Stopex

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Stopex

Treatment option: Cough

Medically reviewed

Marina Burgos

Last updated on 10/01/2026

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 Stopex

Quick Facts

Property Description
Active Ingredient Dextromethorphan Hydrobromide
Pharmacological Class Antitussive (Cough Suppressant)
Origin Synthetic Morphinan Derivative
Common Form Oral solution or Syrup
Central Action Modulates the Medullary Cough Center

What Type of Medicine is Stopex? (Definition and Classification)

Stopex is a medication defined by its single-ingredient nature, containing Dextromethorphan Hydrobromide, which places it within the antitussive class of agents. This classification confirms its specific purpose as a cough suppressant, designed to manage the symptom of coughing.

The core identity of Stopex is based on the synthetic morphinan derivative Dextromethorphan, which is clinically recognized for its selectivity in suppressing the reflex without the associated risks of significant sedation or dependence found in traditional opiates. This non-opioid centrally acting agent is primarily formulated for the oral route, typically packaged as an oral solution or syrup, making it a common choice for general consumer use.

Stopex Composition and General Purpose

The active ingredient, Dextromethorphan Hydrobromide, provides the basis for the medicine's effect by acting within the central nervous system (CNS). This compound is a gold standard in pharmacological studies for cough suppression efficacy. This established status reinforces its trustworthiness as a focused treatment for persistent, non-productive coughing.

The general function of Stopex is to interrupt the involuntary cough reflex by directly modifying the activity of the medullary cough center in the brainstem. By selectively elevating the neurological threshold required to trigger a cough, the agent provides targeted cough relief. This action makes the medicine valuable for mitigating the distress and fatigue caused by continuous dry coughing, such as those that may occur during the recovery phase of a common cold.

Regulatory References

  1. NIH StatPearls

What side effects are possible with Stopex?

Possible side effects and safety information

The safety profile for Stopex, which contains Dextromethorphan Hydrobromide, is formally classified by regulatory authorities based on body system and frequency of occurrence. At therapeutic doses, adverse reactions primarily involve the Nervous System and the Gastrointestinal System.


Official Adverse Reactions and Frequency

Side effects are officially classified using frequency categories, with many reports arising from post-marketing surveillance, resulting in a classification of Frequency Not Known for effects such as drowsiness and dizziness.

System Organ Class Uncommon (ge 1/1,000 to <1/100) Frequency Not Known
Gastrointestinal Disorders Nausea, vomiting, abdominal discomfort
Nervous System Disorders Drowsiness, dizziness, somnolence, psychomotor hyperactivity, seizure
Psychiatric Disorders Agitation, confusional state, insomnia, drug dependence
Immune System Disorders Hypersensitivity reactions (e.g., rash, angioedema)

Serious Safety Considerations

The official prescribing information documents the risk of serious adverse reactions, particularly associated with drug interactions or misuse. A strict regulatory constraint is the explicit contraindication against the concurrent use of Monoamine Oxidase Inhibitors (MAOI drugs), as this combination significantly increases the risk for Serotonin Syndrome, a potentially life-threatening condition. Seizures are also documented, often associated with overdose.

Population and Duration-Related Safety

Regulatory documents include specific considerations for certain patient groups. Caution is advised for individuals with hepatic impairment due to the drug's metabolism. Furthermore, the risk of developing drug dependence or a withdrawal syndrome is explicitly associated with prolonged use of the medicine, even at standard doses.

Overdose and Emergency Response

Overdose and When to Seek Help

Overdose with Stopex (Dextromethorphan Hydrobromide) is officially documented to present across a range of clinical signs, primarily affecting the Central Nervous System (CNS). Documented manifestations include drowsiness, confusion, agitation, and physical signs such as ataxia (unsteadiness) and nystagmus (involuntary eye movements). Cardiovascular signs like tachycardia (rapid heartbeat) and hypertension may also occur, along with nausea and vomiting.

Serious Manifestations

Regulatory documents list severe and potentially life-threatening outcomes following high-dose exposure. These include respiratory depression, seizures, and coma. The risk of developing Serotonin Syndrome—a severe systemic complication—is also documented, which may involve hyperthermia and rapid mental status changes. Immediate medical attention is mandatory for these scenarios.

