Theophylline (Oral)

As a bronchodilator, theophylline helps muscles in the bronchial tubes to relax and improve the flow of air around the lungs.


Theophylline is a bronchodilator, which is the name given to medications which help the muscles in certain parts of the lungs to work. They work by helping the bronchial tubes (also known as air passages) to relax, which means there's more air available in the lungs. This can help cut down on the symptoms of many lung conditions, such as wheezing, an inability to catch the breath and constant coughing.

Taken orally, this medication is only available with a prescription from a physician and cannot be bought over the counter. Oral theophylline has a number of different brand names in the US, and you may see it referred to in this way in stores and pharmacies. These are Elixophyllin, Norphyl, Phyllocontin, Quibron-T, Quibron-TSR, Theo-24, TheoCap, Theochron, Theo-Dur, Theo-Time, Truxophyllin and Uniphyl.

Oral theophylline comes in a wide variety of medicine formats, and your physician will advise which one is right for you based on your medical situation and history. You can take this medicine as a standard tablet, or as a tablet with extended release, a 12-hour extended release or a 24-hour extended release. You can also take it as an enteric-coated tablet, which means the tablet will be harder to disintegrate once it hits your stomach. In addition, you can take this medication as a capsule with similar extended release options, or as a syrup, elixir or solution. If you would like to take your oral theophylline in a certain way, you should consult your doctor.

Condition(s) treated

Type of medicine

  • Bronchodilator

Side effects

As with many drugs, taking oral theophylline can result in unpleasant side effects, as well as relief from the original symptoms. Often, the side effects are a difficult but necessary part of getting better.

It cannot always be predicted what sort of side effects a person is likely to experience, and often it can vary from patient to patient. If you have any specific concerns about the side effects of this drug, you should speak to your physician or another healthcare professional to find out more.

With oral theophylline, the potential side effects of the drug can broadly be split into three different categories. The first of these categories is a group of side effects which may be symptoms of overdose, and as a result, these are the most serious. If you experience any of these side effects, you should go to the emergency room or seek urgent medical help right away. Once there, you or someone who is accompanying you should make it clear to the emergency medical staff that you are taking oral theophylline.

The symptoms included in this set of side effects are diverse. They include a range of issues related to toilet functions, such as urine with an unusually dark color, a decrease in the frequency or amount of urine or the ability to pass it without difficulty or pain, and diarrhea. Digestion issues can also reveal symptoms of overdose, such as pain in the abdomen or stomach, and nausea or being sick - in particular, vomiting up a substance with blood in it or a substance which resembles ground coffee.

Problems with the organs around the face and head can also indicate symptoms of overdose, and hence should be treated as serious side effects. These include problems with your eyesight, such as blurred vision. Issues with your mouth can also be a warning sign, such as dryness, feeling more thirsty than usual or a tingling sensation in your lips.

Some of the serious side effects associated with taking oral theophylline are mental in nature. These include experiencing confusion, mood changes, nervousness or a feeling of fatigue. Do not consider mental side effects to be any less important than physical side effects, and visit your doctor right away if you experience any of these issues.

This is not an exhaustive list of potential serious side effects, so you should always take the time to familiarise yourself with the full list to prevent problems further down the line. This is often available in the information booklet you receive alongside your theophylline medication.

The next category of possible side effects you may experience as a result of taking oral theophylline are those for which you should seek help from a doctor if you experience them, but are not emergency-level. These include a wide range of symptoms related to your vital organs, including chest discomfort or a heartbeat that is particularly fast, slow or irregular. If you find yourself experiencing lightheadedness or shakes, for example, you should again seek medical advice.

While a decrease in your level of urine is a serious side effect requiring emergency treatment, an increase in the volume of your urine is not an emergency level side effect. You should consult your doctor if this happens to you.

Finally, there are some side effects which can arise as a result of taking oral theophylline which do not ordinarily require medical attention. Should you experience any of these side effects, you can usually simply wait until they go away naturally. If that does not happen, speak to your physician or healthcare professional. They might be able to advise you on some methods of reducing these side effects and put your mind at rest.

In this category, symptoms like irritability and restlessness are included. Headaches are also part of this category, as are a range of sleep problems such as sleeplessness or a pronounced difficulty in falling to sleep.


When it comes to your dosages of oral theophylline, you should always follow the instructions given to you by your healthcare professional. It's vital that you do this, as the experience and needs of one patient is often different to that of another. The dosages given here are simply guidelines to give you an idea of what to expect, rather than a configuration designed specifically for you.

