Indol

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Indol

Treatment option: Pain, Chronic Pain

Medically reviewed

Marina Burgos

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 Indol

What is Indol?

Indol is a pharmaceutical formulation containing the active ingredient propranolol, which belongs to a class of medications known as beta-blockers. It is primarily used to manage various conditions related to the cardiovascular system and the autonomic nervous system by modulating the body's response to certain nerve impulses.

Therapeutic Mechanism

Propranolol works by blocking beta-adrenergic receptors in the body. By inhibiting these receptors, the medication reduces the physical effects of adrenaline and similar substances. This physiological action results in a decreased heart rate, reduced demand for oxygen by the heart muscle, and a lowering of blood pressure. It also helps in stabilizing heart rhythms and can reduce the physical symptoms associated with overactivity of the sympathetic nervous system.

Primary Clinical Uses

Indol is prescribed for several distinct medical purposes:

  • Cardiovascular Health: It is used to treat hypertension (high blood pressure), manage angina pectoris (chest pain), and control certain types of cardiac arrhythmias (irregular heartbeats).
  • Prevention of Migraines: It is frequently used as a preventive measure to reduce the frequency and severity of migraine headaches.
  • Management of Tremors: The medication is effective in treating essential tremor, a neurological condition that causes involuntary shaking.
  • Physical Symptoms of Anxiety: It can be used to manage the physical manifestations of situational anxiety, such as a rapid heartbeat or sweating, by limiting the body's "fight or flight" response.
  • Post-Myocardial Infarction: It is often utilized following a heart attack to improve long-term survival rates and reduce the risk of subsequent cardiac events.

Pharmacological Profile

As a non-selective beta-blocker, Indol acts on both beta-1 receptors (primarily located in the heart) and beta-2 receptors (located in the lungs and blood vessels). Because of its systemic reach, it is a versatile medication but requires careful clinical oversight to ensure it is appropriate for a patient's specific health profile, particularly for those with underlying respiratory conditions.

What side effects are possible with Indol?

Possible Side Effects and Safety Information for Indol

Regulatory agencies have issued warnings regarding the safety profile of Indol (based on documented indole-containing NSAID derivatives), particularly concerning risks to the cardiovascular and gastrointestinal systems.

Serious Adverse Reactions and Warnings

Serious risks documented in official labeling include:

System-Organ Class Serious Adverse Reactions (Documented Risk)
Cardiovascular System Increased risk of serious thrombotic events, including myocardial infarction (heart attack) and stroke, which can be fatal. This risk may increase with duration of use. The drug is contraindicated for the treatment of peri-operative pain in the setting of coronary artery bypass graft (CABG) surgery.
Gastrointestinal System Increased risk of serious adverse events, including bleeding, ulceration, and perforation of the stomach or intestines, which can be fatal. These events may occur without warning symptoms, and the risk is generally higher in older patients or those with a prior history of ulcer disease.
Other Major Risks Fetal Toxicity (avoidance is required from about 30 weeks gestation due to risks to the fetal heart and kidney function), Hepatotoxicity (liver damage), Renal Toxicity (kidney damage, including hyperkalemia), Hypertension (new onset or worsening of high blood pressure), and Anaphylactic/Allergic Reactions (including serious skin reactions like SJS/TEN and DRESS).

Common Adverse Reactions and Safety Considerations

The most commonly reported adverse reactions include headache, dizziness, dyspepsia (indigestion), and nausea.

Use is contraindicated in patients with a history of asthma, urticaria, or other allergic-type reactions after taking aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDs). Certain patient populations, such as the elderly, those with severe heart failure, or pre-existing renal impairment, require cautious use and close monitoring of vital signs and laboratory parameters (e.g., blood pressure, renal function, hematologic levels).