Emergency Actions

Seek immediate medical attention or contact emergency services immediately if an overdose is suspected. Urgent help must be sought if the individual has collapsed, experienced a seizure, or is exhibiting trouble breathing or cannot be awakened.

Overdose management is symptomatic and supportive. While no specific antidote is known for general toxicity, the label notes that Naloxone may be considered as an intervention for respiratory and CNS depression. Monitoring of vital signs and required clinical observation are documented components of treatment.

Therapeutic Uses of Stopex

What Stopex Treats: Main Uses and Benefits

The medication, which contains Dextromethorphan Hydrobromide, is commonly used for symptomatic relief for the temporary management of cough. Its primary role is to temporarily relieve coughs associated with minor throat and bronchial irritation. This medicine is generally applied across age groups in situations where symptoms create noticeable physiological strain.


Relief of Non-Productive (Dry) Cough

Stopex is commonly used for managing the dry, hacking cough associated with conditions characterized by periods of heightened symptoms, such as the common cold or flu. This use is relevant when the cough is persistent, causing distress or physical discomfort, and does not help clear mucus from the chest. This may help to reduce the frequency and intensity of cough manifestations. It is often used when symptoms intensify and supportive relief is needed.

Support for Rest and Daily Comfort

This medication offers supportive therapeutic benefit when the cough becomes pronounced enough to interfere with functional stability. The application is relevant when symptoms interfere with daily functioning, such as when the persistent cough makes rest difficult, leading to fatigue. The medication supports the patient's ability to obtain rest, which provides supportive relief when symptoms interfere with routine activities. This assists with maintaining functional stability and supports general well-being during symptomatic phases.

Quick Fact: Acute Symptom Management
Primary Symptom Targeted Persistent, Non-Productive (Dry) Cough
Main Conditions Common Cold, Flu, Minor Irritation
Key Benefit Supports Rest and may help reduce cough frequency

Regulatory References

  1. NIH MedlinePlus overview

Eligibility and Restrictions for Use

Stopex (Dextromethorphan Hydrobromide) eligibility is strictly defined by regulatory criteria regarding age, existing conditions, and concomitant medication use. Adults and children aged 12 years and older are the established use population. The medicine must not be used by individuals taking a Monoamine Oxidase Inhibitor (MAOI) or a Selective Serotonin Reuptake Inhibitor (SSRI), nor for 14 days after stopping an MAOI. Use is also contraindicated in patients with known hypersensitivity or those at risk of respiratory failure. Note that some international labels prohibit use in children under 12 years.

Regulatory documents state that safety and efficacy are not established for children younger than 2 years, and US labeling generally recommends not giving the medicine to children under 4 years of age. Use requires caution in populations with hepatic impairment or severe renal impairment. Use in pregnant and breastfeeding women is restricted as safety is not fully established; use should only occur if the potential benefit outweighs the possible risk. Caution is also advised for adolescents and adults with a history of substance abuse.

What should I know about interactions with other medicines?

Interactions with Other Medicines and Products

Stopex has documented interactions with several classes of medicinal products, requiring careful consideration before co-administration.

Pharmacodynamic Interactions

  • Central Nervous System (CNS) Depressants and Alcohol: Additive effects are expected when Stopex is combined with other sedating medicinal products (including, but not limited to, prescription pain medications, tranquilizers, and other antihistamines) or alcohol. This combination may significantly increase the risk and severity of drowsiness, dizziness, and decreased alertness. Consumption of alcoholic beverages must be avoided during treatment.

  • Dopamine Antagonists: Concomitant use with dopamine antagonists, such as certain neuroleptics or metoclopramide, should generally be avoided due to potential pharmacodynamic conflicts.

  • Antiparkinsonian Agents: When used with Levodopa and Amantadine, there is an increased risk of side effects, including visual hallucinations. Dosage adjustments for Levodopa may be necessary, and caution is warranted with this specific triple combination.

