Once the user is addicted, withdrawal is terribly difficult. Heroin overdose can lead to coma or death. Amphetamines are swallowed in pill or capsule form, or injected. Their general effect is exaggerated activity, irritability, and nervousness. An excessive amount may even produce symptoms of paranoia.
Hallucinations are common.
Some abusers can remain awake continuously for a long as six days . . . The danger of suicide exists. Overdoses can result in death. Inhalants Substances that are abused by sniffing fall under the category of inhalants. These include gasoline, airplane glue, paint thinner, dry cleaner solutions, and others.