Theodur (Theophylline SR 12 HR)

Name: Theodur
Brand: Generic
SKU: 2100
Availability: InStock

Type

Product

Manufacturer

Country

Dosage

Qty-Price (USD)

There is no brand product of Theodur.

Generic Equivalent of Theodur

Type

Product

Manufacturer

Country

Dosage

Qty-Price (USD)

Type:

Product: Theophylline SR 12 HR

Manufacturer: Generic

Country: Canada

Dosage: 100 mg

Qty-Price (USD):

Type:

Product: Theophylline SR 12 HR

Manufacturer: Generic

Country: Canada

Dosage: 200 mg

Qty-Price (USD):

Type:

Product: Theophylline SR 12 HR

Manufacturer: Generic

Country: Canada

Dosage: 300 mg

Qty-Price (USD):

Theodur Information

medically reviewed by Dr. HaVy Ngo, Pharmacist on May 16, 2025.

Theophylline SR 12 HR at CanadaPharmacyOnline.com

Brand Theodur is currently unavailable (at this pharmacy).

Generic theophylline SR 12 HR is available in many countries worldwide, including Canada.

It is sourced from manufacturers that meet applicable regulatory standards. The specific manufacturer of your dispensed medication may vary.

Important Information about Generic Theophylline SR 12 HR:

Generic theophylline SR 12 HR contains the same active ingredient as brand-name Theodur and is required to meet the same safety, effectiveness, and quality standards. This means it is designed to work in the same way as Theodur. Studies have demonstrated bioequivalence between generic and brand-name theophylline SR 12 HR, meaning they have comparable absorption rates and overall effects. However, individual responses to any medication can vary. If you have any questions about using generic theophylline SR 12 HR, talk to your doctor or pharmacist.

For more information about generic drug approval and bioequivalence, please refer to Access to Generic Drugs in Canada | Canada.ca

Dosage:

The generic theophylline 12 HR is available as 100 mg, 200 mg, and 300 mg oral extended-release (SR) tablets.

Your doctor will determine the appropriate dosage based on the individual needs and medical conditions.

Usage:

Theodur (theophylline SR 12 HR) is a prescription medication used to treat lung diseases such as asthma and chronic obstructive pulmonary disease (COPD), which includes bronchitis and emphysema. Lung diseases are conditions that affect the lungs, hindering their ability to function appropriately and causing various respiratory problems. These diseases can affect the airways, lung tissue, or blood vessels within the lungs (source: the product labeling information). Theophylline does not work immediately and, thus, should not be used as a rescue inhaler. Use other forms of rescue inhalers for quick relief.

Mechanism of Action:
Theodur (theophylline SR 12 HR) is a bronchodilator. Theodur belongs to the class of medication called Xanthines. It works by relaxing the muscles in the bronchial tubes of the lungs so that they can open up and allow you to breathe easily. It also increases the flow of air through the bronchial tubes and reduces lung response to irritants, thereby relieving you of cough, wheezing, shortness of breath, and breathing troubles. Controlling your asthma or other breathing difficulties allows you to focus on your daily activities and live a healthy life.

Take Theodur exactly as your doctor prescribes, following the instructions in the Drug Label Information | DailyMed. Consult your doctor for personalized guidance and safe use.

The information below summarizes some, but not all, potential side effects, risks, and interactions. Before taking Theodur, it is essential to discuss all potential side effects, risks, and interactions with your doctor or pharmacist.

Side Effects:

The information below is a partial list of side effects; individual reactions can vary. Before starting Theodur, it is crucial to discuss potential side effects and risks with your doctor or pharmacist.

Common side effects – These are examples of some common side effects of Theodur, but others are possible. Contact your doctor promptly if any side effects are persistent, worsening, or concerning or if you experience any other concerning symptoms.
• Abdominal pain
• Diarrhea
• Headache
• Increased urination
• Nausea

Serious or rare side effects – Stop taking Theodur and seek immediate medical attention right away if you experience any of the following:
• Allergic reactions, including angioedema, hives, and trouble breathing
• Confusion
• Fast or slow heartbeat
• Muscle cramps
• Seizures
• Severe nausea and vomiting;

Contraindications:

This is not an exhaustive list of contraindications. It is crucial to discuss all your medical conditions, past and present, and all medications you are taking with your doctor or pharmacist before starting Theodur.

