This section provides information on the proper use of a number of products that contain theophylline.  It may not be specific to Quibron-T/SR. Please read with care.
Take this medicine exactly as directed by your doctor. Do not take more of it and do not take it more often than your doctor ordered. This medicine works best if there is a constant amount in the blood. To keep the blood level constant, take this medicine at the same time each day and do not miss any doses.
After you or your child begin taking theophylline, it is very important that your doctor check the level of the medicine in the blood at regular intervals to decide if the dose needs to be changed. Keep all appointments for testing the blood level.
Take the extended-release capsule or tablet every morning at the same time each day. You may take your second dose 10 to 12 hours after the morning dose and before the evening meal, unless your doctor tells you otherwise.
Swallow the extended-release tablet whole. Do not break, crush, or chew it. You may take the extended-release tablet with or without food.
It is best to take the extended-release capsule one hour before a high-fat meal or without food.
Measure the oral liquid with a marked measuring spoon, oral syringe, or medicine cup. The average household teaspoon may not hold the right amount of liquid.
Dosing
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.
To treat symptoms of asthma, bronchitis, and emphysema:
For oral dosage form (elixir or tablets):
Adults, teenagers, and children above 1 year of age weighing more than 45 kilograms (kg)—At first, 300 milligrams (mg) per day, divided and given every 6 to 8 hours. Your doctor may adjust your dose as needed. However, the total dose is usually not more than 600 mg per day.
Older adults—The dose must be determined by your doctor. However, the total dose is usually not more than 400 milligrams per day, divided and given every 6 to 8 hours.
Children and teenagers 1 to 15 years of age weighing less than 45 kilograms (kg)—Dose is based on body weight and must be determined by your doctor. At first, the dose is 12 to 14 milligrams (mg) per kg of body weight per day, divided and given every 4 to 6 hours. Your doctor may adjust your dose as needed. However, the total dose is usually not more than 20 mg per kg of body weight per day or 600 mg per day.
Infants younger than 1 year of age—Dose is based on body weight and age and must be determined by your doctor.
For oral dosage form (extended-release capsules):
Adults, teenagers, and children 12 years of age and older weighing more than 45 kilograms (kg)—At first, 300 to 400 milligrams (mg) as a single dose, usually in the morning, or divided and given two times per day. Your doctor may adjust your dose as needed. However, the total dose is usually not more than 600 mg per day.
Older adults—The dose must be determined by your doctor. However, the total dose is usually not more than 400 milligrams per day as a single dose, usually in the morning, or divided and given two times per day.
Children and teenagers 12 to 15 years of age weighing less than 45 kilograms (kg)—Dose is based on body weight and must be determined by your doctor. At first, the dose is 12 to 14 milligrams (mg) per kg of body weight per day as a single dose, usually in the morning, or divided and given two times per day. Your doctor may adjust your dose as needed. However, the total dose is usually not more than 20 mg per kg of body weight per day or 600 mg per day.
Children younger than 12 years of age—Use and dose must be determined by your doctor.
For oral dosage form (extended-release tablets):
Adults, teenagers, and children 6 years of age and older weighing more than 45 kilograms (kg)—At first, 300 milligrams (mg) per day, divided and given every 12 hours. Your doctor may adjust your dose as needed. However, the total dose is usually not more than 600 mg per day.
Older adults—The dose must be determined by your doctor. However, the total dose is usually not more than 400 milligrams per day, divided and given every 12 hours.
Children and teenagers 6 to 15 years of age weighing less than 45 kilograms (kg)—Dose is based on body weight and must be determined by your doctor. At first, the dose is 12 to 14 milligrams (mg) per kg of body weight per day, divided and given every 12 hours. Your doctor may adjust your dose as needed. However, the total dose is usually not more than 20 mg per kg of body weight per day or 600 mg per day.
Children younger than 6 years of age—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.
Storage
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.
Ask your healthcare professional how you should dispose of any medicine you do not use.
 Detailed Quibron-T/SR dosage information