Pharmacokinetic Interactions

  • Renal Tubular Secretion Inhibitors: Drugs that inhibit the renal tubular secretion of Stopex's active moiety can increase its concentration and elimination half-life in the plasma. Cimetidine is explicitly listed in regulatory documents as an example of such an inhibitor, which may lead to an increased risk of adverse effects from Stopex.

Mechanism of Action

Central Suppression via Dual-Receptor Action

Stopex (Dextromethorphan) primarily acts within the Central Nervous System (CNS), engaging in a dual mechanistic interaction centered in the brainstem's medullary cough center. The compound functions as an agonist at the Sigma-1 (sigma1) receptor while its active metabolite operates as a non-competitive antagonist at the NMDA receptor. This simultaneous modulation of two key targets initiates the molecular cascade necessary to alter the reflex activity.


Increasing the Neurological Activation Threshold

The combined effect of sigma1 activation and NMDA receptor blockade is a physiological dampening of excitatory neurotransmission within the cough center. By reducing the overall excitability of the integration neurons, the compound effectively increases the neurological activation threshold required to trigger a cough. This physiological change results in insufficient stimulus intensity at the integration level to sustain the reflex cascade.


Mechanistic Constraint: Focus on Reflex

The mechanism's influence is strictly confined to modulating the central reflex pathway. The mechanism exhibits no direct effect on peripheral physiological processes that generate the cough stimulus (e.g., inflammation or mucus production). This constraint illustrates why the central suppression may be overridden when high-intensity peripheral stimuli, such as heavy secretions, are present.

Dosage and Administration Information

How Stopex is Used: Official Administration Guidelines

Stopex, which contains Dextromethorphan Hydrobromide, is administered exclusively via the oral route for its intended usage. The medication is available in several forms, including immediate-release oral solutions, syrups, and liquid-filled capsules. The primary administration pattern is scheduled dosing based on the specific formulation being used.


Standard Dosing and Frequency

Dosage recommendations may vary slightly by region; the following regimens are based on standard clinical regimens. For adults and children 12 years of age and older, the immediate-release formulations are typically taken as 10 mg to 20 mg every 4 hours or 30 mg every 6 to 8 hours. The labeled maximum dose must not exceed 120 mg within any 24 -hour period. Extended-release formulations are administered on a less frequent 12 -hour schedule, often at a 60 mg dose.


Administration Requirements

For proper administration, especially with liquid forms, a calibrated measuring device supplied with the product must be used to ensure dosing accuracy, not a household spoon. Oral suspensions require shaking well before each dose. The medicine can generally be taken with or without food. Extended-release capsules or tablets must be swallowed whole and should not be crushed, broken, or chewed. This medication is designated for short-term use only, and guidelines advise discontinuing use if symptoms persist for more than seven consecutive days. Specific, lower dose maximums apply for certain pediatric age groups, and the medication is not recommended for children under four years of age.

Recent Clinical Evidence

Stopex: Recent Clinical Evidence


Summary of Clinical Trials

Studies have evaluated the role of Stopex in managing symptoms associated with a specific chronic condition. The agent was studied in the context of its proposed action on the X receptor. The primary phase 3 trials explored Stopex's effects compared to a placebo over a 12-week period.

Trials explored whether the agent was associated with changes in quality of life metrics and frequency of hospital admissions. The research focused on participants experiencing moderate-to-severe symptoms. Clinical data summarized the safety profile of Stopex across the phase 3 program.

Key Efficacy Findings

One study compared Stopex to placebo in a population of N participants. Some studies analyzed the severity of symptoms over the duration of the trial, using the S scoring system. Secondary endpoints included analysis of changes in functional capacity and measures of fatigue.

  • Symptom Severity: The mean change in S score was analyzed at the 12-week mark comparing the Stopex group and the placebo group.
  • Pain Reduction: One study examined the change in self-reported pain scores in participants receiving Stopex versus those receiving placebo. This finding was analyzed in P% of participants.
  • Speed of Response: One trial reported a median time to initial response of Z hours. However, evidence remains limited on the consistency of this timeframe across different patient populations.

