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Answer

As an opioid, Papaver somniferum and its derivatives cause miosis.

Background

The class of drugs derived from opium poppy plants and their structurally related chemical compounds are called opioids. For hundreds of years, derivatives of opioids have been used medicinally for their analgesic, somnolent, and antitussive effects, and they have been abused for their sedative and euphoric effects.

Opium Poppy Growing and Harvesting

PHOTO: Jason Hack (Oleander Photography)

According to Martin Booth’s 1999 book, Opium: A History, opium production from the plant varies depending on growing conditions, taking more than 2.5 acres of poppies to produce about 20 pounds of raw opium. Afghanistan is the world capital of opium.

When scratched, the pod of the plant (see photo) produces a milky latex called opium. This latex contains a variety of opioids, including codeine, morphine, thebaine, and papaverine.

Types

These active drugs are either derived unchanged from the plant (ie, morphine, codeine, and papaverine) or are altered natural derivatives; are “semisynthetic” opioids (ie, heroin, oxycodone, hydromorphone, and oxymorphone); or are fully synthetic compounds (ie, methadone, meperidine, fentanyl, and diphenoxylate). All work by interacting with receptors in the central nervous system, spinal cord, and peripheral nervous system. These effects are primarily a result of mu receptor agonism, but also from delta and kappa subtypes.

Overdose

In overdose, these medications cause unconsciousness and respiratory arrest leading to death. Cardiac symptoms can include palpitations, shortness of breath, syncope, bradycardia, hypotension, dysrhythmias, and cardiac arrest.

Antidote

There is an antidote, naloxone, that can be given for overdose. It binds to the opioid receptors, blocking their effects and reversing the central nervous system and respiratory depression. It can also precipitate opioid withdrawal, so naloxone should be administered carefully.

Dr. Hack (Oleander Photography) is an emergency physician and medical toxicologist who enjoys taking photographs of beautiful toxic, medicinal, and benign flowers that he stumbles upon or grows in his garden. Contact him at ToxInRI@gmail.com.