
Depending on the sources it's either called, alternative, holistic or homeopathic, but one thing is clear: the articles state that the people say they took nothing (at least knowingly) that could cause them to become poisoned and so ill they are falling over. As you can see above ambulances and even one helicopter had to be sent out.
From the article:
Authorities say emergency workers called to a conference center in northern Germany found some 30 practioners staggering and suffering from cramps, apparently as a result of amphetamine poisoning.In the wake of my unintentional series on holistic doctors dying, I had several people send this to me the last few days. I admit I scanned it, but only today saw the severity of the story. Again, they say they didn't knowingly ingest anything that would cause them to become deathly ill. (poisoned)
The local government said 15 ambulances and a helicopter were sent to the scene Friday in the small town of Handeloh, south of Hamburg, the dpa news agency reported.
Fire service spokesman Matthias Koehlbrandt told broadcaster NDR the group was aged between 25 and 55. NDR reported they were alternative and homeopathic practitioners, and that they were taken to the hospital.
Authorities said their preliminary finding was that the group was poisoned with amphetamines, but Koehlbrandt said they didn't knowingly take the substance.
We hope all the practitioners will have a full recovery and will update you on the situation as soon as we have more information. This is Erin Elizabeth in the state of Florida on Sept 7th , 2015



I think this is the original article: [Link]
I don't know if there is any other information there, but I don't trust media. In the German article they mention that practitioners likely did a 'test' on themselves and it went wrong, they got an overdose. In the report they mention normal doctors too, but not in the article. In the German article nothing is known yet, and nobody said they didn't take anything.
The German article makes the whole story as if the practitioners were voluntarily on drugs, in order to discredit them.