Main Difference – Opioid vs Opiate
Opioid and opiate are two types of narcotic drugs used to relieve acute and chronic severe pain. Both drugs bind to opioid receptors. Opiates are a type of opioids. The main difference between opioid and opiate is that opioid refers to any drug that acts on opioid receptors in the brain whereas opiate refers to a subset of opioid derived from poppy. Opioids can be either synthetic or semi-synthetic drugs while opiates are natural, synthetic or semi-synthetic. Methadone, Demerol, Oxycodone, Fentanyl, Percodan, and Percocet are examples of opioids while opium, morphine, codeine, and heroin are examples of opiates.
Key Areas Covered
1. What is an Opioid
– Definition, Facts, Mechanism of Action
2. What is an Opiate
– Definition, Facts, Mechanism of Action
3. What are the Similarities Between Opioid and Opiate
– Outline of Common Features
4. What is the Difference Between Opioid and Opiate
– Comparison of Key Differences
Key Terms: Drug Addiction, Opiate, Opioid, Opioid Receptors, Opium Poppy, Pain Relievers
What is an Opioid
Opioid refers to a compound resembling opium with physiological effects or addictive properties. Fentanyl, Oxycodone, Hydrocodone, and Demerol are some examples of opioids. Opioids are safe for short time usage as prescribed by a doctor. The long-term use of them lead to drug addiction, produce euphoria, lead to overdose incidents or death. Opioid overdose can be reversed with naloxone. The structure of Demerol is shown in figure 1.
Opioids serve as agonists for opioid receptors in the brain and the body. The three types of opioid receptors are m, d, and k. There are another three types of naturally-occurring opioids in the body: b endorphin, enkephalin, and dynorphin. They are produced by the central nervous system and the digestive system. Each of these opioid acts upon a unique opioid receptor. The b endorphin binds to the m receptor. The enkephalin binds to the d receptor while dynorphin binds to the k receptor. Morphine acts as an agonist to the m receptor and the antagonist of the m receptor is naloxone.
Opioid receptors are coupled with G-proteins that generate inhibitory actions. Ideally, opioids act on both presynaptic and postsynaptic membranes. In the presynaptic membrane, they inhibit the release of neurotransmitters. As pain is a result of increased activity in the primary sensory neurons, the inhibitory effect on the signal transmission may relieve pain.
What is an Opiate
An opiate refers to a compound derived from or related to opium poppy plant. Morphine, opium, codeine, and the illegal drug heroin are examples of opiates. Opiates depress the activity of the central nervous system. Opium poppy plant is shown in figure 2.
All opiates can be divided into three groups. The active compounds of some of the opiates are naturally occurring such as morphine. Some opiates consist of partially synthetic, morphine derivatives such as oxymorphone and heroine. Others are synthetic compounds such as codeine. The structure of morphine is shown in figure 3.
Heroin is the prodrug of morphine and is metabolized into morphine in the liver. It is one of the most dangerous drugs in the world as it causes countless death each year.
Similarities Between Opioid and Opiate
- Both opioid and opiate are two types of narcotic drugs that relieve pain.
- Both opioid and opiate act upon the opioid receptors in the brain.
- Both opioid and opiate can be synthetic drugs.
- The usage of opioid and opiate for a long period of time leads to drug addiction.
Difference Between Opioid and Opiate
Opioid: Opioid is a compound resembling opium, having physiological effects or addictive properties.
Opiate: Opiate is a compound derived from or related to opium poppy plant.
Opioid: Opioids are narcotic drugs that act on the opioid receptors in the brain.
Opiate: Opiates are a subset of opioids derived from plant materials.
Opioid: The active ingredients of opioid are chemically synthesized.
Opiate: Opiates are alkaloids derived from the opium poppy.
Opioid: Opioids can be either a synthetic or semi-synthetic drug.
Opiate: Opiates are natural, synthetic or semi-synthetic.
Opioid: Methadone, Demerol, Oxycodone, Fentanyl, Percodan, and Percocet are examples of opioids.
Opiate: Opium, morphine, codeine, and heroine are examples of opiates.
Opioid and opiate are two types of narcotic drugs that act on the opioid receptors in the brain. Opioids mainly consist of synthetic compounds as their active ingredients. However, opiates are derived from natural ingredients. The main difference between opioid and opiate is the origination of the active compounds of each type of drug.
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2. Chahl, Loris A. “Opioids – mechanisms of action | Australian Prescriber.” NPS MedicineWise, 1 July 1996,
3. “What Drugs Are Opiates?” Casa Palmera, 17 Nov. 2016, .
1. “Pethidine-2D-skeletal” By User:Benjah-bmm27 – Own work (Public Domain) via
2. “Papaversomniferum” By Marknesbitt assumed (based on copyright claims). Own work assumed (Public Domain) via
3. “Morphine-2D-skeletal” By Benjah-bmm27 – Own work (Public Domain) via