Under normal circumstances, this can only be done empirically by monitoring serum theophylline concentration at intervals and adjusting dosage until a steady state is reached with the serum theophylline concentration within the 10 to 20μg/ml therapeutic range. Discontinuation of a concomitant drug that increases Theophylline clearance will result in accumulation of Theophylline to potentially toxic levels, unless the Theophylline dose is appropriately reduced. Discontinuation of a concomitant drug that inhibits Theophylline clearance will result in decreased serum Theophylline concentrations, unless the Theophylline dose is appropriately increased. Theophylline comes as a tablet, capsule, solution, and syrup to take by mouth. It usually is taken every 6, 8, 12, or 24 hours. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Theophylline and caffeine are medications used to ease breathing and stimulate respiration in people with asthma or COPD. Lab tests measure blood levels to help determine the right dose, maintain a therapeutic level, or detect levels that are too high (toxic). This video is part of our soon to come MedMaster Course to help nursing students demolish NCLEX and Nursing Pharmacology. Tired of professors who don't seem to care, confusing lectures, and taking. Therapeutic drug levels are lab tests to look for the presence and the amount of a drug in the blood. Theophylline requires certain blood levels to be achieved for it to have a therapeutic effect but also can cause adverse side effects when this level is exceeded. Doctors often describe this as a narrow therapeutic range. -Obtain serum theophylline concentrations every 24 hours when giving intravenously; adjust infusion rate based on serum theophylline levels. -Steady state is reached after 3 days of oral dosing in most patients, assuming no missed or extra doses and doses were taken at even intervals. Therefore, theophylline blood levels are monitored periodically during treatment to assure achievement of optimal and safe levels. The initial dose is 300-600 mg once daily or as a divided dose for 3 days. The maintenance dose is 400-600 mg daily. Answer: The doctor will look at improved symptoms, any signs of side effects, and a blood test to measure theophylline when regulating your theophylline dose. If your breathing is more difficult, or side effects increase, notify your doctor.