Thoin

Quick links to important sections

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 Thoin

What is Thoin: Identity, Type, and Composition

Property Description
Active ingredient Choline Theophyllinate (Oxtriphylline)
Form Tablet, syrup, elixir, capsule, solution for nebulization
Pharmacological class Bronchodilator, Xanthine derivative
Common use Facilitating easier breathing by opening airways
Origin Synthetic derivative

Thoin is the trade name for the pharmaceutical compound Choline Theophyllinate (INN), a synthetic derivative classified as a bronchodilator within the xanthine derivative group. This medicine is defined as a chemical salt of the active ingredient Theophylline, combined with Choline to enhance its solubility and systemic absorption. The distinction of being the choline salt is a key differentiating factor, as it is noted for minimizing some of the gastrointestinal distress that can be associated with the traditional Theophylline base. The compound is a single-ingredient product, chemically known by the synonym Oxtriphylline.

Available Forms and General Therapeutic Purpose

Choline Theophyllinate is formulated for oral administration and is available in various pharmaceutical preparations, including tablets, syrups, elixirs, and capsules, alongside specialized solutions for nebulization. The general purpose of this systemic medication is to achieve bronchodilation, which is the relaxation and widening of the smooth muscles that surround the air passages. The availability of the compound in forms like a flavored syrup or elixir is often utilized for patients who require consistent delivery but cannot swallow solid forms.

The core benefit of Thoin is linked to its function as a systemic bronchodilator: by relaxing the constricted bronchial tubes, the medicine generally helps to reduce resistance within the airways, facilitating easier and more effective airflow for the patient, which is a common need during episodes of nighttime wheezing. Theophylline and its derivatives are suitable for the sustained management of conditions involving reversible airways obstruction.

What side effects are possible with Thoin?

Possible Side Effects and Safety Information

The safety profile of Thoin (Choline Theophyllinate) is defined by officially documented adverse reactions that are primarily systemic and concentration-dependent, as classified in regulatory documents for its active constituent, Theophylline.


Officially Documented Adverse Reactions

Side effects are categorized across several System-Organ Classes (SOCs) and are largely related to the medicine's stimulant properties. The most frequently reported reactions are classified as Common and typically involve Gastrointestinal Disorders (Nausea, Vomiting, Diarrhea) and Nervous System/Psychiatric Disorders (Headache, Tremors, Restlessness, Insomnia).

Other effects listed in official labeling include Cardiac Disorders (Rapid or Irregular Heartbeats) and Metabolism and Nutrition Disorders (Hypokalemia, high blood sugar).


Serious Safety Considerations

The most significant risk is related to Concentration-Dependent Toxicity. Regulatory documents explicitly state that the frequency and severity of adverse reactions increase markedly when the medicine's serum concentration exceeds 20,mu g/ mL.

Serious adverse reactions documented in official sources include Seizures (Convulsions) and potentially life-threatening Cardiac Arrhythmias. These are risks particularly associated with high exposure.


Population-Specific Safety Notes

Official labeling identifies specific patient groups requiring caution. Pediatric patients under one year of age are noted as being more likely to experience serious adverse effects. Older adults and individuals with Hepatic Impairment (liver disease) may have slower drug clearance, which increases the risk of toxicity and requires special consideration. Use is officially restricted in patients with a history of Hypersensitivity to theophylline.

Overdose and Emergency Response

Overdose and When to Seek Help

The most serious manifestations of Thoin (Choline Theophyllinate) overdose, which acts as a source of Theophylline, involve severe toxicity to the central nervous and cardiovascular systems. These serious effects are generally documented when serum concentrations exceed 20 mcg/mL.

System Documented Overdose Manifestations
Central Nervous System Seizures, tremors, irritability, restlessness, and ongoing headache.
Cardiovascular Rapid heart rate (tachycardia), irregular heartbeat (ventricular arrhythmias), and hypotension.
Gastrointestinal Severe or continuous vomiting, nausea, and abdominal pain.
Metabolic Hypokalemia (low potassium) and hyperglycemia (high blood sugar).

