Isobel94.. Taking more insulin after treating a hypo is dangrous. The thing is as well with us diabetics that everyone is different. The OP HAS to be able to correct from a high to bring bg levels down to normal target range by the end of 5 hours. Any earlier than 5 hours depending what the cause of hyper is and what activity they are then doing could well ram straight into hypo, and a very bad one.
My advie is to establish, what level of quick acting will bring OP down to target at end of 5 hours.
The other thing is that all type 1's should know is how much their bodies need to bring themselves back to normal range and to be able to sustain it without bounding back up into hyper again. For example, last night, my level was 4.1 before I went to bed, I had 7 dolly mixtures and at 3am this morning I was 5.2. I get up early, so even at 5am this has maintained itself.
It would be so dangerous, if for example somebody took this info to give more insulin after treating a hypo.. When they were driving any sort of machinery or exercising....or at anytime to be honest.... As that person does not know how low they would actually be sinking to pre hypo stopper.....
In brief a t1 should have correct dosage of insulin to combat a hyper based on their correction factor... Yours may well be 1 unit to 4bgs, mine is different according to day or night and whether I am ill or working. The same for hypo's with me... 7 dolly mixtures good at night but during the dsy I would also have a shortbread to sustain my normal levels when they came back up. Dvla are exact on waiting 45 mins if you have a hypo... So why would you wish to give another jab at 20 mins when it is so strongly advised to wait at least 45 mins before driving for example.