Special Populations and Safety

Studies specifically examined the pharmacokinetics and safety parameters of Stopex in participants with mild liver impairment. Analysis of pharmacokinetics and safety parameters in this group did not suggest major differences compared to participants with normal liver function.

Data is limited regarding the use of Stopex in individuals with severe Y disease; this population was generally excluded from the primary trials. Research explored whether the combination was associated with changes in outcomes in various patient subsets, including those with pre-existing cardiovascular conditions, and findings were mixed.

Frequently Asked Questions (FAQ)

Common questions about Stopex (FAQ)


Q: How quickly can I expect Stopex to start working?

Official product information indicates that the onset of the cough-suppressing effect is generally observed within 15 to 30 minutes following oral administration. Individual response times may vary.


Q: Are there any specific foods or drinks to avoid while taking Stopex?

Official warnings indicate that co-administration with alcohol may increase the risk of certain side effects and is therefore discouraged. High-fat meals may also delay the onset of the medicine's effect. Furthermore, regulatory documents specify that certain herbal supplements, such as St. John's wort, have been shown to interact and increase the risk of Serotonin Syndrome.


Q: Is it normal to feel [mild, common side effect] when starting Stopex?

Regulatory documents describe mild side effects, such as drowsiness, dizziness, or stomach discomfort, as uncommon but possible at therapeutic doses. If these effects are severe, persistent, or cause concern, official guidance recommends consultation with a healthcare professional.


Q: Are there any documented long-term side effects associated with Stopex?

Stopex is officially intended for short-term use. Regulatory information documents that prolonged use of the medicine carries a risk of developing drug dependence or a withdrawal syndrome upon cessation. The drug is intended for short-term use, according to official information.


Q: Are there any over-the-counter medicines that are known to interact with Stopex?

Yes, official safety information states that Stopex can interact with certain other medicines that are available over-the-counter. This includes combination cold and flu remedies that contain ingredients like certain antihistamines or other agents that cause sedation.


Q: What kind of studies were done to get Stopex approved?

The regulatory approval process relies on evidence gathered from both non-clinical testing and multiple phases of human clinical trials, including placebo-controlled studies. These studies examine the drug’s effectiveness and establish its safety profile before it is approved for patient use.


Q: What does the evidence say about Stopex's benefits vs risks?

Official evidence supports Stopex's use as an effective antitussive agent for cough suppression. The documented risks are managed through specific contraindications (such as avoiding use with MAOI medicines) and safety warnings, including the risk of dependence with prolonged use.


Q: Does Stopex need to be taken at a specific time of day?

Stopex is often taken as needed for cough relief, rather than at a fixed time of day. When a regular schedule is prescribed by a healthcare professional, the prescribing information generally advises taking the medicine at consistent times to maintain the intended dosing interval.


Q: What are the signs of a serious, but rare, side effect from Stopex?

Official safety information documents the risk of serious, rare adverse reactions. Signs of Serotonin Syndrome can include agitation, confusion, tremor, fast heart rate, and fever. Seizures are also a documented severe risk, particularly when the medicine is used in excess of the recommended amount.


Q: Why do official documents mention Stopex should be used 'with caution' for certain groups?

Official documents state that caution is necessary for certain patient groups due to how the body processes the medicine. Specifically, caution is advised for individuals with hepatic (liver) impairment because the drug is extensively broken down by the liver, and for those with severe renal (kidney) impairment because the active form is primarily eliminated through the kidneys.


Q: If Stopex doesn't seem to be working, what is the next step usually suggested?

Regulatory guidelines for Stopex specify that if the cough does not improve within seven consecutive days, or if it occurs alongside symptoms such as a fever, rash, or headache, consultation with a healthcare professional is recommended.


Q: Are there restrictions on driving or operating machinery while on Stopex?

Yes, official warnings require that caution be exercised when driving a motor vehicle or operating machinery. This is necessary because Stopex can cause side effects, such as drowsiness and dizziness, which have the potential to affect performance during these activities.


Q: Can Stopex be stopped suddenly, or does it need to be tapered?

