How long after my theophylline dose should my blood be drawn?
If the sustained release theophylline is given twice a day, then a good time to measure a level is 4 hours after the morning dose. If the sustained release theophylline is given only once a day, then the blood should be drawn 8-12 hours after the dose. For example, first thing in the morning after the evening dose. These are the times when the theophylline level is highest in the blood. Your doctor may want to know your lowest blood level of the day. This is often drawn before the dose is due. Since every person is unique, the above times are general guidelines. Your doctor may have a special reason to suspect that your theophylline requirement is different and may want your blood levels checked at other times.
