Opioid drugs are analgesics that can help relieve moderate to severe pain. They are commonly prescribed to treat surgical pain.
But in recent years, people have misused these drugs leading to addiction, overdose and death. Morphine is one of the potent opioid painkillers used in medicine. Its side effects include breathing problems, chest pain, muscle stiffness, constipation, nausea and dizziness.
Opioid painkillers are the leading cause of deaths due to drug abuse. Opioid addiction refers to the compulsive use of drugs such as morphine, heroin obtained from the opium poppy alkaloids.
Opioid drugs connect to certain opioid receptors present in the central nervous system. There are 3 major classes of opioid receptors; mu receptors responsible for effects such as analgesia, respiratory depression. Kappa receptors which mediate effects like miosis, respiratory suppression and sedation. Sigma receptors mediate hallucinations and psychosis and delta receptors mediate euphoria, analgesia, and seizures.
These drugs when taken in higher doses can cause severe respiratory depression and death. The most common symptoms are unconsciousness, respiratory suppression and pinpoint pupils.
The maximum number of deaths due to drug overdoses occurred in the year 2014. About 207,400 drug-related deaths were registered worldwide. In the United States, 47,055 deaths occurred in 2014. Among this, 28,000 people died due to opioid overdose in the US. Increased availability and cheaper prices are fueling opioid overdose epidemic in the US.
The only available drug to treat opioid overdose is Naloxone, which can antagonize all the four opioid receptors.
But researchers from the Stanford University have identified a new opioid that has the pain-relieving properties of the drug devoid of its addictive side effects.
Scientists cracked a similar opioid compound that will fit the opioid receptor in the brain by trying out various configurations. They named this new compound as PZM21, which was selected after analyzing 3 million compounds and narrowing down to 2,500 compounds. They used computer-based screening methods to create the compound.
PZM21 was tested in mice where the compound reduced the pain like that of morphine. But it did not impose any breathing difficulties in mice which is a side effect of morphine. The compound is less lethal as it does not trigger addictive sensation like other opioids.
Although, the research led by Dr. Aashish Manglik has made us get closer to the opioid reversal drug, further testing is needed to develop the optimal drug. Several scientists have hailed the research as promising.