Overdose and Emergency Response

Overdose of Indol (Tramadol Hydrochloride) is officially documented to present with severe manifestations that require immediate emergency attention. The most critical documented sign is life-threatening respiratory depression, characterized by slow or shallow breathing, which can lead to fatal outcomes. Central Nervous System (CNS) effects are also prominent, ranging from profound sedation to stupor, coma, and a loss of consciousness. Other documented clinical signs include seizures or convulsions, severe hypotension, and cardiovascular events such as circulatory shock and cardiac arrest. Additionally, symptoms consistent with Serotonin Syndrome (e.g., agitation, fast heartbeat, or muscle spasms) may manifest in an overdose context.

Regulators mandate that immediate medical attention or contact with emergency services be sought for any suspected overdose, particularly if signs of severe breathing difficulty or unresponsiveness occur. The official antidote for opioid-induced respiratory depression is Naloxone. However, official labeling specifies that caution is required, as Naloxone administration carries a documented risk of increasing the likelihood of seizures in this setting. Supportive management includes measures such as re-establishing a patent airway and providing assisted ventilation. Furthermore, accidental ingestion of even one dose by children is noted as an extreme overdose risk.

Therapeutic Uses of Indol

What Indol Treats: Main Uses and Benefits

Indol is commonly used to manage symptoms related to physical discomfort that is moderate to moderately severe, relevant when supportive symptom management is appropriate. This medication is applied when short-term symptomatic assistance is needed to address discomfort that creates noticeable physiological strain.

Therapeutic Contexts

The therapeutic benefit is often sought across conditions presenting with acute episodes, such as symptoms related to physical discomfort following surgical procedures or significant trauma, and in long-term conditions characterized by periods of heightened symptoms like osteoarthritis and rheumatoid arthritis. The medicine is relevant in contexts marked by increased discomfort and can be used in palliative settings for conditions such as cancer pain.

Quick Fact: Relief for Moderate Pain Indol is considered relevant when symptoms related to physical discomfort interfere with daily functioning and additional symptomatic support is needed.

Patient Benefit Summary

Applied in clinical settings that involve acute or unstable symptom patterns, Indol helps address symptom clusters that may become intense or disruptive, supporting general well-being during symptomatic phases. It assists with managing these symptoms to contribute to improved day-to-day comfort.

Regulatory References

  1. NIH MedlinePlus overview

Eligibility and Restrictions for Use

This section summarizes the official criteria defining which populations are eligible or restricted from using Indol (Indomethacin), based solely on regulatory labeling.

Contraindications and Absolute Restrictions

Criteria Status Populations
Allergy/Sensitivity Contraindicated Patients with known hypersensitivity to Indol or with a history of asthma, urticaria, or allergic reactions to aspirin or other NSAIDs.
Cardiovascular/GI Contraindicated Patients following coronary artery bypass graft (CABG) surgery; those with active gastrointestinal bleeding, perforation, or ulceration.
Pregnancy Contraindicated Pregnant women starting at 30 weeks gestation and later, due to the risk of premature closure of the fetal ductus arteriosus.

Use Limitations and Special Populations

Criteria Status Populations
Pediatrics Not Established Safety and efficacy are not established for most oral formulations in children younger than 14 years of age.
Geriatrics Use with Caution Older adults should use with greater care due to increased risk of serious adverse effects, including gastrointestinal and central nervous system effects.
Organ/Physiological Use with Caution Patients with severe heart failure, advanced renal disease, or significant hepatic impairment require careful monitoring or dosage adjustment; use may be avoided entirely.

What should I know about interactions with other medicines?

Indol Interactions with other medicines and products

The interaction profile of Indol (Tramadol Hydrochloride) is defined by its effects on central nervous system activity and its metabolism via specific liver enzymes. Co-administration with Monoamine Oxidase Inhibitors (MAOIs) is formally contraindicated and must be separated by a mandatory period of at least 14 days.


