This document discusses receptor antagonists, opioid analgesics like morphine, and opioid antagonists like naloxone. A receptor antagonist blocks or inhibits a biological response by binding to and blocking a receptor. Morphine is an opioid analgesic that relieves moderate to severe pain by changing how the body feels and responds to pain in the brain. Naloxone is an opioid antagonist that rapidly reverses the effects of opioids like morphine, restoring normal respiration within 30 seconds by injection.

1. Pharmacology
lab 3
By:
Sheema omer qadr
Naschmil Abdulla Muhammed

2. Lecturer Name
A receptor antagonist is a type of receptor ligand or drug
that blocks or inhibit a biological response by binding to
and blocking a receptor rather than activating it like an
agonist. They are sometimes called blockers. Examples
include: alpha blockers, beta blockers, and calcium
channel blockers.
Kurdistan Technical
Institute(www.kti.edu.krd/ku) - Your Dept.
2
Drug antagonism

3. Lecturer Name
• Opioid analgesics: opioids are obtained from the juice
of the opium poppy. Their primary use is to relieve
intense pain and anxiety .Whether that pain is from
surgery or a result of injury or disease such as cancer.
• Morphine: is a medication that is used to relieve
moderate to severe pain. Morphine belongs to a class
of drugs known as opioid (narcotics) analgesics. It works
in the brain to change how your body feels and
responds to pain.
Kurdistan Technical
Institute(www.kti.edu.krd/ku) - Your Dept.
3

4. Lecturer Name
• Analgesia (relief of pain).
• Euphoria.
• Respiratory depression.
• Depression of cough reflex (antitussive property).
• Miosis.
• Emesis.
• GI tract (decrease GI motility).
• Cardiovascular (with large doses it causes bradycardia
and hypotension).
• Histamine release.
• Labor ( especially in second stage of labor)
Kurdistan Technical
Institute(www.kti.edu.krd/ku) - Your Dept.
4
Action of morphine

5. Lecturer Name
• Opioid Antagonist: administration of opioid antagonists
produces no profound effects in normal individuals.
However, in patient dependent on opioids, antagonists
rapidly reverse the effect of agonists (morphine).
Naloxone.
Naltrexone.
Nalorphine.
Kurdistan Technical
Institute(www.kti.edu.krd/ku) - Your Dept.
5

6. Lecturer Name
• Naloxone: It is used to reverse the coma and respiratory
depression of opioid overdose. Within 30 seconds of
administering IV injection of naloxone, the respiratory
rate and coma characteristic of high doses of morphine
are reversed, causing alertness.
• Naloxone has a half life of 30-90 minutes.
Kurdistan Technical
Institute(www.kti.edu.krd/ku) - Your Dept.
6

7. Lecturer Name
• Record the normal respiratory rate several times (as a
control) and observe the activity of the mice.
• Administer 0.5ml (or 1 ml) of morphine, record the
respiratory rate after 10 minutes.
• When respiration depresses, inject naloxone 0.4 mg and
record the respiratory rate again.
Kurdistan Technical
Institute(www.kti.edu.krd/ku) - Your Dept.
7
Procedure