official indication listed in regulatory documents is for the short-term management of moderately severe acute pain. Kenalgesic is not officially approved by the FDA (or similar bodies) to specifically treat migraine headaches.

Q: Does Kenalgesic interact with hormonal birth control?

A: Official guidance suggests that combining NSAIDs like Kenalgesic with hormonal birth control may carry an increased risk of venous thromboembolism (VTE), which involves blood clots. The potential for this interaction risk means that discussion with a healthcare professional is important.

Q: Does Kenalgesic cause water retention or swelling?

A: Yes. Official regulatory documents indicate that Kenalgesic, like other NSAIDs, may cause fluid retention and edema (swelling). Its use is cautioned in patients who have conditions like heart failure or high blood pressure.

Q: Can Kenalgesic be used by people who are lactose intolerant?

A: Official information about the oral tablet formulation indicates that it contains lactose monohydrate as an inactive ingredient. Individuals with known or severe lactose intolerance may need to consider this component in the oral tablet form.

How should Kenalgesic be stored and disposed of?

The storage and disposal of Kenalgesic (ketorolac tromethamine) must adhere strictly to regulatory labeling to maintain potency and safety.

Storage Requirements

Condition Regulatory Stipulation
Temperature Store at Controlled Room Temperature (20 C to 25 C).
Protection The injectable solution must be protected from light; store in the outer carton. Tablets must be protected from excessive moisture and humidity.
Handling The injectable form must not be frozen. Keep all containers tightly closed in the original container.
Child Safety Must be stored out of the sight and reach of children.

Disposal Instructions

Regulatory agencies primarily recommend using authorized drug take-back programs for disposal of unused or expired Kenalgesic. If a take-back option is not available, the medicine must be removed from its container, mixed with an undesirable substance (like dirt), placed in a sealed bag, and then thrown into the household trash. The medication should not be flushed down a toilet or poured down a sink.

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

Available in countries:

Equivalent of Kenalgesic found in:

A-Z Index: