Buy Generic Theophylline Online

Generic Theophylline Information

Introduction

Theophylline is a bronchodilator belonging to the methylxanthine class of drugs. It is prescribed primarily for the management of asthma and chronic obstructive pulmonary disease (COPD) in adult patients. In Hong Kong, Theophylline remains an option when inhaled therapies alone do not achieve adequate symptom control or when oral administration is preferred. The active compound is theophylline itself, and the medication is classified under the asthma‑related drug group. In addition to its respiratory indications, Theophylline is occasionally used off‑label for apnea of prematurity and certain types of bronchopulmonary dysplasia.

What is Theophylline?

Theophylline is a synthetic derivative of caffeine and theobromine. It was first isolated in the early 20th century and introduced as a respiratory therapeutic in the 193s. The drug is marketed worldwide by numerous generic manufacturers; it is not tied to a single brand. Theophylline is the generic version of well‑known brand names such as Theo‑Dur, Slo‑Phyllin, and Elixophyllin, containing the same active compound, theophylline.

Theophylline is the generic version of Theo‑Dur, containing the same active compound Theophylline. Our online pharmacy provides this generic alternative as a cost‑effective treatment option.

The medication is supplied in several oral dosage forms, most commonly immediate‑release tablets (100 mg, 200 mg) and sustained‑release tablets (300 mg, 400 mg). In Hong Kong, both formats are available through licensed pharmacies and can be ordered from our online pharmacy with verified quality assurance.

How Theophylline Works

Theophylline exerts its therapeutic effect through several complementary mechanisms:

• Phosphodiesterase inhibition – By blocking phosphodiesterase‑4 (PDE4), theophylline increases intracellular cyclic adenosine monophosphate (cAMP). Elevated cAMP relaxes bronchial smooth muscle and reduces the release of inflammatory mediators.
• Adenosine receptor antagonism – The drug competitively inhibits adenosine receptors (particularly A1 and A2) in the airway, diminishing bronchoconstriction and cough reflex sensitivity.
• Histamine release moderation – Theophylline stabilises mast cells, leading to a modest reduction in histamine‑mediated airway narrowing.

These actions produce a gradual bronchodilation that begins within 30–60 minutes after oral intake. The effect persists for 6–12 hours with immediate‑release formulations and up to 24 hours with sustained‑release tablets. Theophylline is eliminated primarily by hepatic metabolism via the cytochrome P450 1A2 pathway; clearance can be altered by age, smoking status, liver function, and concurrent drug use, which necessitates therapeutic drug monitoring in certain patients.

Conditions Treated with Theophylline

• Asthma (moderate to severe) – Theophylline is used as an add‑on therapy when inhaled corticosteroids and long‑acting β₂‑agonists (LABA) do not achieve optimal control. In Hong Kong, the prevalence of asthma in adults is approximately 8 %, and a proportion of patients require oral agents to reduce exacerbations.
• Chronic Obstructive Pulmonary Disease (COPD) – For stable COPD, especially when dyspnoea persists despite optimal inhaled therapy, theophylline can improve exercise tolerance and decrease hyperinflation.
• Bronchial hyper‑responsiveness – The drug diminishes airway hyper‑reactivity measured by methacholine challenge, providing clinical benefit in patients with non‑allergic triggers.
• Apnea of prematurity (off‑label) – Low‑dose theophylline stimulates respiratory drive in preterm infants, though this indication is limited to neonatal intensive care settings and not typically managed in adult outpatient practice.

Theophylline’s role has declined in favour of inhaled biologics and combination inhalers, yet it remains a valuable oral option, particularly where inhaler technique is suboptimal or cost constraints limit access to newer agents.

Who is Theophylline For?

• Adults with persistent asthma or COPD who remain symptomatic despite inhaled therapy – Theophylline offers an oral adjunct that can be titrated to achieve additional bronchodilation.
• Patients who have difficulty using inhaler devices – Individuals with arthritis, severe coordination problems, or cognitive impairment may achieve better adherence with an oral.
• Those seeking a low‑cost alternative – Generic theophylline is considerably cheaper than many inhaled combination products, making it attractive for patients with limited insurance coverage in Hong Kong.

