Another example of unnecessary research, yet again because the results of preceding studies had not been gathered together and analyzed, concerns the treatment of stroke with a drug called nimodipine (one of a group of drugs called calcium antagonists).
If it were possible to limit the amount of brain damage in patients who suffer a stroke, their chances of disability should be lessened. Beginning in the 1980s, nimodipine was tested for this purpose in stroke patients after some animal experiments had given encouraging results.
Although a clinical trial in stroke patients published in 1988 suggested a beneficial effect, the results of several more clinical trials of nimodipine and other calcium antagonist drugs proved conflicting.
When the accumulated evidence of clinical trials involving nearly 8,000 patients was reviewed, systematically, in 1999, no beneficial effect of the drugs was found.  Since the use of nimodipine was apparently based on sound scientific evidence, how had this come about?
In the light of the results of research in patients, the findings from the animal experiments were scrutinized properly for the first time. Only when the animal studies were reviewed systematically did it become clear that the design of the animal experiments was generally poor and the results were beset by biases and therefore unreliable.
In other words, there had been no convincing justification for carrying out trials in stroke patients in the first place.