It's a bit of a long-shot, but I think you may have been prescribed a drug called Melleril (Thioridazine). The reason I'm not positive about this is that Melleril was licenced for use as an anti-psychotic drug and was normally prescribed in divided doses throughout the day for schizophrenia, other psychosis, severe agitation and dangerously impulsive behaviour.
Melleril was sometimes prescribed for insomnia and "sleep disturbances" and like other hypnotics, it was then normally prescribed as a single dose at bedtime. All the same, it was never a particularly popular hypnotic with the medical profession as it was such a powerful mind-altering drug.
Melleril was discontinued in 2005 as it was found to cause some peculiarities in ECG waveforms in patients and also because newer drugs were found to be more efficient and safer.