During Detective Lt. Jonathon Simpson's first seven years with the Madison Police Department, he only saw one case involving heroin. But in his eighth year, heroin has burst onto the scene and has become the newest drug problem facing him and his fellow officers.

So far this year, Simpson has investigated 10 heroin cases. There are at least six pending cases in Jefferson Circuit Court dealing with possession of heroin.

The Substance Abuse and Mental Health Services Administration has determined the number of teens who are dying from heroin nationwide has been rapidly increasing. In 1999, 198 people aged 15 to 24 died of a heroin overdose. That number increased to 510 by 2009.

In its purest form, heroin is a fine white powder. It can be gray, brown, yellow or black depending on what other substances are cut with the drug.

According to the Drug Enforcement Administration, physical symptoms of heroin use include drowsiness, respiratory depression, constricted pupils, nausea, warm flushing of the skin and heavy extremities.

An overdose of heroin can be accompanied by slow and shallow breathing, blue lips and fingernails, clammy skin or convulsions, and could possibly result in the user becoming comatose or dying.

Simpson said a majority of the heroin that shows up in Madison comes from Ohio, specifically from Cincinnati or Dayton. Police arrested one man from southwestern Ohio because they suspected he came to Madison to sell heroin.

Heroin is considered to be a step on a cycle of drug use that officers watch for. The first step in the cycle is hydrocodone, which is followed by oxymorphone, Opana and heroin.

Users will move on to the next stage of the cycle when the high they attain from the previous drug is no longer enough to satisfy their addiction, Detective Lt. Tyson Eblen said.

The step to heroin also seemed necessary because of changes that were made to Opana and OxyContin pills. Pharmaceutical companies added a gel to pills that made users unable to grind or chop them up.

The pills were typically broken down to avoid the time-release technology that is used in pills. By grinding up the pills and injecting them, users could get all the effects of the drug at once. Time-release allows the drug to be administered in set doses over time.

The drop-off in Opana and OxyContin began around January, Simpson said, and heroin showed up a short time later.

For the cycle of drug usage to begin again, users will typically be prescribed hydrocodone to help them with heroin addiction, Eblen said. Continued use of the hydrocodone will typically lead to the same cycle of drug use.

And police already have their eye on the next big drug that could hit the city. Zohydro is still subject to approval by the Food and Drug Administration, but is predicted to be available as a treatment for chronic pain in 2013.

What's different about this pill, according to Eblen, is that it does not have acetaminophen, which can cause liver problems with excessive use. Now, users can take Zohydro without having to worry about liver problems.

"My guess is it's going to become a popular pain pill for these people and heroin will decline," Simpson said.

But for now, authorities are battling heroin use and don't expect the problem to go away any time soon.