Narcotic Analgesic PDF

# NARCOTIC ANALGESIC ## Use - For relief of pain (moderate to severe) without loss of consciousness - With addictive property ## Types - **Opiates**: natural - **Opioids**: both natural opiates & synthetic drugs with similar action (narcotic analgesic) - alkaloids: from juice of opium poppy se...

# NARCOTIC ANALGESIC ## Use - For relief of pain (moderate to severe) without loss of consciousness - With addictive property ## Types - **Opiates**: natural - **Opioids**: both natural opiates & synthetic drugs with similar action (narcotic analgesic) - alkaloids: from juice of opium poppy seed (*papaver somniferum*) - **Natural**: - Morphine - Codeine (methylmorphine) - Thebaine ## Mechanism of Action - Acts on opioid receptors found in the CNS: 1. Limbic system (hypothalamus) 2. Medial & lateral thalamus 3. Areapostrema/chemotremoregulatory zone (CTZ) - area of vomiting 4. Nucleus of solitary tract - area of coughing 5. Substancia gelatinosa ## Drugs Acting as Agonists ### I. Morphine #### Effects: (HECk of a DREAM) - **H**: Histamine release - urticaria (pruritus)/itchiness - Brochoconstriction - **E**: Mesis (vomiting) - **C**: Cardiovascular - hypotension (orthostatic) due to ↓ 02 in brain - **D**: - Depression of cough reflex (antitussive) - Depression of CNS (sedative) - Decrease GI motility (constipation) - **R**: Respiratory depression - **E**: Euphoria - feeling of happiness, confidence, or well being sometime exaggerated in pathological states as in mania - **A**: Analgesia (relieve pain) - **M**: Miosis (pinpoint/constricted pupil) ## Uses - **Analgesia**: Drug of Choice (DOC) for moderate to severe pain - **Before**: Tincture of opium; diphenoxylate + atropine (Lomotil) - **Now**: Loperamide - **Diarrhea**: - **Before**: Codeine (AC)/methylmorphine - **Now**: Dextromethorphan - less addicting - **Antitussive**: ## Adverse Drug Reaction - Tolerance (larger doses needed) - Dependence/addiction ## Poisoning Triads of Morphine 1. Coma 2. Miosis (pinpoint pupil) 3. Respiratory depression #### Treatment: - Naloxone #### Management: - Check RR, depth & rhythm - Withold: If RR is 8-10 bpm or ↓ ## II. Meperidine/Pethidine (Demerol) ### S/E - Respiratory depression - Physical dependence - Bronchospasm - Atropine like effect/Mydriasis (pupil dilation) ## III. Fentanyl (Sublimaze) - Most potent opioid analgesic - 80x more potent than morphine - + Droperidol (Innovar) - use for **NEUROLEPTANALGESIA** - An intense analgesic and amnesic (quiescence) state produced by the combination of narcotic analgesics and neuroleptic drugs. Mainly used as anesthetic drug. ## IV. Nalbophine (Nubain) ## IV. Others | Drug | | |-------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------| | Pentazocine | | | Hydrocodone | | | Hydromorphone | | | Propoxyphene | | | Buprenorphene| | | Heroin | Diacetyl morphine - hydrolyzed to morphine - crosses BBB (blood brain barrier) more quickly | ## Drugs Acting as Antagonists/Antidote against Narcotic Poisoning 1. Naloxone (Narcan) 2. Naltrexone (Revia) 3. Nalmefene (Revex) # OPIOIDS BY MECHANISM OF ACTION | Drug | |-------------| | Morphine | | Heroin | | Methadone | | Hydromoprphone| | Meperedine | | Fentanyl | | Alfentanyl | | Sufentanyl | | Codeine | | Oxycodone | | Propoxyphene | | Dextromethorphan| | Diphenoxylate | | Difenoxin | | Loperamide | | Pentazocine | | Nalbuphine | | Butorphanol | | Buprenorphine | | Naloxone | | Naltrexone | | Nalmefene | ## Adverse Effects of Opioids 1. **CNS** - **Reasons:** Opioids cross the BBB - **Manifestations:** - Drowsiness to sleep to unconsciousness - Decreased mental & physical activity - Headache - Dizziness - Confusion - Dysphoria - An emotional state characterized by anxiety, depression, or unease. - Unusual dreams - Hallucinations - Delirium - Interferes with accurate judgment and ability to operate machinery & drive 2. **Respiratory** - **Reason:** Medullary depression - **Manifestations:** - Respiratory depression - slow, shallow respirations to respiratory arrest - Decreased response to carbon dioxide - Antitussive activity 3. **Cardiovascular** - **Reasons:** Direct dilation of peripheral blood vessels, reducing ability of cardiovascular system to respond to gravitational changes - **Manifestations:** - Orthostatic hypotension 4. **Gastrointestinal** - **Reasons:** - Diminished peristaltic contractions in small & large intestine and delay pf passage of gastric contents through the duodenum - Increased smooth muscle contraction - Increasing pressure in biliary ductal system - Stimulates chemoreceptor zone in medulla (CTZ) - **Manifestations:** - Constipation - Biliary colic - is pain associated with irritation of the viscera secondary to cholecystitis and gallstones - Nausea & vomiting 5. **Genitourinary** - **Reason:** Increased smooth muscle contraction - **Manifestations:** - Ureteral spasm - Spasm of urinary spinchter - Urinary retention or hesitancy (especially in patients with prostatic hypertrophy) - Oliguria - Antidiuretic effects - Decreased libido - Prolonged labor - Respiratory depression in neonate 6. **Other Effects** - **Reasons:** - Pupillary constriction - Stimulate release of antidiuretic hormone, prolactin, human growth hormone - Physical dependence - **Manifestations:** - Blurred vision - Dry eyes - Hypersensitivity reaction: urticaria, skin rash, itching or wheal formation@site of injection - **Withdrawal Symptoms: (with dependence on drug/alcohol)** - Sweating - Tremor - Vomiting - Anxiety - Insomnia - Muscle pain - Tolerance