Life-Threatening Outcomes

The regulatory labeling states that life-threatening symptoms include seizures, which may lead to death or permanent brain damage, and ventricular arrhythmias [1.1, 2.3]. Increased risk of severe complications is noted in patients with hepatic impairment, the elderly, and premature neonates [1.5, 3.6].

Emergency Actions

If overdose is suspected or if severe symptoms such as a seizure, rapid heartbeat, or persistent vomiting occur, immediate emergency medical attention must be sought. Call your local emergency number or the national toll-free Poison Help hotline [2.1, 2.3]. Treatment focuses on supportive care, and no specific antidote is known [2.2, 4.1]. Procedures may involve using activated charcoal to prevent further absorption or administering intravenous benzodiazepines to manage seizures [1.1, 2.2]. Monitoring of vital signs and serum concentration is required [1.1].

Therapeutic Uses of Thoin

What Thoin Treats: Main Uses and Benefits

Thoin (Choline Theophyllinate) is commonly used to help manage symptoms related to various chronic lung diseases. It may be part of symptomatic management to help ease the overall symptom load in conditions involving Bronchial Asthma, Chronic Obstructive Pulmonary Disease (COPD), chronic bronchitis, and emphysema.


Symptomatic Support and Functional Stability

Thoin is generally used as a long-term component in the sustained management of chronic obstructive conditions. It is applied in addressing symptoms related to physical discomfort from narrowed airways, such as chronic wheezing, chest tightness, and persistent shortness of breath. This use supports the patient in efforts to maintain functional stability and contributes to more consistent breathing.

“The medication is considered relevant for supporting patients through the cyclical nature of chronic respiratory symptoms.”

It is particularly relevant for managing breathing issues that tend to worsen during rest, specifically nocturnal wheezing and associated discomfort. In contexts where symptoms are recurrent, this supportive relief contributes to improved day-to-day comfort during symptomatic periods.


Quick Fact: Relief for Airflow Constriction Thoin is considered relevant for easing symptoms that cluster around the physical restriction of airflow within the lungs, and it offers supportive relief that helps patients cope more steadily with symptom fluctuations.

Regulatory References

  1. NIH MedlinePlus overview of Theophylline

Eligibility and Restrictions for Use

Thoin (Choline Theophyllinate) is a xanthine derivative, and its eligibility for use is defined by specific regulatory guidelines that emphasize patient conditions and age, due to known effects on drug metabolism.

Contraindicated Populations

The medicine is absolutely contraindicated (must not be used) in patients with:

  • A known history of hypersensitivity or allergy to any xanthine derivative.
  • Active peptic ulcer disease.
  • Coronary artery disease if myocardial stimulation is judged to be harmful.

Age-Related and Conditional Eligibility

Eligibility is often conditional on close monitoring, as many factors are documented to decrease the drug's clearance, potentially leading to toxicity.

Population Group Eligibility Constraint
Elderly patients (Age > 60 years) Clearance is officially documented as decreased; use requires caution.
Infants (Under 1 year) Require extreme caution due to very low, age-dependent clearance rates.
Liver Impairment Clearance is significantly reduced (e.g., in cirrhosis or acute hepatitis), requiring close monitoring.
Cardiovascular Conditions Restricted use in patients with congestive heart failure or acute pulmonary edema due to decreased clearance.
Pregnancy/Lactation Pregnancy Category C (FDA). Use in the 3rd Trimester requires caution due to reduced clearance. The drug is excreted into human milk.

This structure ensures that most eligible patients with comorbidities or age-related factors receive the medicine only under strict, officially documented conditional use.

What should I know about interactions with other medicines?

Interactions with other medicines and products

The official interaction profile for Thoin (Theophylline) is governed by specific pharmacokinetic alterations and pharmacodynamic risks documented in regulatory labels. Co-administration is formally restricted with agents such as Riociguat, which is not recommended due to a documented risk of additive vasodilation and hypotension.


Metabolic and Exposure Alterations

Theophylline's systemic exposure is highly susceptible to modification by substances that affect its metabolism, primarily via the CYP enzyme system. Ciprofloxacin and other CYP1A2 inhibitors are documented to decrease Theophylline clearance, significantly raising its plasma concentration and increasing the risk of toxicity. Conversely, enzyme inducers such as Rifampin and Carbamazepine accelerate clearance, resulting in decreased systemic exposure. This profile defines the drug's key interaction constraints.