Contra‑indications include: known hypersensitivity to methylxanthines, uncontrolled cardiac arrhythmias, severe liver disease, and active peptic ulcer disease. Caution is advised in the elderly, pregnant or lactating women, and patients with epilepsy, as the drug can lower seizure threshold.

Risks, Side Effects, and Interactions

Common

• Nausea, vomiting, or abdominal discomfort
• Headache
• Insomnia or nervousness
• Palpitations or mild tachycardia

Rare

• Diarrhoea or constipation
• Dizziness
• Skin rash or pruritus
• Elevated liver enzymes (transient)

Serious

• Cardiac arrhythmias (e.g., atrial fibrillation, ventricular tachycardia)
• Seizures, especially at serum levels > 20 µg/mL
• Severe hypotension or hypertension
• Life‑threatening allergic reactions (anaphylaxis)

Clinically Relevant Drug–Drug Interactions

• CYP1A2 inhibitors (e.g., ciprofloxacin, fluoroquinolones, cimetidine, oral contraceptives) – increase theophylline serum concentrations, raising toxicity risk.
• CYP1A2 inducers (e.g., smoking, carbamazepine, rifampicin, phenytoin) – lower concentrations, potentially reducing efficacy.
• Beta‑blockers – may blunt bronchodilatory effect.
• Macrolide antibiotics (e.g., erythromycin, clarithromycin) – can increase theophylline levels.
• Antidepressants (e.g., sertraline) – rare reports of increased theophylline toxicity.

Patients should inform their healthcare provider of all current medications, including over‑the‑counter drugs and herbal supplements.

Practical Use: Dosing, Missed Dose, Overdose

• Standard dosing (adults):

  • Immediate‑release tablets: 100–200 mg every 6–8 hours, adjusted to achieve serum concentrations of 10–20 µg/mL.
  • Sustained‑release tablets: 300–400 mg once daily, with dose titration based on clinical response and blood level monitoring.

• Dose adjustment is required in renal or hepatic impairment, the elderly, and smokers (who may need higher doses due to accelerated clearance).

• Missed dose: If a dose is forgotten within 4 hours of the scheduled time, take it immediately. If more than 4 hours have passed, skip the missed dose and resume the regular schedule. Do not double‑dose.

• Overdose: Symptoms may include severe vomiting, seizures, arrhythmias, and respiratory depression. Seek emergency medical care promptly. Activated charcoal can be administered by healthcare professionals if presentation is early.

• Food and alcohol: Theophylline can be taken with or without food; high‑fat meals may delay absorption slightly. Alcohol potentiates central nervous system stimulation and should be limited, as it may increase toxicity.

• Monitoring: Routine serum level measurement is recommended after dose changes, when initiating interacting drugs, or in patients with fluctuating renal/hepatic function.

Buying Theophylline from Our Online Pharmacy

Theophylline is readily obtainable from our online pharmacy in Hong Kong. Our service combines affordability, quality assurance, and discreet delivery:

• Affordable pricing – We source the generic product close to manufacturer cost, passing savings directly to patients.
• Verified quality – All batches are supplied by licensed overseas manufacturers that meet international Good Manufacturing Practice (GMP) standards.
• Guaranteed delivery – Orders are dispatched with discreet packaging; express shipping typically arrives within 7 days, while regular airmail takes about 2‑3 weeks.
• Pharmacy broker model – We collaborate with overseas licensed pharmacies and reputable suppliers, enabling access to medications that may be scarce or expensive locally. Our discreet service respects patient privacy at every step.

Patients in Hong Kong facing limited pharmacy stock, high out‑of‑pocket costs, or insurance restrictions can obtain a reliable supply of generic theophylline through our platform.

