Norphyl

Theophylline is used together with other medicines to treat the symptoms of asthma, bronchitis, emphysema, and other lung diseases.

Theophylline belongs to a group of medicines known as bronchodilators. Bronchodilators are medicines that relax the muscles in the bronchial tubes (air passages) of the lungs. They relieve cough, wheezing, shortness of breath, and troubled breathing by increasing the flow of air through the bronchial tubes.

This medicine is available only with your doctor's prescription.

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:

Allergies

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.

Pediatric

Appropriate studies performed to date have not demonstrated pediatric-specific problems that would limit the usefulness of theophylline in children. However, children younger than 1 year of age are more likely to have serious side effects, which may require caution and an adjustment in the dose for patients receiving theophylline.

Geriatric

Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of theophylline in the elderly. However, elderly patients may be more sensitive to the effects of theophylline than younger adults, and are more likely to have kidney, liver, heart, or lung problems, which may require caution and an adjustment in the dose for patients receiving theophylline.

Pregnancy

Breast Feeding

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.

• Amifampridine
• Riociguat

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.

• Adenosine
• Blinatumomab
• Bupropion
• Ceritinib
• Cimetidine
• Ciprofloxacin
• Deferasirox
• Desogestrel
• Dienogest
• Dihydroartemisinin
• Donepezil
• Drospirenone
• Enoxacin
• Erythromycin
• Estradiol Cypionate
• Estradiol Valerate
• Ethinyl Estradiol
• Ethynodiol Diacetate
• Etintidine
• Etonogestrel
• Fluconazole
• Fluvoxamine
• Fosphenytoin
• Golimumab
• Guselkumab
• Halothane
• Idelalisib
• Idrocilamide
• Imipenem
• Levofloxacin
• Levonorgestrel
• Medroxyprogesterone Acetate
• Mestranol
• Mexiletine
• Norelgestromin
• Norethindrone
• Norgestimate
• Norgestrel
• Pefloxacin
• Peginterferon Alfa-2a
• Peginterferon Alfa-2b
• Phenytoin
• Pixantrone
• Regadenoson
• Rofecoxib
• Secukinumab
• Thiabendazole
• Troleandomycin
• Vemurafenib
• Zileuton

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.

• Adinazolam
• Alprazolam
• Aminoglutethimide
• Amiodarone
• Azithromycin
• Brotizolam
• Cannabis
• Carbamazepine
• Chlordiazepoxide
• Clobazam
• Clonazepam
• Clorazepate
• Diazepam
• Disulfiram
• Estazolam
• Febuxostat
• Flunitrazepam
• Flurazepam
• Halazepam
• Interferon Alfa-2a
• Ipriflavone
• Isoproterenol
• Ketazolam
• Lorazepam
• Lormetazepam
• Medazepam
• Methotrexate
• Midazolam
• Nilutamide
• Nitrazepam
• Oxazepam
• Pancuronium
• Pentoxifylline
• Phenobarbital
• Piperine
• Prazepam
• Propafenone
• Quazepam
• Rifampin
• Rifapentine
• Riluzole
• Ritonavir
• Secobarbital
• St John's Wort
• Tacrine
• Telithromycin
• Temazepam
• Ticlopidine
• Triazolam
• Viloxazine
• 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 is usually not recommended, 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.

• Tobacco

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:

• Congestive heart failure or
• Cor pulmonale (heart condition) or
• Fever of 102 degrees F or higher for 24 hours or more or
• Hypothyroidism (underactive thyroid) or
• Infection, severe (e.g., sepsis) or
• Kidney disease in infants younger than 3 months of age or
• Liver disease (e.g., cirrhosis, hepatitis) or
• Pulmonary edema (lung condition) or
• Shock (serious condition with very little blood flow in the body)—Use with caution. The effects may be increased because of slower removal of the medicine from the body.

• Heart rhythm problems (e.g., arrhythmia) or
• Seizures, or history of or
• Stomach ulcer—Use with caution. May make these conditions worse.

It is very important that your doctor check the progress of you or your child at regular visits, especially for the first few weeks after you begin using this medicine. Blood tests may be needed to check for unwanted effects.

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

• Have had a fever of 102 degrees F or higher for at least 24 hours or more.
• Have started or stopped smoking tobacco or marijuana in the last few weeks.
• Have started or stopped taking another medicine in the last few weeks.
• Have changed your diet in the last few weeks.

Stop using this medicine and check with your doctor right away if you or your child have the following symptoms while using this medicine: nausea or vomiting that continues, headaches, trouble with sleeping, seizures, or irregular heartbeats.

Do not stop or change the dose of this medicine without checking first with your doctor.

Before you have any medical tests, tell the medical doctor in charge that you or your child are using this medicine. The results of some tests may be affected by this medicine.