Other Documented Constraints

Pharmacodynamic interactions include an officially noted risk of ventricular arrhythmias when co-administered with Halothane, and antagonism of the sedative effects of Benzodiazepines. Non-medicinal products also interact: Chronic tobacco smoking and alcohol consumption are formally documented to decrease clearance or increase exposure, respectively. Administration requires timing separation from enteral feedings to prevent interference with absorption. Furthermore, the interaction profile is heightened in populations with reduced clearance, such as patients with hepatic impairment, where clearance is documented to be reduced by 50% or more.

Mechanism of Action

How Thoin Works: Pharmacodynamic Mechanism

Thoin's active component, Theophylline, exerts its action through two primary, non-selective molecular mechanisms. The first involves the competitive inhibition of Phosphodiesterase ( PDE) enzymes ( PDE3 and PDE4 isoforms) within airway smooth muscle cells. This inhibition prevents the breakdown of the second messenger, cyclic Adenosine Monophosphate ( cAMP), leading to increased intracellular concentrations. The cAMP buildup initiates a cascade that results in the relaxation of bronchial smooth muscle and a widening of the bronchial lumen.

The second mechanism is the non-selective antagonism of adenosine receptors ( A1, A2 A, A2 B), which blocks adenosine-mediated signals that promote smooth muscle contraction. Additionally, Theophylline functionally modulates Histone Deacetylase 2 ( HDAC2) activity, indirectly suppressing the transcription of pro-inflammatory genes (e.g., TNF-alpha, IL-5). These combined actions result in altered bronchial smooth muscle tone and the modulation of chronic inflammatory gene expression in the airways.

Dosage and Administration Information

Administration and Dosage for Thoin (Theophylline)

Thoin, a bronchodilator of the methylxanthine class, is typically prescribed to manage symptoms associated with reversible airway obstruction, such as asthma and chronic obstructive pulmonary disease (COPD). It relaxes smooth muscle in the airways, increasing air flow to ease breathing. The specific dosage and form of Thoin (e.g., immediate-release tablet, extended-release capsule, or oral solution) are determined by a healthcare provider based on the patient's age, weight, and clinical response.

General Administration Guidelines:

  • Dosage Schedule: Thoin is usually taken every 6, 8, 12, or 24 hours. It is critical to adhere to the prescribed frequency and not take more or less than directed. For sustained-release formulations, maintaining a consistent timing, such as taking the medication at the same time each day, helps keep stable serum concentrations.
  • Oral Forms: Immediate-release and extended-release tablets must be swallowed whole without crushing or chewing, as this could lead to rapid absorption and increased risk of adverse effects. Certain extended-release capsules may be opened, and the contents mixed with soft food before immediate swallowing, without chewing the pellets.
  • Consistency: The drug should be continued as prescribed, even if symptoms improve. Do not stop taking Thoin without consulting a healthcare professional.

Therapeutic Drug Monitoring:

Due to Thoin's narrow therapeutic window, monitoring the drug concentration in the blood is often necessary. A healthcare provider will arrange for periodic blood tests to ensure the concentration remains within the safe and effective range, minimizing the risk of serious side effects. Factors such as diet, smoking status, and other medications can affect how the body processes Thoin, making dose adjustments essential.

Recent Clinical Evidence

Thoin: Recent Clinical Evidence

Clinical research on Thoin primarily focuses on its use in managing chronic respiratory conditions and assessing its overall safety profile. These studies are typically randomized, double-blind, and placebo-controlled to minimize bias and provide robust evidence.

Efficacy in Symptom Management

Studies have investigated whether Thoin shows an association with a reduction in physical discomfort and a change in physiological markers, such as forced expiratory volume in 1 second ( FEV1) and forced vital capacity ( FVC). For instance, a meta-analysis of randomized controlled trials involving patients with chronic obstructive pulmonary disease ( COPD) reported that Thoin was associated with improvements in FEV1, FVC, and PEFR (Peak Expiratory Flow Rate) compared to placebo. It was also noted that treatment was associated with an improvement in the 6-minute walk distance.