FAQ

• Is Theophylline available in both immediate‑release and sustained‑release formulations?
  Yes, Theophylline is marketed as tablets that release the drug quickly (usually 100 mg or 200 mg) and as extended‑release tablets (300 mg or 400 mg) designed for once‑daily dosing. The formulation chosen depends on the physician’s assessment of symptom control and convenience.

• How should Theophylline be stored in Hong Kong’s humid climate?
  The tablets should be kept in a tightly closed container at room temperature, away from moisture, direct sunlight, and heat sources. Using a desiccant packet inside the bottle can help maintain stability in humid environments.

• Can Theophylline be taken together with a daily inhaled corticosteroid?
  Yes, Theophylline is often prescribed as an add‑on to inhaled corticosteroids and long‑acting bronchodilators. No direct pharmacokinetic interaction is known, but patients should be monitored for cumulative side‑effects such as tachycardia.

• Are there any specific warnings for Asian patients taking Theophylline?
  Genetic variations in CYP1A2 activity may affect metabolism, potentially leading to higher serum levels in some Asian individuals. Clinicians often recommend a lower starting dose and early therapeutic drug monitoring.

• What are the typical appearance and markings of generic Theophylline tablets sold online?
  Generic tablets are usually round or oval, scored to facilitate splitting. Imprints differ by manufacturer; common markings include “TH‑100” or “TH‑200” for immediate‑release, and “TH‑300 SR” or “TH‑400 SR” for sustained‑release.

• Does Theophylline require cold storage during transportation?
  No, Theophylline is stable at ambient temperature. Shipping is performed at room temperature, and cold chain logistics are not necessary.

• Can Theophylline be imported for personal use without a prescription in Hong Kong?
  Personal import of prescription‑only medicines is subject to Hong Kong’s customs regulations. Import of Theophylline without a valid prescription may be prohibited, so patients should obtain it through a licensed pharmacy or with appropriate medical documentation.

• What is the impact of smoking on Theophylline therapy?
  Smoking induces CYP1A2, accelerating Theophylline clearance and often requiring higher doses to maintain therapeutic levels. Conversely, cessation can raise serum concentrations, so dose adjustment and monitoring are essential during any change in smoking status.

• How does Theophylline compare to modern biologic therapies for asthma?
  Biologics target specific inflammatory pathways (e.g., IgE, IL‑5) and are highly effective for severe allergic asthma. Theophylline offers a broader, non‑specific bronchodilation and anti‑inflammatory effect but with a narrower therapeutic window. It is less expensive but requires monitoring, making it suitable for certain patients who cannot access biologics.

• What should a patient do if they experience a mild headache after taking Theophylline?
  A mild headache is a common side effect. Patients can try taking the medication with food, ensuring adequate hydration, and avoiding caffeine‑containing drinks, which may exacerbate the symptom. If the headache persists or worsens, they should contact their healthcare provider for possible dose adjustment.

• Is there any difference between Theophylline tablets manufactured in the United States and those produced in Europe or Asia?
  All reputable manufacturers must meet GMP standards, resulting in comparable potency and safety. However, inactive ingredients (excipients) such as fillers or binders may vary by region, potentially affecting tolerability in patients with specific sensitivities.

• Does Theophylline affect results of standard drug tests?
  Theophylline is not typically screened for in routine workplace drug testing. However, it may appear in specialized toxicology panels if specifically requested.

Glossary

Methylxanthine

A class of compounds that includes caffeine, theobromine, and theophylline, characterized by a fused ring structure and central nervous system stimulant properties.

Therapeutic window

The range of drug concentrations in the blood that provides clinical efficacy without causing unacceptable adverse effects. For Theophylline, this window is generally 10–20 µg/mL.

CYP1A2

An enzyme of the cytochrome P450 family responsible for metabolizing many drugs, including Theophylline. Inhibitors or inducers of CYP1A2 can significantly alter theophylline levels.

Bronchodilation

The relaxation of airway smooth muscle, leading to widened air passages and improved airflow.

⚠️ Disclaimer

The information provided about Theophylline 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 Theophylline 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.