I keep finding terms such as 'accociated with consumption of promethazine' or 'promethazine may patentially cause'. I suppose because a POTENTIAL risk is known, it ironically prevents from performing a human study into promethazine use. Because all human studies are legally required to be ethical. Think about that for a moment - it took legal action to make pharmacutical companies test in an ethical manner.
Anyone else old enough to remember the fallout caused by thalidomide? Or, more recently, the 'Super MAB' scandal in the UK. Or internationally Pfizer testing a novel antibiotic on Nigerian children (in the city of Kano to be exact)? Even before that experimental HIV medications were given free to people who took part in the trial. Pharmacutical companies all apply 'the rule of poverty'.