What are the effects of abusing opiates?

I heard my sister and her best friend talking something about trying opiates. I know that it is a drug but I don't know much about its properties or effects. I confronted my sister about it but she just told me to back-off. I think I'll convince her not to take drugs if only I know the negative effects of opiates. I'm sure she'll be scared to death if I tell her. Please help me. I need some answers asap.

Made from opium, opiates makes the user to feel intense one moment and drowsy the next. It affects the function of the brain by decrease anxiety, inducing sleep and promoting sedation. Some types of opiates are heroin, codeine and morphine. Opiates causes the user to loose motivation over work or studies, feel indifferent towards other things and deny any sort of problems. It also has a terrible effect on a person's health. Tell your sister that opiates dependency may lead to suicidal tendencies. I'm sure, she'll listen to you.

Hon, God forbid that she should get hooked on them because to come off of them it is a very bad withdrawal. Take it from me, I was on Vicodin for a very long time and to get off of them it was absolute torture. At the end when I first came off of them I was sick to my stomach, had a terrible headache, had chills and profuse sweating. Not a pretty sight. I had to take 6 Vicodin to assuage my pain and had terrible headaches because of overdose of my pills, my head buzzed like when you take too many aspirin. I felt sick all of the time.

Again, God-forbid she ever needs them for pain, they won't work for her. Having a tooth pulled like a wisdom she will need to take pain meds that work or she will be in great pain.

she'd have to be out of her mind to do that. They are very addictive and can cause liver problems. If she ever actually needs to have a strong pain killer for a legitimate reason, nothing will work as her body will have become resistant. To buy them you'd have to have tons of money.......please just tell her not to wreck her life.

Addiction, physical dependence, liver failure. respiratory failure and death if overdosed... Too much opiate causes a person to stop breathing and shorty after that naturally their hearts will stop beating... Opiate overdose is all too common

I'm glad that you are concerned for your sister. But, you can't convince someone not to take illegal substances, if they don't want to stop.
For starters, opiates, methamphetamine, "crystal meth", is very bad for you! I don't know all of the side effects, but I do know that you can take that stuff now, and still have serious hallucinations many years later, even if you have gotten clean!
These drugs can make you feel like you can fly, for instance. Some people have thought that, and have jumped off of a tall structure (building, for example), thinking that they can fly. That is fatal, obviously.
These drugs eat brain cells, and if taken in larger and larger quantities, are highly addictive. They have done studies on mice, and offered them cocaine, food, and sex. They choose the cocaine.
Talk to somebody about this. If your sister and her friend are thinking about getting high, that affects you, and everyone around you.
M.