Asthma UK community forum

theo levels - what are yours like

Hi all

My son takes slo phyllin (has done since April) and currently takes 250 twice a day. He had never had his blood levels checked until Monday after a funny turn. His levels were 14.9, apparently just right. He had this 8 hours after reduced dose (125mg). Was wondering what other peoples levels were. What do you get good control from and what levels make you have side effects.

Would his levels have dropped as he only had 1/2 usual dose that morning or would this not really have much effect.

Look forward to some replies


8 Replies

Hi , my son Sean is the same age as your son and has been taking slo-phyllin since may 06. His starting dose was 250mg bd, in dec the brompton checked his levels and was only 4, increased to 310mg bd tested 4 days later and levels 7.1, another increase to 375mg bd and levels still low at 7.9 so on 21st dec they increased to 375mg am and 500 mg pm and if no side effects by xmas eve increased to 500mg bd. We followed the instructions and Sean had a seizure on xmas day where he was unconsious and violently fitting and blue lighted to local. They tested theo levels but it was 8 hrs post last dose and they were 21 which is borderline toxic.Docs think that his levels would have been much higher three hrs previously so theo toxicity was prob the cause.As slophyllin is a slow release drug and the fit was 5 hrs post dose this also confirms fit was prob cos toxic. His dose was then decreased to 375mg bd again and we are seeing brompton on friday to discuss further.

I have been told that bloods should be taken 4-6 post last dose and blood tests should be done 3-4 days after any change in medication. The scare we had on xmas day has certsainly made me more aware of how serious some side effects can be. The dilemia we now have is on 375mg Seans levels are too low so prob not doing much good but 500mg could cause another fit which isnt a risk I am prepared to take again. His respiratory nurse at rbh is finding out info about toxicity for me from the medical info dept and pharmacy at rbh so if i find out anything of interest ill let u know.

I hope your son doesnt have any more funny turns.

Julie x


Apparently when theraputic has a broncodilator effect but even when sub theraputic it still works in like an anti inflammatory way, I have 400mgs uniphylin twice a day and levels never above 5 on oral, need lots high dose iv to get above 10.

Andrea xx


Somewhere in my boots despite elephant amounts orally . Just to clarify one thing there is thinking that you get an anti-inflamatory benefits at as low as 3 apparently, I know between 5-10 have been mentioned before but the last I heard was it can be as low as 3 hence why I still take it.



Seans resp nurse from rbh has been on phone today, she says that between 5 and 10 has an anti flammtory effect so looks like we all on same wave length :-)

Its a relief to hear that for me as it means we dont have to make a decision now whether to risk increase again as his levels are 7 on 375mg bd so that is good enough for me :-)


My levels range from 3 to 18 in an apparently random fashion! I had absorption studies at RBH which showed that I get good levels (>10) for the first 4 - 5 hours after I take it and then they drop off. I'm currently taking it every 8 hours which seems to help - if I took the same total dose but 12 hourly I'd likely run into toxicity problems in the first few hours after taking it.

From experience of being on IV and having daily levels done, I would say I feel very much better with levels of 16 and over - I presume that is when the bronchodilatory effect kicks in maximally for me personally. Unfortunately I can't achieve those sorts of levels consistently on the tablets!

When I am struggling with my breathing I think to myself that I would not mind being toxic if I could breath, but from my few experiences of toxicity (and I have never been badly toxic or fitted, thank goodness) it is too high a price to pay - the chest does feel good when toxic but the rest of you feels darned awful!

It's a strange and annoying drug.

Take care all

Em H



I was on theophilline for around 4 years but have had it stopped. I started on 250mg but didnt help so within a few months was on 375mg, but i kept reading levels as low as 3- prompting questions was i actually taking it (I was). I was then put on 500mg but i started becoming quite sick when i had bad asthma so when had doses checked was low again so docs still thought i wasnt taking it. We now realise this was due to sickness, i was probably often toxic I then had a bronch and they found my levels were 23 which is slightly toxic as was being so sick.

Then last July I got to the point where i couldn't keep anything down for 6 days but the last 48 hours i couldnt sip water. So had test (this was before i took my dose as i have always been told theophilline should be a fasting dose) before my test i was 129/140 (it is meant to be 70-80 for my age) i was admitted for detoxification.

Having said all this my asthma has never been the same since i came of it!

Good luck

May x


when they did my theo level at the beginning of s admission it was a pile of pants at 0.8 !!! the docs reckon i may have had a dodgy batch from the pharmacy. quite scary.


My levels are all over the place for no apparent reason go from 2 to 28 (very toxic collapsed)

My first warning of being too high is a tremor not a headache/vomiting but the dr has pointed out that because i play the violin and piano i may be more sensitive to noticing that (i usually point out when i've got the tremor can't even hold the violin!!!)

Interestingly my best ever peak flow of 570 was when i was totally toxic so my naughty lungs can cooperate they just choose not to!


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