All are seen in morphine poisoning except –
**Core Concept**
Morphine poisoning, also known as opioid overdose, is a medical emergency caused by excessive ingestion of morphine, a potent opioid analgesic. This condition can lead to respiratory depression, coma, and even death if left untreated. The underlying pharmacological principle is the central nervous system depression caused by morphine's action on opioid receptors.
**Why the Correct Answer is Right**
Morphine poisoning typically presents with symptoms such as respiratory depression, sedation, miosis (pupil constriction), and bradypnea (slow breathing rate). These symptoms occur due to morphine's action on the mu-opioid receptors in the brain, which decreases the inhibitory neurotransmitter GABA and increases the excitatory neurotransmitter glutamate. This results in a decrease in the respiratory drive, leading to respiratory depression. The correct answer will be the option that is not typically seen in morphine poisoning.
**Why Each Wrong Option is Incorrect**
**Option A:**
* This option is incorrect because tachypnea (rapid breathing rate) is not a typical symptom of morphine poisoning. Morphine actually causes respiratory depression, leading to bradypnea.
**Option B:**
* This option is incorrect because hypertension (high blood pressure) is not a characteristic finding in morphine poisoning. Opioids can cause hypotension (low blood pressure) due to vasodilation.
**Option C:**
* This option is incorrect because hyperthermia (elevated body temperature) is not typically associated with morphine poisoning. Opioids can actually cause hypothermia (low body temperature) due to decreased metabolic rate.
**Option D:**
* This option is incorrect because seizures are not a typical symptom of morphine poisoning. Opioids can cause sedation, but seizures are more commonly associated with withdrawal or with other substances.
**Clinical Pearl / High-Yield Fact**
A key distinguishing feature of opioid overdose is the presence of miosis (pupillary constriction). This is a classic clinical sign that can help diagnose morphine poisoning.
**Correct Answer: A. Tachypnea**