Pharmacodynamic Interactions

A clinically significant interaction occurs with other Central Nervous System (CNS) Depressants (including alcohol and other opioids), leading to an additive risk of profound sedation and respiratory depression. Co-administration with other Serotonergic Drugs (e.g., SSRIs, SNRIs) increases the documented risk of Serotonin Syndrome. Furthermore, combining Indol with medicinal products that lower the seizure threshold may result in an increased seizure risk. Indol also interacts with Coumarin Derivatives such as Warfarin, which has been associated with reports of an elevated International Normalized Ratio (INR) and bleeding events.


Pharmacokinetic Interactions

Indol’s metabolism involves the CYP2D6 and CYP3A4 liver enzymes. Co-administration with CYP2D6 inhibitors may increase the concentration of the parent drug while decreasing the active metabolite, M1. Conversely, CYP3A4 inducers, such as Carbamazepine, significantly reduce tramadol serum concentrations, resulting in a reduced analgesic effect. A specific caution exists for individuals identified as CYP2D6 Ultra-Rapid Metabolizers, who may face an increased risk of opioid toxicity and respiratory depression due to rapid conversion to the active metabolite.

Mechanism of Action

Indol: Mechanism of Action Overview

The mechanism of Indol centers on its role as a multi-target inhibitor, primarily affecting cellular growth and communication through a pharmacodynamic mechanism focused on specific intracellular pathways. It initiates its action by binding to and blocking the activity of key receptor tyrosine kinases (RTKs), such as VEGFR and PDGFR, at a molecular level.

This specific inhibition prevents the phosphorylation cascade necessary for downstream signal transduction. By modifying the activity of essential growth and survival pathways, including the PI3K/Akt/mTOR and NF-κB signaling cascades, the drug alters cell cycle progression. The intracellular consequence is the initiation of apoptosis (programmed cell death) and the modification of signaling critical for angiogenesis (new blood vessel formation). This mechanism results in a physiological state characterized by restricted cell development and reduced vascularity within affected tissues, modulating physiological activity at the cellular level.

Dosage and Administration Information

Official Administration Guidelines

Indol is a prescription non-steroidal anti-inflammatory drug (NSAID).


Administration Scope Details
Route of Administration Oral (Capsules) or Rectal (Suppositories)
Dosing Schedule Initial dose is typically 25 mg two or three times a day. The total daily dosage should generally not exceed 200 mg
Titration/Adjustment Dosage may be increased by 25 mg or 50 mg at weekly intervals until a satisfactory response is obtained.
Timing in Relation to Meals Must be taken with food, immediately after meals, or with an antacid to promote correct administration.
Special Procedural Conditions The required procedure is to use the lowest effective dosage for the shortest duration consistent with individual treatment goals.
Nighttime Dosing Up to 100 mg of the total daily dose may be administered at bedtime, either orally or as a suppository, for persistent night pain or morning stiffness.
Age-Group Rules The lowest effective dosage for the shortest duration is specifically emphasized for elderly patients, who are noted to be at greater risk for serious gastrointestinal events.

Resulting Procedural Structure

The official instructions mandate that therapy begins with a low, divided dose to be taken with food, establishing the fundamental administration method. The regimen allows for controlled dose escalation in fixed increments (25 mg or 50 mg) at mandated weekly intervals if needed, but defines a maximum total daily limit. This structure ensures that drug use is initiated at a minimal level and progresses methodically only as required, while incorporating specific timing rules for administration to manage persistent nighttime symptoms and ensure patient compliance with administration conditions.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Indol

Evidence for use in Chronic Non-Cancer Pain

Research concerning conditions characterized by chronic symptom patterns, such as osteoarthritis and certain types of chronic low back pain, is primarily based on short-term Randomized Controlled Trials (RCTs). These studies were used in research exploring how symptoms change over time and outcomes related to physical discomfort. Researchers examined adult populations, monitoring changes in patient-reported outcomes describing perceived discomfort and daily functioning or activity level.

Studies reported patterns in measured pain scores over the observation period when compared against placebo or active comparators. Systematic reviews summarizing pooled data from these trials often reported that the measured change in pain scores was modest. Studies frequently reported high rates of participant withdrawal, which limits the data available to characterize persistent outcomes.

