What is methadone dependency?

As an opiate, regular use of methadone causes physical dependency - if you've been using it regularly (prescribed or not) once you stop you will experience a withdrawal. The physical changes due to the drug are similar to other opiates (like heroin); suppressed cough reflex, contracted pupils, drowsiness and constipation. Some methadone users feel sick when they first use the drug. If you are a woman using methadone you may not have regular periods - but you are still able to conceive. Methadone is a long-acting opioid; it has an effect for up to 36 hours (if you are using methadone you will not withdraw for this period) and can remain in your body for several days.