Safety and Tolerability

The drug’s safety profile has been a key area of research, particularly in vulnerable populations. Large-scale prospective studies involving older adult patients (age 65) with COPD or asthma assessed safety over periods up to six months. These studies reported a low overall incidence of drug-related adverse events. The most frequently observed adverse events included nausea, loss of appetite, and hyperuricemia. No correlation was noted between the drug's dose and the incidence of adverse events in these patient groups.

Comparative Findings

Comparative research has also examined Thoin against other established treatments. One meta-analysis suggested that certain alternative bronchodilators may be associated with fewer adverse events related to the gastrointestinal system and reduced rates of withdrawal compared to Thoin, although both treatments showed efficacy in managing symptoms.

Frequently Asked Questions (FAQ)

Common questions about Thoin (FAQ)

Q: What makes Thoin different from similar prescription drugs?

Thoin is the trade name for the pharmaceutical compound Choline Theophyllinate. Official product information notes that this specific formulation is the choline salt of the active ingredient, Theophylline. This distinction is referenced in clinical literature for potentially reducing some of the stomach upset and gastrointestinal distress that can be associated with the traditional Theophylline base.

Q: Are there any foods or drinks I should avoid while taking Thoin?

Official patient information notes that limiting or avoiding drinks and foods containing caffeine is often advised while using this medication. Caffeine can increase the levels of theophylline in the blood. This can worsen common side effects, such as feeling nervous, experiencing tremors, or having trouble sleeping.

Q: Is Thoin approved for use in children?

Thoin is approved for use in children aged 1 year and older. Dosage determination for pediatric patients is highly individualized and is based on the child's weight and age according to regulatory guidelines. Extreme caution and special therapeutic monitoring are required when the medicine is used in infants younger than 1 year of age.

Q: Does Thoin affect blood pressure?

Official product information indicates that Theophylline, the active component, may cause changes in heart rate. Regulatory safety data indicates that it has been associated with both increases and decreases in blood pressure, particularly when the serum drug concentrations exceed the normal therapeutic range.

Q: Can Thoin be used for conditions other than its main approved use (clarification question)?

The official approved indications for this medication are limited to treating symptoms associated with reversible airway obstruction, which includes chronic asthma and chronic obstructive pulmonary disease (COPD).

Q: Are there any lifestyle changes recommended while taking Thoin?

Regulatory warnings note that changes in a patient's smoking status can significantly alter the way the body processes theophylline. Official documents emphasize the importance of informing a healthcare provider if a patient starts or stops chronic tobacco smoking, as this change may necessitate a dosage adjustment due to changes in drug clearance.

Q: Is there a generic version of Thoin available? / What is the difference between brand-name Thoin and its generic equivalent?

Yes, the active component of Thoin, Theophylline, is widely available as a generic medication. The generic version contains the same active ingredient and is required by regulatory authorities to meet the same strict standards for quality, strength, and effectiveness as the brand-name product.

Q: How quickly should I expect to notice any effects from Thoin?

For immediate-release formulations, official pharmacokinetics data indicates that the peak level of the medicine in the blood can be expected around 1 to 2 hours after the dose is taken. The speed of effect may vary with the specific formulation and individual factors.

Q: Can Thoin be taken on an empty stomach?

Official documents indicate that immediate-release forms can generally be taken without regard to food. However, extended-release formulations may have a delayed peak drug level if taken with food. Regulatory information emphasizes consistent administration; the specific requirements depend on the formulation type.

Q: Is Thoin safe to take with common vitamins or supplements?

Official patient information highlights the importance of informing a healthcare provider about all current medications they are taking. This includes prescription and over-the-counter medicines, as well as common vitamins and herbal supplements, since these products can potentially affect theophylline blood levels.

Q: What are the long-term safety concerns associated with Thoin? / What happens if I take Thoin for a long period of time?

The official product labeling indicates that Thoin has a narrow therapeutic range, meaning the difference between an effective level and a toxic level is small. For patients receiving long-term therapy, periodic blood tests are typically required for Therapeutic Drug Monitoring to ensure the concentration of the drug remains safe and effective.

Q: How long does Thoin stay in your system after stopping?

