A 1/4 of a gram really isn't anything to worry about. Most people tend to use between 1-2grams at any given time.
Short term - the user will lose weight, become very irriatable, get tooth ache , serious bags under the eyes from lack of sleep, but they will feel great whilst on speed.
Long term - Teeth will start to rot, normal speed with be replaced with base-speed (more expensive pure form) or more than likely cocaine, user will look gaunt and pale, serious loss of weight and paranoia.