Generic Theo-24 Sr

Introduction

Theo‑24 Sr is a long‑acting oral formulation of the methylxanthine theophylline, classified within the asthma medication group. In the United Kingdom it is prescribed primarily for chronic obstructive pulmonary disease (COPD) and for the maintenance treatment of asthma when inhaled therapies alone are insufficient. Theophylline exerts bronchodilatory and anti‑inflammatory actions, making it valuable as an adjunct to inhaled corticosteroids and β₂‑agonists.

What is Theo‑24 Sr?

Theo‑24 Sr is a sustained‑release tablet containing theophylline as the sole active pharmaceutical ingredient. It is manufactured by a licensed pharmaceutical company (the specific producer may vary according to the supply chain). The preparation is designed to release theophylline gradually over a 24‑hour period, allowing once‑daily dosing.

The drug belongs to the methyl‑xanthine class, a group of compounds that have been used for more than six decades to manage obstructive airway disease. Its formulation as a prolonged‑release tablet distinguishes it from immediate‑release theophylline products, reducing the frequency of dosing and smoothing fluctuations in plasma concentration.

How Theo‑24 Sr Works

Theophylline competitively inhibits phosphodiesterase (PDE) enzymes, principally PDE III and PDE IV, leading to increased intracellular cyclic adenosine monophosphate (cAMP). Elevated cAMP relaxes bronchial smooth muscle, producing bronchodilation.

In addition to PDE inhibition, theophylline blocks adenosine receptors (A₁, A₂A) that mediate bronchoconstriction and inflammatory cell activation. This dual mechanism contributes to modest anti‑inflammatory effects, such as reduced release of cytokines (e.g., tumor necrosis factor‑α, interleukin‑8) from airway macrophages.

Because the drug is released over 24 hours, steady‑state plasma concentrations are achieved after 3–5 days of regular dosing. The therapeutic window for theophylline is narrow (typically 10–20 µg/mL), and the sustained‑release design helps maintain concentrations within this range while minimizing peaks that are associated with toxicity.

Conditions Treated with Theo‑24 Sr

• Chronic Obstructive Pulmonary Disease (COPD) – Theophylline improves exercise tolerance and reduces exacerbation frequency when added to inhaled bronchodilators. In the UK, COPD affects an estimated 1.2 million adults, making adjunctive therapy clinically relevant.
• Persistent Asthma – For patients whose asthma remains uncontrolled despite optimal inhaled corticosteroid/long‑acting β₂‑agonist (ICS/LABA) therapy, theophylline can provide additional bronchodilation. Approximately 450 000 adults in the UK have severe asthma that may benefit from add‑on agents.
• Bronchiectasis (off‑label) – Some clinical guidelines recognise theophylline as a possible adjunct to improve mucus clearance, although robust evidence is limited.

The drug is not indicated for acute bronchospasm; rapid‑acting inhaled bronchodilators remain the standard of care in that setting.

Who is Theo‑24 Sr For?

• Adults with moderate‑to‑severe COPD who experience persistent symptoms (dyspnoea, limited activity) despite long‑acting inhalers.
• Patients with persistent asthma whose disease remains uncontrolled after adherence to high‑dose inhaled therapy, and who have no contraindications to methyl‑xanthines.
• Individuals who prefer once‑daily oral therapy because of difficulty using inhaler devices (e.g severe arthritis, neuromuscular disorders).
• Patients requiring a cost‑effective adjunct; generic theophylline is typically cheaper than newer oral add‑on biologics.

Contra‑indications include uncontrolled cardiac arrhythmia, recent myocardial infarction, active epilepsy, and severe liver impairment. Caution is advised in the elderly, in patients with renal dysfunction, and in those taking interacting medications (see Interactions section).

Risks, Side Effects, and Interactions

Common

• Nause, vomiting, or anorexia
• Headache
• Insomnia or restlessness
• Palpitations (mild tachycardia)
• Tremor

These adverse events often correlate with plasma theophylline concentrations near the upper therapeutic limit and may resolve after dose adjustment.

