Opiates are medications that activate specific parts of the brain called opioid receptors. Opiates come in many forms, including heroin and narcotic pain relievers. These compounds work to activate parts of the brain involved in euphoria and pain relief. Long-term opiate use can result in opiate addiction, and once this happens, stopping opiate use leads to withdrawal symptoms which can vary in intensity depending on the type of opiate being used.
Early Symptoms
Withdrawal symptoms can start within 12 hours of the last use of opiates. Some of these early symptoms include muscle aches, anxiety and increased tearing (hyperlacrimation) of the eyes. Some patients also become agitated and experience increased sweating (hyperhidrosis), increased yawning and problems falling asleep/staying asleep. Other patients experience an extreme longing for opiates. These symptoms may be very uncomfortable but they are not life-threatening. In some cases, these symptoms can be relieved by using long-acting opioid agonists which help block withdrawal effects but provide less of a narcotic "high."
Late Symptoms
As patients progress through the early symptoms of opiate withdrawal, their symptoms may change both in type and severity. Some of the later symptoms of opiate withdrawal include nausea and vomiting, as well as extreme diarrhea. Other symptoms include goosebumps and problems with abdominal cramping. In some cases, according to the University of Michigan, patients develop dilated pupils as well as muscle tremors and shakes. Patients may also experience an elevated heart rate and rapid breathing, as well as spontaneous orgasm. These symptoms are typically the most extreme of the withdrawal symptoms.
Rebound Symptoms
One of the effects of opiates is that they suppress part of the autonomic (unconscious) nervous system. In particular, they block the actions of the "sympathetic" nervous system, which is responsible for alertness and muscle action. As a result, sometimes patients going through opiate withdrawal experience abnormal activation of this part of their nervous system, leading to abnormal muscle contractions (also known as "restless leg syndrome") and abnormal itching (as the blood vessels become activated). It is this heightened nervous activity that is also responsible for the muscle shakes and insomnia.