This medicine may add to the central nervous system (CNS) 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 using this medicine. If you have questions about this, check with your doctor.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines for appetite control, asthma, colds, cough, hay fever, or sinus problems, and herbal (e.g., St. John's wort) or vitamin supplements.

Applies to theophylline: oral capsule, oral capsule extended release, oral capsule extended release 12 hr, oral capsule extended release 24 hr, oral elixir, oral solution, oral syrup, oral tablet, oral tablet enteric coated, oral tablet extended release, oral tablet extended release 12 hr, oral tablet extended release 24 hr

Other dosage forms:

• intravenous solution

Along with its needed effects, theophylline 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 immediately if any of the following side effects occur while taking theophylline:

• Chest pain or discomfort
• dizziness
• fainting
• fast, slow, or irregular heartbeat
• increase in urine volume
• lightheadedness
• persistent vomiting
• pounding or rapid pulse
• seizures
• shakiness

Get emergency help immediately if any of the following symptoms of overdose occur while taking theophylline:

• Abdominal or stomach pain
• blurred vision
• confusion
• confusion about identity, place, and time
• dark-colored urine
• decrease in frequency of urination
• decreased urine
• diarrhea
• difficulty in passing urine (dribbling)
• dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
• dry mouth
• fast, pounding, or irregular heartbeat or pulse
• fever
• increased thirst
• irregular heartbeat
• loss of appetite
• mood changes
• muscle cramps or spasms
• muscle pain or stiffness
• nausea or vomiting
• nervousness
• numbness or tingling in the hands, feet, or lips
• pain or discomfort in the arms, jaw, back, or neck
• painful urination
• shakiness in the legs, arms, hands, or feet
• shortness of breath
• sweating
• unusual tiredness or weakness
• vomiting of blood or material that looks like coffee grounds

Some side effects of theophylline 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:

• Headache
• irritability
• restlessness
• sleeplessness
• trouble sleeping
• unable to sleep

Loading dose: 5 mg/kg loading dose (patient not receiving theophylline or aminophylline).

Maintenance dose:

Otherwise Healthy Nonsmoking Adult: 10 mg/kg/day. Do not exceed 900 mg/day.

Otherwise Healthy Adult Smoker: 16 mg/kg/day.

Patient with congestive heart failure or cor pulmonale: 5 mg/kg/day. Do not exceed 400 mg/day.

Loading dose:
If no theophylline has been administered in the previous 24 hours: 5 mg/kg loading dose to achieve a serum concentration of about 10 mcg/mL; loading doses should be given using a rapidly absorbed oral product not a sustained release product).

If theophylline has been administered in the previous 24 hours: 2.5 mg/kg theophylline may be given in emergencies when serum concentrations are not available. A modified loading dose (mg/kg) may be calculated (when the serum level is known) by: [Blood concentration desired - blood concentration measured] divided by 2 (for every 1 mg/kg theophylline given, the blood level will rise by approximately 2 mcg/mL).

Maintenance dose:

less than 42 days: 4 mg/kg/day orally.

42 days to 181 days: 10 mg/kg/day orally. Alternate dosing: [(0.2 x age in weeks) + 5] x kg = 24 hour oral dose in milligrams.

6 months less than 12 months: 12 to 18 mg/kg/day. Alternate dosing: [(0.2 x age in weeks) + 5] x kg = 24 hour oral dose in milligrams.

1 year to 8 years: 20 to 24 mg/kg/day.

9 years to 11 years: 16 mg/kg/day.

12 years to 15 years: 13 mg/kg/day.

16 years or older: 10 mg/kg/day. Do not exceed 900 mg/day.

Manufacturer recommendations:
Loading dose: 4.6 mg/kg/dose
Maintenance:
Premature neonates: Post natal age less than 24 days: 1 mg/kg/dose every 12 hours
Premature neonates: Post natal age 24 or more days: 1.5 mg/kg/dose every 12 hours
Full term infants: Total daily dose (mg) = [(0.2 x age in weeks) +5] x (weight in kg); divide dose into 3 equal amounts and administer at 8 hour intervals

Alternative dosing:
Loading dose: 5 to 6 mg/kg/dose
Maintenance: 2 to 6 mg/kg/day divided every 8 to 12 hours

Data not available

Liver dysfunction:
Loading dose: 5 mg/kg loading dose (patient not receiving theophylline or aminophylline).
Maintenance dose: 5 mg/kg/day. Do not exceed 400 mg/day.

Calculate doses based on lean body weight. Base dose adjustments on improved clinical response and improvement in pulmonary function with careful monitoring of serum levels. Therapeutic serum level range 10 to 20 mcg/mL.