Skip to main content

Tedral (Oral)

Generic name: theophylline, ephedrine, and phenobarbital (oral route)
Drug class: Antiasthmatic combinations

thee-OF-i-lin, e-FED-rin hye-droe-KLOR-ide, fee-noe-BAR-bi-tal

Commonly used brand name(s)

In Canada

  • Tedral

Available Dosage Forms:

  • Tablet
  • Tablet, Extended Release

Therapeutic Class: Bronchodilator, Xanthine Combination

Pharmacologic Class: Ephedrine

Chemical Class: Methylxanthine

Uses For Tedral

Theophylline, ephedrine, and phenobarbital combination is used to treat the symptoms of bronchial asthma, asthmatic bronchitis, and other lung diseases. This medicine relieves cough, wheezing, shortness of breath, and troubled breathing. It works by opening up the bronchial tubes (air passages) of the lungs and increasing the flow of air through them.

Products containing theophylline, ephedrine, and phenobarbital were withdrawn from the U.S. market by Parke Davis in April, 1993.

Before Using Tedral

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:


Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.


Newborn infants may be especially sensitive to the effects of theophylline, ephedrine, and phenobarbital combination. This may increase the chance of side effects during treatment.


Patients older than 60 years of age may be especially sensitive to the effects of theophylline, ephedrine, and phenobarbital combination. This may increase the chance of side effects during treatment.


Pregnancy Category Explanation
All Trimesters D Studies in pregnant women have demonstrated a risk to the fetus. However, the benefits of therapy in a life threatening situation or a serious disease, may outweigh the potential risk.

Breast Feeding


There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.


Studies in women suggest that this medication poses minimal risk to the infant when used during breastfeeding.

Interactions with Medicines

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.

  • Artemether
  • Boceprevir
  • Cyclopropane
  • Halothane
  • Isocarboxazid
  • Lurasidone
  • Nifedipine
  • Praziquantel
  • Ranolazine
  • Rasagiline
  • Rilpivirine
  • Selegiline
  • Voriconazole

Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

  • Abiraterone Acetate
  • Acenocoumarol
  • Adinazolam
  • Alfentanil
  • Alprazolam
  • Amobarbital
  • Anileridine
  • Anisindione
  • Aprobarbital
  • Axitinib
  • Bortezomib
  • Bosutinib
  • Bromazepam
  • Brotizolam
  • Bupropion
  • Butabarbital
  • Butalbital
  • Cabazitaxel
  • Carisoprodol
  • Chloral Hydrate
  • Chlordiazepoxide
  • Chlorzoxazone
  • Cimetidine
  • Ciprofloxacin
  • Clobazam
  • Clonazepam
  • Clorazepate
  • Clorgyline
  • Cobicistat
  • Codeine
  • Crizotinib
  • Dantrolene
  • Dasatinib
  • Deferasirox
  • Delavirdine
  • Desogestrel
  • Diazepam
  • Dicumarol
  • Dienogest
  • Dronedarone
  • Drospirenone
  • Elvitegravir
  • Enoxacin
  • Enzalutamide
  • Erlotinib
  • Erythromycin
  • Estazolam
  • Estradiol Cypionate
  • Estradiol Valerate
  • Ethchlorvynol
  • Ethinyl Estradiol
  • Ethynodiol Diacetate
  • Etintidine
  • Etonogestrel
  • Etravirine
  • Everolimus
  • Fentanyl
  • Flunitrazepam
  • Flurazepam
  • Fluvoxamine
  • Furazolidone
  • Halazepam
  • Halothane
  • Hydrocodone
  • Hydromorphone
  • Idrocilamide
  • Ifosfamide
  • Imatinib
  • Imipenem
  • Iproniazid
  • Irinotecan
  • Ivacaftor
  • Ixabepilone
  • Ketazolam
  • Ketorolac
  • Lapatinib
  • Levofloxacin
  • Levonorgestrel
  • Levorphanol
  • Linagliptin
  • Lopinavir
  • Lorazepam
  • Lormetazepam
  • Maraviroc
  • Medazepam
  • Medroxyprogesterone Acetate
  • Meperidine
  • Mephenesin
  • Mephobarbital
  • Meprobamate
  • Mestranol
  • Metaxalone
  • Methocarbamol
  • Methohexital
  • Methoxyflurane
  • Mexiletine
  • Midazolam
  • Midodrine
  • Mifepristone
  • Morphine
  • Morphine Sulfate Liposome
  • Naproxen
  • Nialamide
  • Nilotinib
  • Nimodipine
  • Nitrazepam
  • Nordazepam
  • Norelgestromin
  • Norethindrone
  • Norgestimate
  • Norgestrel
  • Oxazepam
  • Oxycodone
  • Oxymorphone
  • Pargyline
  • Pefloxacin
  • Peginterferon Alfa-2a
  • Pentobarbital
  • Phenelzine
  • Phenindione
  • Phenobarbital
  • Phenprocoumon
  • Prazepam
  • Primidone
  • Procarbazine
  • Propoxyphene
  • Quazepam
  • Quetiapine
  • Remifentanil
  • Rivaroxaban
  • Rofecoxib
  • Roflumilast
  • Romidepsin
  • Secobarbital
  • Sirolimus
  • Sodium Oxybate
  • Sufentanil
  • Sunitinib
  • Tacrolimus
  • Tapentadol
  • Temazepam
  • Temsirolimus
  • Teniposide
  • Thiabendazole
  • Thiopental
  • Ticagrelor
  • Tolvaptan
  • Tranylcypromine
  • Triazolam
  • Troleandomycin
  • Vandetanib
  • Vemurafenib
  • Vincristine Sulfate
  • Vincristine Sulfate Liposome
  • Zileuton
  • Zolpidem

Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

  • Adenosine
  • Adinazolam
  • Alprazolam
  • Aminoglutethimide
  • Amiodarone
  • Amprenavir
  • Azithromycin
  • Betamethasone
  • Bexarotene
  • Bromazepam
  • Brotizolam
  • Cannabis
  • Carbamazepine
  • Chlordiazepoxide
  • Chlorpromazine
  • Clobazam
  • Clonazepam
  • Clorazepate
  • Clozapine
  • Cortisone
  • Desogestrel
  • Dexamethasone
  • Diazepam
  • Dienogest
  • Digitoxin
  • Disulfiram
  • Drospirenone
  • Estazolam
  • Estradiol Cypionate
  • Estradiol Valerate
  • Ethinyl Estradiol
  • Ethosuximide
  • Ethynodiol Diacetate
  • Etonogestrel
  • Febuxostat
  • Felodipine
  • Flunitrazepam
  • Flurazepam
  • Fosphenytoin
  • Ginkgo
  • Granisetron
  • Griseofulvin
  • Halazepam
  • Interferon Alfa-2a
  • Ipriflavone
  • Isoproterenol
  • Itraconazole
  • Ketazolam
  • Lamotrigine
  • Leucovorin
  • Levomethadyl
  • Levonorgestrel
  • Lorazepam
  • Lormetazepam
  • Medazepam
  • Medroxyprogesterone Acetate
  • Mestranol
  • Methotrexate
  • Methylprednisolone
  • Metoprolol
  • Midazolam
  • Nilutamide
  • Nitrazepam
  • Norelgestromin
  • Norethindrone
  • Norgestimate
  • Norgestrel
  • Oxazepam
  • Oxcarbazepine
  • Pancuronium
  • Pentoxifylline
  • Phenobarbital
  • Phenytoin
  • Piperine
  • Prazepam
  • Prednisone
  • Propafenone
  • Quazepam
  • Quinidine
  • Quinine
  • Rifampin
  • Rifapentine
  • Riluzole
  • Risperidone
  • Ritonavir
  • Rufinamide
  • Secobarbital
  • St John's Wort
  • Tacrine
  • Tacrolimus
  • Telithromycin
  • Temazepam
  • Theophylline
  • Thioridazine
  • Tiagabine
  • Ticlopidine
  • Tipranavir
  • Topiramate
  • Triazolam
  • Valproic Acid
  • Verapamil
  • Viloxazine
  • Warfarin
  • Zafirlukast

Interactions with Food/Tobacco/Alcohol

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following may cause an increased risk of certain side effects but may be unavoidable in some cases. If used together, your doctor may change the dose or how often you use this medicine, or give you special instructions about the use of food, alcohol, or tobacco.