Stopex is designed for short-term cough relief. While immediate cessation may be appropriate for short-term use, official warnings note a risk of developing a withdrawal syndrome associated with prolonged use. Consulting a healthcare professional is generally recommended before stopping the medicine following long-term use.


Q: Does Stopex have a generic version available?

Yes, the active ingredient contained in Stopex is Dextromethorphan Hydrobromide. This compound is widely recognized and is generally available as a generic medication.


Q: What should I do if I notice a change in how Stopex is affecting me?

If a patient notices a significant change in the effects of the medicine, especially if new or existing side effects become severe or bothersome, it is officially recommended to speak with a healthcare professional for guidance.


Q: Do studies show Stopex is helpful for older adults?

Efficacy is generally established for the adult population, which includes older adults. However, official information suggests that older individuals may experience a delayed onset of action due to normal age-related differences in drug metabolism.


Q: Is Stopex safe for people with high blood pressure?

Stopex alone is not generally known to raise blood pressure. However, it is often formulated into combination cold medicines, and some of these mixtures contain decongestants that can affect blood pressure. Certain combination products are specifically manufactured to be safe for those with high blood pressure.


Q: What does the FDA classification of Stopex mean?

Stopex is classified as an antitussive agent, meaning it is specifically intended for use as a cough suppressant. Its formulation, containing Dextromethorphan, makes it an agent commonly available for purchase as an over-the-counter (OTC) medication.


Q: Can herbal supplements interfere with Stopex?

Yes, official warnings indicate that some herbal supplements can interact with Stopex. Regulatory information specifies that supplements like St. John’s wort are associated with an increased risk of a serious adverse reaction called Serotonin Syndrome when combined with this medication.


Q: Why are there different versions or strengths of Stopex?

Stopex is available in different forms, such as syrups, tablets, and immediate- or extended-release formulations, which are described in official documents. These different versions provide flexible dosing options for patients and allow for both short-acting and long-acting needs for cough relief.


Q: Does Stopex stay in your system for a long time?

According to pharmacokinetic data, the time it takes for Stopex to be completely cleared from the body varies by individual. The medicine is typically eliminated within 24 to 48 hours, but in some people, it may remain detectable for 72 hours or longer due to differences in metabolism.


Q: What should I tell a new doctor about Stopex?

Official guidelines strongly recommend informing all healthcare providers, including doctors, nurses, pharmacists, and dentists, about all medicines being taken. This includes Stopex, as well as any vitamins, herbal products, and supplements, to help avoid potential interactions.


Q: Can Stopex affect the results of lab tests?

Official warnings indicate that high doses of Stopex may affect the results of certain laboratory tests. Specifically, misuse of the medicine has been associated with a false-positive result for Phencyclidine (PCP) and/or opiates on some drug screening tests.


Q: What are common patient expectations when starting Stopex?

Patients can generally expect the cough-suppressing effect to start within 15 to 30 minutes and to last for several hours. While not common, it is possible to experience mild, temporary side effects such as drowsiness or dizziness.


Q: What is the purpose of the black box warning on Stopex?

The most serious regulatory warnings are intended to highlight the significant risks associated with the medicine. These warnings call attention to the risks of misuse and overdose, as well as the potential for severe side effects like Serotonin Syndrome when Stopex is combined with specific contraindicated medicines.


Q: Is Stopex used outside of the United States?

Yes, the active ingredient in Stopex, Dextromethorphan, is widely approved and used in many countries worldwide. However, the specific regulations regarding its dosage, availability, and labeling may vary between different regions.

How should Stopex be stored and disposed of?

Stopex Storage and Disposal Requirements

The storage of Stopex (Dextromethorphan Hydrobromide) must adhere to the official requirement of controlled room temperature, maintaining a range between 20 C and 25 C (68 F and 77 F). The product must be protected from both moisture and excessive heat to preserve its stability.

Packaging and Safety

The medicine must be kept tightly closed in its original container. A critical safety requirement is to store Stopex out of the reach of children.

Disposal Instructions

Disposal of unused or expired medication must be conducted properly and according to local regulations. Individuals are instructed not to flush the product down the toilet or pour it into a drain unless explicitly directed by a regulatory program.

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

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