The standard dosages of oral theophylline vary greatly based on the format of the drug, weight of the patient, and more.

Firstly, for those taking the drug as elixir or standard (non extended-release) tablets, the oral dosage is usually between 300 and 600 milligrams (mg) per day divided up into smaller doses to be taken every six to eight hours or so. This applies to all people over the age of one who weigh over 45 kilograms (kg).

Children who are aged between one and 15 years of age and who also weigh less than 45 kg will be treated differently. The dosage of oral theophylline they will take will depend entirely on their body weight. The first daily dose for this patient group will be between 12 and 14 mg for every kilogram of body weight, divided into smaller doses and delivered once every four to six hours or so.

For infants aged less than one years old, the exact dosage will vary and will be determined by your child's physician.

For those adults and children aged 12 or older and weighing over 45 kg taking oral theophylline as an extended-release capsule, the standard dosage will be different. The initial dosage will often be between 300 mg and 400mg once a day, although sometimes the dose can be divided into two and given twice per day. For this group, the total daily dose will often be capped at 600 mg - but for older adults, the upper limit tends to be 400 mg.

For children and teenagers in the specific 12 to 15 years age group and who weigh less than 45 kg, the daily dose of 12 to 14 mg per kilogram of body weight still applies. Usually, the dose should be taken once a day, or split into two and given twice at most.

For those aged less than 12 years old, a physician must determine the dosage.

Finally, for those taking extended-release tablets - rather than capsules - the standard dosages can again be different. Those aged over six years old and weighing more than 45 kg often receive a dosage of 300 mg divided into two and given once every 12 hours. And again, for older adults, the dosage will often be capped at 400 mg, while for others in this group the cap is 600 mg.

Children and teenagers in the specific six to 15 years age group and who weigh under 45 kg are again likely to see a daily dose of 12 to 14 mg per kilogram of body weight. The extended-release tablets will usually need to be divided and given every 12 hours.

Those under six will usually have their dosage determined by their physician.

In the event that you miss a dose of oral theophylline, you should make your decision about what to do around what time it is. Check the time first, then work out how long it is until your next dose is due as per your normal dosing schedule. If your next dose is a long time away, you can go ahead and take the oral theophylline dose you missed. If your next dose is impending or due to take place in a short space of time from now, however, you should skip the dose you missed and then return to your normal schedule. You should never take a double dose of oral theophylline, even if you missed one.


Medications contain a number of powerful ingredients designed to relieve symptoms when an illness is present. One consequence of this is that the two drugs you take can interact with each other to the point that they cause you further problems.

Your physician will make a decision about whether to prevent you from taking certain medications or alter the dosage depending on any other drugs you take. However, they cannot make an accurate judgement about this without first having all the information they need about your condition. That's why it's vital that you keep track of all the medications you take and ensure that this up to date, accurate list is shared with your physician.

There are a small number of medications which usually will not be prescribed alongside oral theophylline because of the potential for serious interactions to take place. These include amifampridine, a rare drug used to treat Lambert-Eaton myasthenic syndrome, and riociguat, which treats pulmonary arterial hypertension.

There is a wide range of other drugs which can cause interactions serious enough to merit reconsideration of your current medication arrangements when they are used with oral theophylline. Medications in this category include dihydroartemisinin, ethynodiol diacetate, idrocilamide, ciprofloxacin and norgestimate. Also included on this list is siltuximab, adenosine and cimetidine.

In addition to this, there are also some drugs which can cause interactions when used with oral theophylline, but these interactions are not usually serious enough to alter your current medication arrangements. These drugs include a number of medicinal drugs, such as chlordiazepoxide, disulfiram, nilutamide, flunitrazepam and rifampin. Also affected are halazepam, lormetazepam, riluzole and isoproterenol, and also included on this list are some drugs which are herbal in nature or can be used recreationally. This includes St John's Wort and cannabis.

This is not an exhaustive list, which is another reason why it is important to ensure that your physician and other healthcare professionals are aware of all your current drugs.

In addition to interactions with other medicines, oral theophylline can interact with a number of other consumption options such as foodstuffs or drinks.

In most circumstances, your physician will advise against taking oral theophylline alongside smoking tobacco. You should be honest with your doctor about your smoking habits and your potential for not using tobacco while taking these drugs. In the event that oral theophylline will continue to be used in conjunction with tobacco, you may find that your physician will alter your dosage.

