I also have an 8 yr old dtr-SWCAH.  The blood draws are done at the ped endo’s office every 3-4 months.  We are always there in the afternoon, but I’ve never been told to bring her in  any specific time just for blood draws.  Also, we do not give her meds at such strict times.  Usually it’s when she wakes up, midday and at bedtime.  The times may vary but the time between each dose is about the same.  I have’nt seen a negative effect yet.  I hope we are not too relaxed about it.  We are not relaxed about the IM dose however-I use the motto, when in doubt-inject.