Evidence for use in Acute and Palliative Pain Settings

Research has explored the use of Indol in contexts involving acute symptom patterns, such as those following surgical procedures, using short-course RCTs. Findings described that the use of Indol was associated with measured differences in pain scores during the immediate post-procedure phase.

Research also examined Indol in the context of palliative care, in studies evaluating chronic discomfort in patients with conditions like cancer. Studies explored the use of Indol alongside or versus certain other weak opioid agents commonly used in established palliative protocols. The evidence derived from acute settings is primarily based on trials assessing short-term or episodic symptom patterns, often covering only a few days of observation.

Research Gaps and Special Populations

There is limited information for long-term outcomes. Most follow-up durations were limited, providing data primarily for group-level observations without characterizing long-term outcomes. Extended-duration data are limited; consequently, evidence on outcomes related to systemic or functional imbalance over prolonged periods, and on long-term outcomes, remains scarce.

Research has also explored Indol's use in distinct populations, most notably children and adolescents, although this evidence is primarily related to metabolism and safety monitoring rather than efficacy trials. Studies reported that the metabolism of Indol may vary widely among pediatric patients, which correlates with substantial regulatory restrictions on its use. The high drop-out rates in trials reflect the limitations regarding the generalized patterns observed in the studies.

Key Studies & References

  1. Assessment of the clinical benefits and risks of tramadol in patients with chronic non-cancer pain: a systematic review and meta-analysis

Frequently Asked Questions (FAQ)

Common questions about Indol (FAQ)

Q: Is Indol considered an over-the-counter medicine or is it prescription-only?

Regulatory documents classify this medication as a prescription-only drug. This classification is due to its known toxicity and potential for serious harmful effects, requiring the supervision of a licensed practitioner.

Q: Does Indol affect a person’s ability to drive or operate machinery?

Official documents contain advice to avoid driving or operating hazardous machinery. This instruction is due to the associated risk of drowsiness and dizziness, and should be followed until the medication's effects are known.

Q: How long does it typically take for Indol to start working after the first use?

According to clinical data, the immediate-release formulation of this drug typically begins to provide pain relief within about one hour after administration.

Q: What is the difference between Indol and similar medicines used to treat the same condition?

Official information indicates that the drug's mechanism is multimodal. It acts by weakly binding to mu-opioid receptors while also blocking the reuptake of two chemical messengers, serotonin and norepinephrine. This dual action is the key feature that distinguishes it from medicines that rely solely on the opioid pathway for pain management.

Q: Can Indol be taken by people with a history of heart problems?

The official label reports a risk of severe hypotension, which means low blood pressure. Official guidance indicates that the drug is advised against in patients experiencing circulatory shock. It is important to review a full cardiac history with a medical professional.

Q: Is Indol safe to use during pregnancy or while breastfeeding?

Regulatory documents state that prolonged use during pregnancy can lead to Neonatal Opioid Withdrawal Syndrome (NOWS) in the newborn. Use during lactation is generally advised against in official guidance because of the potential for serious adverse reactions in the infant.

Q: What are the most common signs of an allergic reaction to Indol?

Anaphylaxis and serious hypersensitivity reactions can occur with this medication. Signs documented that require immediate medical review include rash, hives, or swelling of the face, lips, tongue, or throat.

Q: Are there any foods or beverages that are officially advised to be avoided while using Indol?

Official regulatory documents contain strong advice against the concurrent use of the medication with alcohol. This is due to the potential for severe side effects, including profound sedation, respiratory depression, coma, and death.

Q: What conditions relating to the liver or kidneys would prevent someone from using Indol?

The drug is primarily processed by the liver and eliminated by the kidneys. Therefore, caution is advised for patients with hepatic (liver) or renal (kidney) impairment, and dose adjustments may be required, as the drug’s elimination depends on these organs.

Q: Is Indol considered a habit-forming or addictive substance?

