Morphine
Morphine is a potent opioid analgesic first isolated in the early 19th century by Friedrich Sertürner, with its name derived from Morpheus, the Greek god of dreams. Initially used for pain relief and to treat issues like alcohol abuse, morphine became widely available across Europe within two decades. In the United States, it was classified as a controlled substance in 1914 under the Harrison Narcotics Tax Act and is now considered the gold standard for assessing other analgesics. Morphine is effective for managing moderate to severe pain, both acute and chronic, and is often the active ingredient in many related medications, such as codeine. However, the widespread use of morphine has also led to significant issues with illicit opioid use, surpassing the prevalence of other illicit drugs like cocaine and heroin. Common side effects include decreased respiratory rate and sedation, which can become severely problematic, especially with overdose or chronic use. Additionally, the euphoric effects of morphine can lead to psychological dependence, and misuse, particularly through intravenous injection, poses serious health risks, including respiratory failure and infection. Withdrawal symptoms can occur in long-term users who abruptly stop using the drug, with physical discomfort that can last for weeks.
Morphine
DEFINITION: Morphine is a pure opioid agonist in the same class as oxycodone, hydromorphone, and fentanyl. The primary therapeutic action of morphine is analgesia. Like other pure opioid analgesics, the analgesic effects are limited only by adverse effects such as somnolence and depression and not by a ceiling of analgesic effect.
CATEGORY: Substances
STATUS: Legal in the United States and worldwide
CLASSIFICATION: Schedule II controlled substance
SOURCE: First isolated from the opium poppy, Papaver somniferum, in 1803
TRANSMISSION ROUTE: Exists as a tablet, capsule, powder, rectal suppository, oral suspension and solution, and solution for injection; ingested orally, snorted, or injected intravenously
History of Use
Morphine was first isolated in the early nineteenth century by Friedrich Sertürner in Germany. The word morphine is derived from the term morphium, for Morpheus, the Greek god of dreams. Within twenty years, morphine was available across Europe as an agent for treating pain and for many other uses, including treating alcohol abuse.
In the United States, morphine became a controlled substance in 1914 under the Harrison Narcotics Tax Act. Morphine is the gold-standard by which other analgesics are measured. The drug is legally prescribed for treating moderate and severe pain, both acute and chronic. Many available painkillers, such as codeine, are chemically related to morphine. Because of the legitimate pain-relieving properties of morphine, the drug is highly prescribed and used. This high level of use increases opportunities for diversion and abuse. Prescription morphine is available as an oral solution, immediate- or extended -release tablets, or extended release capsule. It may also be administered by injection into a vein, muscle, epidural space, or spinal canal.
Effects and Potential Risks
Decreased respiratory rate and sedation are two common adverse effects of morphine, effects experienced even in patients treated with normal doses and dosing regimens. However, these normal adverse effects can become extremely problematic and even fatal in acute morphine overdoses or with chronic administration. Respiratory depression occurs more commonly in older patients and in patients with underlying respiratory conditions, and it occurs to a higher extent with intravenous administration. Respiratory complications and sedative effects are also much more common in patients who are opioid naïve.
Like other mu (µ) opioid agonists (such as oxycodone and hydrocodone), morphine causes a feeling of euphoria, which can lead to psychological dependence. Following intravenous administration, euphoria can occur within five minutes, and although the physiological effects can last for greater than six hours, the feeling of euphoria generally dissipates sooner. This can lead an abuser to re-inject the medication at a time when their body is still reacting to the respiratory and CNS effects of the initial dose of morphine; this can lead to death. Intravenous injection also increases the risk of infection and vessel occlusion, both of which can have serious and fatal consequences.
Chronic morphine users who abruptly stop use can experience withdrawal. Signs and symptoms of withdrawal include nausea and diarrhea, profuse sweating, twitching muscles, and temperature disturbances, all of which can persist up to two weeks in some persons.
Bibliography
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“Morphine Injection.” MedlinePlus. US Natl. Library of Medicine, 15 Mar. 2025, medlineplus.gov/druginfo/meds/a601161.html. Accessed 27 Jan. 2025.
Murphy, Patrick B., et al. "Morphine." StatPearls, US Natl. Library of Medicine, NIH, 22 May 2023, www.ncbi.nlm.nih.gov/books/NBK526115/. Accessed 27 Jan. 2025.
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Tschacher, Wolfgang, Robert Hammig, and Nina Jacobsen. “Time Series Modeling of Heroin and Morphine Drug Action.” Psychopharmacology, vol. 165, 2003, pp. 188–93.