Rare

• Hypotension or marked bradycardia
• Visual disturbances (blurred vision)
• Skin rash or urticaria
• Elevated liver enzymes

Rare events typically arise from idiosyncratic hypersensitivity or from drug interactions that raise plasma levels substantially.

Serious

• Seizures (particularly at concentrations > 30 µg/mL)
• Life‑threatening arrhythmias, including ventricular tachycardia or atrial fibrillation
• Severe hypotension or cardiovascular collapse

Any sign of serious toxicity warrants immediate medical assessment, measurement of serum theophylline, and appropriate emergency treatment.

Drug–Drug Interactions

• CYP1A2 inhibitors (e.g., ciprofloxacin, fluvoxamine, cimetidine) markedly increase theophylline levels; dose reduction or close therapeutic drug monitoring (TDM) is required.
• CYP1A2 inducers (e.g., smoking, carbamazepine, rifampicin) lower concentrations, potentially necessitating dose escalation.
• Macrolide antibiotics (erythromycin, clarithromycin) may increase theophylline levels modestly.
• Phenytoin and phenobarbital can reduce plasma concentrations.
• Theophylline may potentiate the effects of other CNS stimulants (e.g., caffeine, ephedrine).

Patients should disclose all prescribed, over‑the‑counter, and herbal products to their healthcare provider.

Practical Use: Dosing, Missed Dose, Overdose

• Starting dose: Adults typically begin with 200–300 mg once daily; the exact dose is individualized based on age, weight, liver and renal function, and concomitant medications.
• Maintenance dose: Adjusted to achieve a serum concentration of 10–20 µg/mL, usually 300–600 mg per day in sustained‑release form.
• Administration: Swallow the tablet whole with a full glass of water; crushing or chewing defeats the extended‑release matrix and may cause toxicity.
• Missed dose: If the scheduled dose is remembered within 6 hours, take it immediately. If more than 6 hours have elapsed, skip the missed dose and resume the regular schedule—do not double‑dose.
• Overdose: Symptoms may include severe nausea, vomiting, tremor, seizures, and cardiac arrhythmias. Seek emergency medical care promptly; treatment may involve activated charcoal (if ingestion is recent), intravenous benzodiazepines for seizures, and cardiac monitoring.

Precautions

• Avoid excessive caffeine, which may add to stimulant effects.
• Alcohol can increase the risk of gastric irritation and central nervous system side effects.
• Renal or hepatic impairment requires dose reduction and more frequent serum level checks.

Buying Theo‑24 Sr from Our Online Pharmacy

Theo‑24 Sr can be obtained safely through our online pharmacy in the UK. We operate as a pharmacy‑broker service that partners with internationally licensed suppliers to source high‑quality generic medicines at prices close to the manufacturer’s cost.

• Affordable pricing – By bypassing intermediate mark‑ups, we pass the savings directly to you, making long‑term therapy more financially sustainable.
• Verified quality – All batches are sourced from GMP‑certified facilities and undergo third‑party testing for potency, purity, and stability.
• Guaranteed delivery – Discreet packaging is dispatched via express courier (delivery within 7 days) or regular airmail (approximately 3 weeks), with tracking available for every order.
• Online‑only access – Our platform provides a convenient channel for patients who encounter limited stock or long waiting times at local pharmacies, especially for medications less commonly stocked.

We respect patient privacy; all shipments are packaged without promotional material, and personal data is protected in accordance with UK GDPR regulations.

FAQ

• What distinguishes Theo‑24 Sr from immediate‑release theophylline tablets?
  Theo‑24 Sr uses a matrix‑based sustained‑release technology that delivers theophylline steadily over 24 hours, permitting once‑daily dosing and reducing peak‑related side effects. Immediate‑release formulations require multiple doses per day, leading to larger concentration swings.

