Sedatives (or ‘downers’) are a category of drugs that slow down normal brain function. There are two basic groups of sedatives;
– Opioids; Similar to established recreational opioids, but with the potential for much longer durations of action.
– Benzodiazepines; Sedative, anxiolytic, hypnotic, and anticonvulsant properties–some with long duration of action.
These NPS act like benzodiazepines, opium, heroine.
Examples are MT-45, AH-7921 and novel fentanyls (opioids) or diclazepam and flubromazepam (benzodiazepies).

Short term risks include overdose, confusional states en seizures (after withdrawal)
Long term risks include addiction and impaired cognition.
The risk are heightened particularly when mixed with alcohol or other sedatives.

Sedatives are snorted, smoked, injected or swallowed.

For more (fairly technical) information on the different NPS’s, you can visit these pages of the UN and Tripsit .

Source: 1, 2, 3