Blog > The Pre-Med Podcast > Behavioral Science and Psychiatry > Narcotics

Narcotics

  • Natural narcotics come from opium
  • Opium comes from Papver somniform
  • Meaning of opium: poppy juice
  • Induce sleep and eliminate pain
  • Only two natural narcotics that come from opium: morphine and codeine
  • Semisynthetic narcotics come from manipulation of morphine and codeine
  • Synthetic narcotics are not derived from natural opiates at all

- Methadone

- Phentanyl

- Darbone

  • Opiod/Narcotic antagonists

- Naloxone short t1/2

- Natrexone longer t1/2

- Nalmephene moderate t1/2

Opiod receptors

  • Mu
  • Kappa
  • Delta

Epidemiology

  • Herion is the most widely abused opiate
  • .7% of the adult population has met the diagnostic criteria for opiod abuse or dependence
  • Urban black, Puerto Rican, and Chicano males are the ones who primarily use heroin
  • Male:female ratio: 3 to 1

Patterns of Use

  • Heroin is virtually never taken by mouth
  • Novices may snort it
  • In mid- and far- eastern countries, people may smoke it
  • Majority of heroin users inject it SC, IM, or IV
  • IV route is very popular b/c of the instant effects

Effects of Heroin

  • Thrill, kick, or flash – not developed by everyone; orgasmic feeling felt most in epigastrium; does not last more than a minute or two; often do it so much that lose vein
  • Release of ↑↑↑↑ histamine:

- Itching – can be a very bad reaction

- Reddening of the eyes

- Hypotension- can be an emergency (anaphylactic reaction)

  • Heavy sedation may be present
  • Sometimes prominent, vivid dreams
  • Euphoria
  • Anxiety, worries, sexual desires are absent
  • Body is warm; sweating is profuse
  • Initially nausea and vomiting may be present
  • Reduced sensitivity to the respiratory medullary center to CO2 is reduced (dose related)
  • Spasmogenic effect of smooth muscles
  • Enhances secretion of ADH – ↓ urination
  • Gonadotropin secretion may be interrupted
  • Sexual desires minimal or absent
  • Penile erection possible
  • Ejaculation delayed or absent

Distribution and Metabolism of Heroin

  • IV heroin disappears rapidly
  • Half-life is about 2.5 minutes
  • Heroin 6-monoacetylmorphine morphine excreted thru the kidneys

Tolerance to Heroin

  • When heroin is used regularily, tolerance to many of it effects develop rapidly, but tolerance is incomplete
  • Very little effect to its constipating effect develops and only partial tolerance to its miotic effects

Acute intoxication

  • Triad:

1. Pinpoint pupils (CONSTRICTED)

2. Depressed repiration

3. Coma

  • Other manifestations include:

- Pulmonary edema

- Cardiac arrhythmias

- Convulsions, esp with codeine, propoxyphene (Darvon) or meperidine (Demerol)

  • Annual death rate 16/1000
  • Most of the death due to OD
  • Anaphylactic reaction

Opiate OD: Treatment

  • Supportive treatment

- Clear airway

- Artificial respiration

- Treat hypotension

- Treat arrhythmias

- Positive pressure oxygen

- Narcotic antagonist:

Naloxone .4 mg to 1mL q 2-3 hrs as needed

- Monitor 24 + hrs

Clinical Picture of Acute Withdrawal from Narcotics

  • Take into consideration the:

- Half-life of the drug

- Dosage

- Length of time that the patient has been using the drug

  • The first manifestations are almost classical manifestations of influenza, plus a craving for more narcotics (lacrimation, rhinorrhea, sweating, ↑ temp, ↑RR, tachycardia)
  • Later on, the manifestations are characterized by gastrointestinal upset (nausea, vomit, diarrhea); PUPILS DILATED; won’t sleep

Protracted Abstinence

  • Acute abstinence phase is followed by a more protracted abstinence lasting 30 wks or more

Opiate Withdrawal

  • Characterized by sympathetic hyperactivity (↑↑ NE)