• Can Theo‑24 Sr be taken with food or should it be taken on an empty stomach?
  The tablet can be taken with or without food. Consuming a high‑fat meal may slightly delay absorption but does not significantly affect overall exposure. Maintaining a consistent routine (e.g., same time each day) helps keep plasma levels stable.

• How should the medication be stored during travel abroad?
  Keep the tablets in their original container, stored at room temperature (15 – 25 °C) away from direct sunlight and moisture. If traveling for extended periods, avoid extreme temperatures such as those found in parked cars or suitcases left in hot climates.

• What are the inactive ingredients in Theo‑24 Sr tablets?
  Typical excipients include microcrystalline cellulose, lactose monohydrate, magnesium stearate, and hydroxypropyl methylcellulose as the release matrix. Specific formulations may vary between manufacturers, and patients with known excipient allergies should verify the exact composition.

• Is therapeutic drug monitoring (TDM) required for all patients?
  While routine TDM is not mandatory for every individual, it is strongly recommended when initiating therapy, after dose changes, in the presence of interacting drugs, or in patients with hepatic or renal impairment. Target serum concentrations are 10–20 µg/mL.

• Can Theo‑24 Sr be used during pregnancy or breastfeeding?
  Theophylline crosses the placenta and is excreted in breast milk. It is classified as Pregnancy Category C in the UK, indicating potential risk; use only if the potential benefit justifies the risk. Breastfeeding mothers should discuss the medication with a healthcare professional, as neonatal theophylline levels can be significant.

• Why might smokers require a higher dose of Theo‑24 Sr?
  Cigarette smoke induces CYP1A2, the primary enzyme metabolising theophylline, accelerating clearance and lowering plasma concentrations. Consequently, smokers often need a higher maintenance dose to achieve therapeutic levels.

• Are there any known differences in formulation between the UK and other regions?
  The core active ingredient (theophylline) remains the same, but tablet size, colour, and specific excipients can differ between EU/UK and Asian manufacturers. These differences do not generally affect efficacy but may alter tolerability in patients sensitive to certain fillers.

• What precautions should patients with cardiac disease take?
  Since theophylline can provoke tachyarrhythmias, patients with uncontrolled arrhythmias, recent myocardial infarction, or severe heart failure should avoid Theo‑24 Sr or use it only under strict cardiology supervision with regular ECG monitoring.

• Does Theo‑24 Sr affect common drug‑testing programmes (e.g., workplace testing)?
  Theophylline is not a prohibited or flagged substance in standard occupational drug‑screening panels. However, patients participating in specialized clinical trials should disclose all medications to the trial coordinator.

Glossary

Phosphodiesterase (PDE) inhibition

The process by which a drug blocks the enzyme that breaks down cyclic AMP, leading to prolonged smooth‑muscle relaxation in the airways.

Therapeutic window

The plasma concentration range in which a medication is effective without causing unacceptable toxicity; for theophylline this is usually 10–20 µg/mL.

Sustained‑release (SR) matrix

A tablet formulation that embeds the drug in a polymeric structure, allowing gradual dissolution and absorption over an extended period, typically 24 hours for Theo‑24 Sr.

CYP1A2 induction/inhibition

The increase (induction) or decrease (inhibition) of activity of the cytochrome P450 1A2 enzyme, which can respectively lower or raise levels of medicines metabolised by this pathway, such as theophylline.

⚠️ Disclaimer

The information provided about Theo‑24 Sr is for general knowledge only. It does not replace professional medical consultation. All treatment decisions should be made under the supervision of a qualified healthcare provider. We assume all readers are responsible adults capable of making informed decisions about their health. Our online pharmacy offers access to Theo‑24 Sr for individuals who may have limited availability through traditional pharmacies, prescription‑based insurance schemes, or who are seeking affordable generic alternatives. Always consult your doctor before starting, changing, or discontinuing any medication.