The time it takes for the body to eliminate theophylline is highly variable. The half-life, which determines how long the drug stays in the system, is dependent on several factors including age, smoking status, and liver function. Official pharmacokinetics data for healthy, non-smoking adults typically cites a half-life of around 8.7 hours.

Q: Is Thoin considered a controlled substance?

No, according to regulatory classification documents, Thoin (Theophylline) is not categorized as a controlled substance.

Q: What should I do if the side effects of Thoin bother me?

Regulatory safety information states that if signs or symptoms of theophylline toxicity occur, such as unusual or persistent nausea or vomiting, a healthcare provider should be contacted promptly. This action is required so that a serum drug concentration test can be performed and concentration levels managed.

Q: Can I take Thoin if I have kidney issues?

Official documents indicate that clearance may be affected in patients with altered physiological states, such as a severe systemic infection. In these cases, or in infants with pre-existing kidney disease, enhanced monitoring of the drug concentration may be part of the care plan.

Q: Is Thoin known to interact with birth control pills?

Official drug interaction profiles indicate that many medications can affect the concentration of Theophylline in the body. Since certain components of oral contraceptives are known to affect drug-clearing enzymes, a healthcare provider should be kept informed if they are started or stopped, as changes in drug levels may result.

Q: What is the intended duration of treatment with Thoin?

Thoin is used for long-term therapy in some patients to manage chronic respiratory conditions. When treatment is long-term, regulatory guidelines state that periodic blood monitoring of serum theophylline concentrations is required to ensure the drug remains at a safe and effective level.

Q: Does Thoin affect laboratory test results?

Yes, the concentration of Thoin in the blood is often measured using a laboratory test called Therapeutic Drug Monitoring (TDM). This test is done to ensure the drug level is within the safe and effective therapeutic range defined in regulatory documents.

Q: Is Thoin available in different strengths?

Yes, official documentation shows that Thoin (Theophylline) is available in a variety of pharmaceutical preparations. This includes several strengths for extended-release oral formulations, such as 100 mg, 200 mg, 300 mg, and 400 mg capsules or tablets.

Q: What is the typical time frame for Thoin's effects to wear off?

The time frame for the drug's effects to wear off is primarily determined by its half-life. This value is variable but is reported in pharmacokinetics data as around 8.7 hours for healthy adults, and clearance is known to be slower in the elderly and those with liver disease.

Q: Are there any warnings about Thoin and driving or operating machinery?

Regulatory information indicates that because the medicine may cause dizziness or sleepiness, patients are generally advised to use caution and wait until the effects are known before engaging in activities like driving or operating machinery.

Q: Does Thoin interact with common over-the-counter cold medicines?

Regulatory guidance emphasizes the importance of informing a healthcare professional about all concurrent medications, which includes cold and flu medication. These over-the-counter products may contain ingredients that can interact with theophylline.

Q: Is it normal if I feel no difference after starting Thoin?

Official monitoring guidelines acknowledge that some patients may remain symptomatic after starting treatment. In such cases, a serum concentration measurement is needed to determine if the current drug level is 'sub-therapeutic' (too low to be effective) before a dose is adjusted.

Q: Is Thoin a new drug, or has it been around for a while?

Theophylline, the active component, is a well-established bronchodilator and methylxanthine derivative. Clinical history and regulatory approval documents indicate that it has been used in medicine for many years to manage chronic respiratory conditions.

How should Thoin be stored and disposed of?

How to Store and Dispose of Thoin

Thoin (Choline Theophyllinate) must be stored in accordance with the conditions specified in its official regulatory labeling to maintain stability.

Storage Conditions

  • Temperature and Environment: The medicine must be stored at controlled room temperature, generally between 20 C to 25 C (68 F to 77 F). It must be protected from excessive heat, moisture, and light.
  • Protection: The product must remain in its original container. Consistent with federal requirements, the medicine must be kept out of the sight and reach of children and pets.

Disposal Instructions

Disposal of unused or expired Thoin should follow established regulatory procedures. The best option is to use a drug take-back program or an authorized collection site. If no take-back program is available, the medicine should be mixed with an unappealing substance (like dirt or coffee grounds), sealed in a plastic bag, and placed in the household trash. The medicine should not be flushed down a toilet or sink.

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

Available in countries:

Equivalent of Thoin found in:

A-Z Index: