Pharmacology
DrugBankDescription
Opium is the first substance of the diverse group of the opiates. It has been known for a long time, and the first evidence of a poppy culture dates from 5 thousand years by the Sumerians. During the years, opium was used as a sedative and hypnotic, but it was determined to be addictive. Opium is extracted from _Papaver somniferum_, which is more known as poppies. This plant is an integrant of the Papaveraceae family, and it is characterized by solitary leaves and capsulated fruits. Therefore, opium is a sticky brown resin obtained by collecting and drying the latex that exudes from the poppy pods. Once extracted, opium contains two main groups of alkaloids; the psychoactive constituents which are in the category of phenanthrenes and alkaloids that have no central nervous system effect in the category of isoquinolines. Morphine is the most prevalent and principal alkaloid in opium, and it is responsible for most of the harmful effects of opium. Opium has gradually been superseded by a variety of synthetic opioids and general anesthetics. Some of the isolated derivatives of opium are morphine, noscapine, strychnine, veratrine, colchicine, codeine, and quinine. Opium is a prohibited drug of abuse in most countries, but the illegal production of this drug and its derivatives keeps being registered. There is some legal production of opium in different countries for the obtention of alkaloids by extraction.
Mechanism of Action
Opium produces its effects by activating specific G protein-coupled receptors in the brain, spinal cord, and peripheral nervous system. There are three major classes of opioid receptors being δ-opioid, κ-opioid and μ-opioid. Opium will generate an agonist activity which will later open the potassium channels and prevent the opening of voltage-gated calcium channels. This activity causes a reduction in neuronal excitability and inhibits the release of pain neurotransmitters. The addictive character of opium is related to the binding to the μ-opioid receptors, which will activate dopaminergic neurons in the ventral tegmental area of the midbrain and thus, enhance the dopamine release in the nucleus accumbens. This mechanism involves the reward activity of the mesolimbic dopaminergic pathway.
Pharmacodynamics
Opioids can reduce the intensity and unpleasant feeling of pain. The unspecific effect of opium to the different opioid receptors produce the generation of various effects such as sedation, euphoria, dysphoria, respiratory depression, constipation, pruritus, nausea, and vomiting. It is reported that the secondary effects tend to be diminished as long-term use tolerance is developed. Some reports have also shown an opioid-driven impairment of the hypothalamic function that can result in a loss of libido, impotence, and infertility. Patients have reported a sensation of stress relief even in presence of pain as well as the presence of sedation, hypoventilation, cough inhibition, prolonged apnea, myosis and respiratory obstruction. In the cardiovascular system, there are reports of peripheral vasodilatation, including cutaneous causing flushing of the face, neck, and thorax, impaired sympathetic reflexes and postural hypotension. In the gastrointestinal and urogenital system, the increase in smooth muscle tone has been shown to produce reduced peristalsis, delayed gastric emptying and urinary retention.
Metabolism
Opium contains 50 different alkaloid opiates. The most common metabolism of opiates is to be ultimately converted to morphine which is further converted to morphine-3,6-diglucuronide. Opioids are metabolized vastly by the enzyme CYP 2D6 and any mutation in this kind of enzyme or coadministration with drugs that interfere with this enzyme may generate a change in the metabolism speed. For years, because of this metabolism pathway, it was very hard to differentiate between illicit heroin users and involuntary exposure to poppy seeds. The original tests for this differentiations were based in the presence of morphine in urine without evidence of 6-monoacetylmorphine. Now it is known the presence of a glucuronide metabolite only in the consumption of heroin called ATM4G and this allows a clear differentiation of the consumption of illegal heroin and poppy seed ingestion.
Absorption
After oral administration, opium bioavailability is poor. In the form of opioid tincture, the Cmax and AUC of opium are between 16-24 mg/ml and 3237-6727 ng/ml.h, respectively.
Toxicity
Some toxicity concerns from the consumption of opium are the generation of addiction, physical dependence and tolerance to the effect. Studies regarding the opioid tolerance in the treatment of chronic pain have not been systematically investigated. There are also concerns about the opioid-driven modification of endocrine function, currently reported as lower testosterone levels, loss of libido, amenorrhea and infertility.
Indication
Opium and its derivatives are the most commonly used medications for the treatment of acute and chronic pain. Opium and its alkaloid-derivatives can also be used as tranquilizers, antitussives and in the treatment of diarrhea. The direct use of opium is not common nowadays but the use of some of its derivatives such as morphine and codeine, as well as the use of a tincture of opium for severe diarrhea can be seen in medical practice. Illegal use of opium has been registered to be for both recreational and medicinal purposes.
Half-life
The half-life of opium ranges between 3-10 hours.
Protein Binding
The protein binding of the alkaloids that form opium, such as morphine and codeine, can range from 20-60% depending on the specific alkaloid. The highest binding proteins for opium alkaloids are albumin and beta-globulin II.
Elimination
Opium is a mixture of different alkaloids including morphine and codeine. After a single ingestion of opium preparations, codeine and morphine can be found excreted in urine. The presence of codeine and morphine in urine seems to be detectable 2-12 hours and 2-36 hours post administration, respectively. The urinary excretion of morphine and codeine seems to be longer as the dose of opium is increased. After multiple dosages of opium, the presence of codeine and morphine in urine could be detected even after 48 and 84 hours post administration, respectively. After ingestion of poppy seeds, it is possible to collect morphine and codeine in urine 3-25 hours and 3-22 hours after administration, respectively.
Volume of Distribution
Opium presents a large volume of distribution that exceeds the total body water.
Effect Profile
Curated + 224 ReportsStrong euphoria and itching/nausea with moderate sedation, mild pain relief
Tolerance & Pharmacokinetics
drugs.wikiTolerance Decay
Demographics
Gender Distribution
Age Distribution
Reports Over Time
Effect Analysis
Erowid + BluelightEffects aggregated from 197 experience reports (147 Erowid + 77 Bluelight)
Effect Sentiment Distribution
Confidence Distribution
Positive Effects 65
Adverse Effects 42
Dose-Response Correlation
How effect frequency changes across dose levels
View data table
| Effect | Common (n=12) |
|---|---|
| Euphoria | 75.0% |
| Nausea | 75.0% |
| Sedation | 41.7% |
| Empathy | 33.3% |
| Stimulation | 33.3% |
| Tactile Enhancement | 33.3% |
| Dissociation | 33.3% |
| Anxiety Suppression | 25.0% |
| Hospital | 25.0% |
| Muscle Tension | 16.7% |
| Visual Distortions | 16.7% |
| Closed-Eye Visuals | 16.7% |
| Motor Impairment | 16.7% |
| Introspection | 16.7% |
| Music Enhancement | 16.7% |
Dose–Effect Mapping
Experience ReportsHow reported effects shift across dose tiers, based on 147 experience reports.
Limited tier coverage — most reports fall within the Common range. Effects at other dose levels may not be represented.
| Effect | Common (n=12) | |
|---|---|---|
| euphoria | ||
| nausea | ||
| sedation | ||
| empathy | ||
| stimulation | ||
| tactile enhancement | ||
| dissociation | ||
| anxiety suppression | ||
| hospital | ||
| muscle tension | ||
| visual distortions | ||
| closed-eye visuals | ||
| motor impairment | ||
| introspection | ||
| music enhancement | ||
| color enhancement |
Dosage Distribution
Dose distribution from experience reports
Real-World Dose Distribution
62K DosesFrom 141 individual dose entries
Oral (n=18)
Smoked (n=12)
Common Combinations
Most co-occurring substances in experience reports
Form / Preparation
Most common forms and preparations reported
Body-Weight Dosing
Dose relative to body weight from reports with weight data
Oral
Smoked
Redose Patterns
Redosing behavior across 115 reports
Opioid Equivalence (MME)
NIH HEAL 2024 & CDC 2022Opium 10 mg oral ≈ 10 mg Morphine oral (10 mg morphine per 1 mL liquid opium)