  • Caffeine
  • food

Other Medical Problems

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

  • Angle-closure glaucoma or
  • Convulsions (seizures) or
  • Heart or blood vessel disease or
  • High blood pressure or
  • Underactive adrenal gland—May make these conditions worse.
  • Diabetes mellitus—Phenobarbital may make the condition worse; your doctor may need to change the dose of your diabetes medicine.
  • History of drug abuse or
  • Liver disease—The effects of phenobarbital or theophylline may be increased.
  • Kidney disease—The effects of phenobarbital may be increased.
  • Pain—Phenobarbital may cause unusual excitement in the presence of pain.

Proper Use of Tedral

This medicine works best when taken with a glass of water on an empty stomach (either 30 minutes to 1 hour before meals or 2 hours after meals) since that way it will get into the blood sooner. However, in some cases your doctor may want you to take this medicine with meals or right after meals to lessen stomach upset. If you have any questions about how you should be taking this medicine, check with your doctor.

Take this medicine only as directed. Do not take more of it and do not take it more often than recommended on the label, unless otherwise directed by your doctor. To do so may increase the chance of serious side effects. Also, if too much is taken, the phenobarbital in this medicine may become habit-forming.

In order for this medicine to help your medical problem, it must be taken every day in regularly spaced doses as recommended. This is necessary to keep a constant amount of this medicine in the blood. To help keep the amount constant, do not miss any doses.

Make certain your health care professional knows if you are on any special diet, such as a high-protein, low-carbohydrate or low-protein, high-carbohydrate diet.


The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For bronchial asthma, asthmatic bronchitis, and other lung diseases:
    • For oral dosage form (tablets):
      • Adults—1 or 2 tablets every 4 hours.
      • Children weighing more than 27 kilograms (kg)—1/2 or 1 tablet every 4 hours.
      • Children weighing less than 27 kg—Use and dose must be determined by your doctor.

Missed Dose

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.


Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Precautions While Using Tedral

The theophylline in this medicine may add to the central nervous system stimulant effects of caffeine-containing foods or beverages such as chocolate, cocoa, tea, coffee, and cola drinks. Avoid eating or drinking large amounts of these foods or beverages while taking this medicine. If you have any questions about this, check with your doctor.

The phenobarbital in this medicine will add to the effects of alcohol and other CNS depressants (medicines that slow down the nervous system, possibly causing drowsiness). Some examples of CNS depressants are antihistamines or medicine for hay fever, other allergies, or colds; sedatives, tranquilizers, or sleeping medicine; prescription pain medicine or narcotics; other barbiturates; medicine for seizures; muscle relaxants; or anesthetics, including some dental anesthetics. Check with your doctor before taking any of the above while you are using this medicine.

A change in your usual behavior or physical well-being may affect the way this medicine works in your body. Check with your doctor if you:

  • have a fever of 102 °F or higher for at least 24 hours or higher than 100 °F for longer than 24 hours.
  • start or stop smoking.
  • start or stop taking another medicine.
  • change your diet for a long time.

Before you have myocardial perfusion studies (a medical test that shows how well blood is flowing to your heart), tell the medical doctor in charge that you are taking this medicine. The results of the test may be affected by this medicine.

This medicine may cause some people to become dizzy, lightheaded, drowsy, or less alert than they are normally. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are dizzy or are not alert.

Tedral Side Effects

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

Less common or rare
  • Heartburn and/or vomiting
Symptoms of toxicity
  • Abdominal pain, continuing or severe
  • confusion or change in behavior
  • convulsions (seizures)
  • dark or bloody vomit
  • diarrhea
  • dizziness or lightheadedness
  • fast and/or irregular heartbeat, continuing
  • nervousness or restlessness, continuing
  • trembling, continuing

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Less common
  • Chest discomfort or pain
  • drowsiness
  • fast heartbeat
  • headache
  • muscle cramps
  • nausea
  • nervousness or restlessness
  • trembling
  • trouble in sleeping

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

More about ephedrine / phenobarbital / theophylline

Related treatment guides

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.