Often known as speed, whizz, billy or uppers. See also Crystal Meth.

Amphetamines are stimulants normally taken by mouth or snorted up the nose. Amphetamines usually come in powder form, although tablets may also be encountered. It is sold in `wraps' of one gram, and the price has remained fairly stable at around £10 a gram for many years. Speed is usually cut with other forms of powder such as ascorbic acid, icing sugar, cornflour and talc.

Amphetamines can also be injected. It is important to be aware that HIV can be transmitted through sharing needles and syringes used to inject speed in just the same way as with heroin. The frequency of injecting speed seems to vary widely from one part of the country to another.

Most amphetamines come in the form of amphetamine sulphate powder. Amphetamines are treated as Class B drugs under the Misuse of Drugs Acts unless they are prepared for injection, in which case they are classified as Class A drugs.

Amphetamines cause the heartbeat to speed up, appetite to diminish, the pupils to widen and mood to improve. Users experience a rush of confidence and energy which can last for three to four hours before they begin to `come down'. Feelings of anxiety and restlessness begin to take over at this point. Grinding of the teeth is a common side–effect of amphetamine use. Repeated use of amphetamines leads to tolerance and can lead to more exaggerated feelings of anxiety, paranoia and panic. Long-term heavy use may result in mental disturbances which become more pronounced with time.

Amphetamines postpone the need for food and rest but don't eliminate these needs altogether. This means that regular users can begin to suffer from poor diet and weight loss. In turn this affects resistance to infection, so HIV-positive users need to be especially wary of over–taxing the body with repeated amphetamine use.

The effect of speed use on diet and sleep means that women who are regular users of the drug may experience irregular periods. Speed also affects unborn children, leading to low birth weight, although it is not thought to lead to birth defects.

Crystal meth – see below – is a form of amphetamine which gives a longer-lasting and more intense ‘high’. Although there is little evidence that ‘regular’ speed users have faster progression to AIDSA, crystal meth has been found to increase the rate of HIV replication and accelerate HIV- related dementia.