Speed drug. Powder of the drug Speed (Methamphet- amine) with a razor blade used to cut it into lines for snorting. Amphetamines of which Speed is a type are a group of drugs which stimulate the central nervous system and suppress appetite. Once used as slimming and anti-depressant drugs, amphetamines have been widely abused since the 1960s, being snorted, injected, sometimes smoked. Amphetamines heighten alertness, elevate mood and decrease fatigue. Side effects include high blood pressure, hyperactivity and irritable moods. Prolonged use can lead to addiction and psychotic mental states. Users rapidly develop tolerance to the drug's effects.