Presentation[1][2][4]
Abusers typically self-administer the drug in 'runs' of several days, with intervening periods of abstinence.[5] Whilst on a 'run', an individual may stay awake continuously for up to 10 days with little food or drink. Prolonged sleep and mild dysphoria occur as the drug wears off.
Immediate subjective effects include:
Euphoria.
Increased alertness.
Increased energy.
Increased libido and enhanced sexual pleasure.
Decreased inhibition.
Decreased appetite.
Decreased need for sleep.
Peripheral actions arise due to the indirect sympathomimetic effects of the drug:
Tachycardia.
Hypertension.
Palpitations.
Tachypnoea.
Sweating and hyperthermia.
Dry mouth.
Decreased gastrointestinal (GI) motility.
Dilated pupils.
Tremor.
Central actions may account for some of the other typical behaviours and movement disorders seen such as:
Jaw clenching.
Repetitive jerking and choreoathetoid movements.
Compulsion with repetitive tasks ('punding').
Formication (sensation of flesh crawling with bugs with associated compulsive picking and infected sores).
Repetitive movements, hyperactivity, and difficulty focusing thought are sometimes referred to as 'tweaking'.[4]
http://www.patient.co.uk/doctor/Crystal-Methamfetamine-Drug-Abuse.htm