In addition, oral theophylline can interact with certain foodstuffs or the drug caffeine, which is found in many drinks such as coffee. For that reason, your physician may give you a set of instructions which you should follow.

Finally, some pre-existing illnesses may also interact with oral theophylline. Your physician should have your up to date medical notes and therefore be able to identify any problems.

The diseases on the list include congestive heart failure, high fever (102 degrees Fahrenheit or over for a day or more), liver disease, heart rhythm problems and more. This is not an exhaustive list.


Oral theophylline comes with a number of warnings, and even after the appointment with your physician, it's important to familiarise yourself with the list before taking the drug.

While it's likely that not all of the warnings associated with oral theophylline will apply to you, you should always check the full list to prevent the likelihood of missing something relevant to your own health and medical situation.

If you go to take a medical test while taking oral theophylline, you should be aware that the medication can affect the outcomes of some tests and distort the picture of your health which the test produces. Tell the team leading the test that you're taking oral theophylline before the test begins.

You should not stop taking this medicine unless you have checked first with your physician or healthcare professional and they have advised that this is a good idea.

The full list of warnings should be included in the literature which comes inside the packaging of your oral theophylline, such as the information booklet. You should keep this information, as you may need to refer to it at some point in the future.

While taking oral theophylline, you should be sure not to take other medications simultaneously without checking first with your physician. This includes over the counter drugs - such as cough and cold remedies - as well as other prescription medications.


As with any medication, it's vital that you keep your oral theophylline in a safe environment to prevent it from becoming damaged, lost or accidentally consumed.

Firstly, ensure that medications are out of the reach of children. Even if you don't have children living in your home, it's important that even children who happen to visit aren't ever able to access your medication and accidentally consume it.

Secondly, you should ensure that you keep your oral theophylline well away from adverse environmental conditions, such as sources of heat and moisture. You should also ensure that your oral theophylline is not stored in a direct stream of light. Do not freeze your oral theophylline.

Finally, you should make sure that you throw away your oral theophylline when you have finished the course prescribed by your doctor, even if there are some doses you are not supposed to take still left in the packaging. If you don't know how to do this, you should speak to your healthcare professional to find out more about how you can dispose of medication appropriately.

If you opt for the syrup version of oral theophylline, you should ensure that the cap is screwed on securely at all times. This will prevent accidental spillage and enure you don't lose a dose to leaking.


Oral theophylline is designed to help those who suffer from conditions affecting their lungs to breathe more normally. As a bronchodilator, the drug helps to improve airflow to the lungs, which in turns enables easier breathing. Ultimately, this helps to cut down on wheezing, coughing and more.

Oral theophylline has a number of brand names in the USA, including Elixophyllin, Norphyl and more. It is only available with a prescription and can be taken in a wide range of formats including elixir, tablet, capsule and syrup.

A number of side effects are associated with oral theophylline. Some of these are serious and require emergency medical attention, such as urine of a dark color, difficulty urinating, blurred vision and confusion. Other side effects are less serious and simply require you to see a doctor at some point soon, including lightheadedness and shakes. Finally, some of the side effects associated with oral theophylline usually go away within a few days and only require a visit to the doctor in the event that the symptoms persist or are causing you problems. These effects include irritability and sleep disorders.

There are standard dosage guidelines for oral theophylline, although these can vary based on your physician's advice. For many people, the dosage will begin at around 300 mg and end at a maximum of 600 mg, although this can vary based on a wide range of factors such as age, body weight and more. The number of doses per day can also vary based on factors like these.

This medication can interact with a range of other medications. Some, such as amifampridine and riociguat, will usually not be prescribed alongside oral theophylline. Others, such as idrocilamide and ciprofloxacin, will often be prescribed alongside a change in dosage or an alteration of the configurations of your current medication.

Oral theophylline can also interact with a range of other consumable items, such as St John's Wort and alcohol. You should always keep a full, accurate and up to date list of your current medications both to hand and in your medical notes in order to make sure your physician knows what you are currently taking.

Your oral theophylline medication comes with a number of warnings, and you should always familiarise yourself with these before going ahead with the course of treatment. For example, if you take a medical test while on a course of oral theophylline the results may be distorted, so you should inform the staff leading the test.

Always store your oral theophylline in a safe place where children cannot accidentally access it, and dispose of any unused medication in an appropriate manner. If you are unsure how to do this, consult your medical team.

Last Reviewed:
December 24, 2017
Last Updated:
April 03, 2018
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