Theodur should not be used if:
• Are allergic to theophylline SR 12 HR or any of the inactive ingredients in Theodur
• You have porphyria
• You have seizure disorders
• You have severe heart conditions
• You have severe hyperthyroidism
• You have severe liver disease or cirrhosis
• You have a stomach ulcer or gastrointestinal bleeding

Tell your doctor about all of your medical conditions, past and present, before starting Theodur. This is crucial because certain conditions can affect whether Theodur is right for you. These conditions may include, but are not limited to:
• Cystic fibrosis
• Heart disease
• Hyperthyroidism
• Kidney disease
• Liver disease
• Peptic ulcer
• Pulmonary edema
• Sepsis

Alcohol:
Drinking alcohol when taking Theodur can increase the side effects of the drug. Limit or avoid alcohol consumption when taking this medicine.

Caffeine:
Caffeine can increase the stimulant effects and side effects of theophylline. Limit the intake of coffee, tea, colas, and chocolate when using this medicine.

Dizziness and Drowsiness:
Theodur may cause dizziness, drowsiness, and blurred vision. Avoid getting up too fast from a sitting or lying position. Otherwise, you may feel dizzy. Avoid driving, operating machinery, or engaging in activities that require alertness until you understand how it affects you.

Grapefruit:
Grapefruit juice can increase the amount of theophylline in your blood, increasing the risk of side effects. You should speak to your doctor if this is of concern to you.

Smoking:
Smoking tobacco or marijuana can significantly affect theophylline levels, usually decreasing them. Dosage adjustments are often necessary, and stopping smoking can lead to increased theophylline levels, requiring further adjustment.

Drug Interactions:

Before taking Theodur, it is essential to discuss all potential risks and interactions with your doctor or pharmacist. For complete information about potential drug interactions, please refer to the product monograph in Canada at https://www.aapharma.ca/downloads/en/PIL/2021/Theo_LA_PM_EN.pdf and discuss any concerns with your healthcare provider.

Provide your doctor with a complete list of all your medications, including prescriptions, over-the-counter (OTC) drugs, vitamins, and herbal supplements. Theodur can interact with other medicines but is not limited to riociguat, abametapir, adenosine, imipenem, cimetidine, desogestrel, phenytoin, erythromycin, St. John’s wort, and midazolam.

Pregnancy and Breastfeeding:

If you are pregnant or become pregnant, tell your doctor before using Theodur. It is unknown if theophylline SR 12 HR will harm an unborn baby. Theophylline levels may change during pregnancy, requiring close monitoring. It is crucial to discuss the risks and benefits of using Theodur with your doctor before taking it. If you are breastfeeding or plan to breastfeed, inform your doctor. It is unknown if theophylline SR 12 HR is excreted in human breast milk. It is crucial to discuss the risks and benefits of using Theodur with your doctor before taking it.

Frequently Asked Questions about Theodur at Canada Pharmacy Online

Why is Theodur more affordable in Canada than in the United States?

Prescription drug prices, including Theodur, are generally lower in Canada than in the US due to a combination of factors, primarily government price regulations, differing market dynamics, and other economic considerations. In Canada, provincial and federal governments negotiate drug prices with pharmaceutical companies, which often results in lower costs compared to the US, where market forces play a more significant role. For more information, see the FAQs on Prescription Drug Importation from the Kaiser Family Foundation (KFF): https://www.kff.org/health-costs/issue-brief/faqs-on-prescription-drug-importation/

Can I cut or split a Theodur tablet?

It is generally not recommended to cut, split, or chew Theodur tablets. Crushing or breaking the tablets can lead to a rapid release of the drug and potentially cause adverse effects.

How much is the shipping?

Our shipping fee is a flat rate of $10.00 per order. Our pharmacy focuses on getting you the lowest prices on high-quality products.

How do I order from your pharmacy?

Ordering from us is very simple. You can purchase online or call Customer Service at 1866.920.3784. For additional information or to learn about the ordering process, visit our How to Order page.

Is there a limit on how many Theodur tablets I am allowed to order at one time?

CanadaPharmacyOnline.com can only dispense a maximum of a three-month supply of Theodur at one time, as per your doctor's prescription.

Can I buy Theodur over the counter from you?

No, Theodur requires a valid prescription from your doctor. We do not sell this product without a valid prescription.

Do you ship to the United States?

Yes, we do. It usually takes between 7 and 18 business days to receive your order from our pharmacy.

What is the difference between Theodur 100 mg, 200 mg, and 300 mg?

The difference in dosage represents the amount of active ingredient(s) present in the drug.

What is the best time to take Theodur?

Take this medicine twice daily, every 12 hours. You can take Theodur with or without food, but you should take it the same way every time (always with food or always without food).

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The information on this page is sourced from independent third parties contracted by CanadaPharmacyOnline. While we cannot guarantee its medical accuracy, we strongly recommend consulting a healthcare professional for personalized advice regarding medications or medical conditions.

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