Opiates and opioids have given rise to the fastest growing drug epidemic of the 21st century. According to the National Institute on Drug Abuse, an estimated 2.1 million Americans struggled with prescription pain pill abuse in 2012 with an additional 467,000 addicted to heroin. These numbers continue to rise with each passing year.

While often used interchangeably, the terms opiates and opioids actually refer to two different categories of drugs. Not surprisingly, opiates and opioids produce the same effects on the body for the most part, though some differences do exist depending on any one drug’s overall purpose.

Considering the strong similarities these drugs share, what you should know about opiates and opioids has more to do with how these drugs interact with the body and their effects over time.

Opiates and Opioids – What’s the Difference?

Both opiate and opioid drugs derive from a single source: the opium poppy plant. While not all come directly from this plant, the ones that don’t have chemical make-ups capable of producing similar effects.

Most all opiates and opioids act on the body’s central nervous system, slowing down chemical activities throughout the brain and body. These interactions produce pain-relieving effects that make for effective analgesic agents.

More than anything else, opiates and opioids differ in terms of where they come from rather than the effects they produce. Opiates exist as naturally occurring derivatives of the opium poppy plant. Opioids exist as synthetically made compounds formulated to produce the same types of effects as natural opiates.

The Endogenous Opioid System

The human body houses its very own pain relieving mechanisms that combine to form the endogenous opioid system. Within this system, certain key protein molecules known as opioid peptides modulate nerve signal transmission processes throughout the body on an as-needed basis. According to Virginia Commonwealth University, nerve cells within the central nervous system and various glands, such as the pituitary and adrenal glands manufacture these peptide materials.

The endogenous opioid system also houses opioid receptor sites specifically designed to bind with these peptide molecules. Opioid peptides produce the same pain-relieving effects as opiates and opioids. Likewise, the body responds to opiate and opioid drugs in the same way it responds to opioid peptide materials.

Technically speaking, the term opioid encompasses both opiates and opioid drugs as all derive from the opium poppy plant and interact with the body’s opioid system in the same ways.

Types of Opiates

Considering the wide range of opiates and opioids in existence, these drugs can be separated into different categories or types. Opiates encompass the natural poppy seed plant derivatives, including:

• Morphine
• Codeine
• Thebaine
• Oripavine
• Opium
• Papaverine

The two remaining categories of opioids include synthetic and semi-synthetic. According to the Centers of Medicare and Medicaid Services, some of the more commonly known synthetic opioids include:

• Meperidine
• Pentazocine
• Fentanyl
• Methadone
• Tramadol
• Propoxyphene

Semi-synthetic opioids contain both natural opiate compounds and synthetic non-opioid agents, such as aspirin, ibuprofen and acetaminophen. Semi-synthetic varieties include:

• Hydrocodone
• Heroine
• Oxycodone
• Hydromorphone
• Dihydrocodeine
• Hydrocodone

Types of Opiate and Opioid Effects

Opiates and opioids can produce a range of effects depending on any one drug’s formulation and intended purpose. While all types act on the body’s opioid system, different drugs interact with this system in different ways.

In general, opiate and opioid drug effects fall in one of the three categories:

• Full agonists
• Antagonists
• Partial agonists

Full Agonists

According to the U. S. National Library of Medicine, full agonist drugs activate opioid receptor sites in the body. Once activated, these sites release endorphins, the body’s own “feel-good” chemicals.

This release of endorphins sets off a chain of chemical reactions, causing essential neurotransmitter chemicals, such as serotonin, dopamine and norepinephrine to flow through the brain and central nervous system. These chemicals regulate a number of vital bodily processes, including:

• Respiration
• Circulation
• Cognition
• The limbic system, the emotion-based centers of the brain
• Heart function
• Body temperature regulation

With a full agonist, an increase in dosage amount increases or intensifies the drug’s effects. Not surprisingly, drugs belonging to this category carry the highest potential for abuse and addiction potential.

Full agonist opiates and opioids include:

• Heroin
• Morphine
• Hydromorphone
• Oxycodone

Antagonists

Antagonist opiates and opioids bind to the same cell receptor sites as full agonists only these drugs don’t activate receptor sites nor do they trigger neurotransmitter secretions. By binding to these sites, antagonists block other types of opiate/opioid drugs from activating them.

This mechanism of action makes for an effective addiction treatment medication as addicts who attempt to use addictive opioids when on an antagonist drug won’t experience a “high.” Commonly used antagonist drugs include:

• Naltrexone
• Naloxone
• Ultram
• Stadol

Partial Agonists

Partial agonist opiates and opioids produce both agonist and antagonist effects. Unlike full agonist drugs, partial agonists have a built-in ceiling effect. This means, once a certain dosage level is reached a partial agonist will stop activating cell receptor sites.

At high dosage levels, partial agonists produce antagonist effects, acting as blocking agents that prevent any further activation of cell site receptors. Some partial agonists may still partially activate receptor sites, but at nowhere near the intensity of a full agonist agent.

Partial agonists also offer valuable benefits as addiction treatment medications because of their ability to relieve uncomfortable withdrawal effects while reducing the potential for relapse. Commonly used partial agonist drugs include:

• Suboxone
• Subutex
• Buprenorphine

Opiates and Opioids – Long-Term Effects

When used as prescribed, agonist-type opiates and opioids work well at relieving most every type of pain symptom. When abused or used for prolonged periods of time, these drugs carry an incredibly high potential for addiction.

In effect, opiates and opioids alter essential chemical processes in the body, and over time can change how the brain and body work. In the process, the body becomes physically dependent on the drug, relying on its effects to function normally. With ongoing abuse, the mind develops a psychological dependency to the point where users come to believe they need the drug’s effects to cope with everyday living.

Ideally, opiates and opioids should only be used on a short-term basis not to exceed three months at a time. Otherwise, the adverse effects of these drugs start to take over.