Yes, regulatory documents classify this medication as a Schedule IV controlled substance. This classification is based on the acknowledged risks of addiction, abuse, and misuse, which are serious concerns and may lead to overdose.

Q: What kind of monitoring or lab tests might be mentioned in official documents for Indol use?

Official information recommends close patient monitoring, particularly during the start of therapy and after any dosage adjustment. Monitoring focuses on signs of respiratory depression (shallow breathing) and excessive sedation, especially in older or debilitated patients.

Q: What is the active ingredient in Indol and are there any inactive ingredients that cause concern?

The active ingredient is Tramadol Hydrochloride. Official product labeling lists all inactive ingredients, which may contain components that could be relevant to patients with known allergies or sensitivities.

Q: Is there a black box warning associated with Indol in the official prescribing information?

Yes, official prescribing information includes a Boxed Warning, which is the strongest type of warning required by regulators. This warning addresses critical risks such as addiction, life-threatening respiratory depression, and neonatal opioid withdrawal syndrome.

Q: What is the official recommendation if someone misses a scheduled administration of Indol?

Official information suggests skipping the missed dose and returning to the regular schedule. Regulatory guidance advises against taking a double dose to make up for the missed one.

Q: What is the purpose of the initial patient counseling described for Indol?

Patient counseling is required to ensure understanding of the medication’s significant risks. This includes the risks of addiction and misuse, as well as instructions on safe storage and disposal.

Q: Does Indol cure the underlying condition or only manage the symptoms?

The official indications state that the drug is for the management of pain. This means its primary function is to relieve or control symptoms rather than to cure the underlying condition causing the discomfort.

Q: What happens in the body when Indol stops working or is discontinued?

Rapid discontinuation is advised against in official guidance, as it can result in serious withdrawal symptoms. Official guidelines state that the dosage should be reduced gradually before the medication is stopped completely.

Q: Do studies examine the impact of Indol on mood or anxiety levels?

Official information notes that common side effects can include changes in mood and nervousness. This indicates that the drug may have an impact on a patient's emotional state.

Q: Is it acceptable to crush or split the Indol tablet, based on product information?

Product information contains instructions to swallow the tablet whole. Specifically, extended-release formulations must not be cut, crushed, chewed, or dissolved, as this can lead to the rapid release of a potentially harmful dose.

Q: How long does Indol remain in a person's system after the last dose?

Clinical pharmacology data indicates that the average elimination half-life for the parent drug is around 6.3 hours. Most of the drug is eliminated from the body within about two days, which is typically four to five half-lives.

Q: Does Indol require a gradual dose reduction (tapering) when stopping?

Yes, official regulatory documents state that the dosage must be gradually reduced (tapered) before complete discontinuation. This measure is necessary to minimize the risk of experiencing opioid withdrawal symptoms.

Q: Can patients with pre-existing mental health conditions use Indol?

Official documents advise caution when using the drug in patients taking tranquilizers or antidepressants. Furthermore, official guidance states that use is not recommended for patients who are suicidal or addiction-prone.

Q: What is the risk of overdose associated with Indol, as described in regulatory documents?

The risk of overdose is serious and is highlighted in regulatory warnings. The documented signs of overdose include fatal respiratory depression, seizures, extreme drowsiness, and coma.

How should Indol be stored and disposed of?

How to Store and Dispose of Indol? (Tramadol Hydrochloride)

Indol, which contains Tramadol Hydrochloride, must be stored and disposed of according to official regulatory requirements to maintain its stability and ensure compliance with controlled substance regulations.

Storage and Handling

Requirement Condition
Temperature Store at controlled room temperature, 20 C to 25 C.
Protection Keep in the original, tightly closed container and protect from moisture and excessive heat.
Freezing Do not freeze liquid formulations (e.g., oral solution/syrup).
Child Safety Keep medicine out of the sight and reach of children.

Disposal

Dispose of unused or expired product following federal and local regulations for controlled substances. It is recommended to use official drug take-back programs; generally, the medication should not be flushed down the toilet.

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

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