Administration

• Enteral


  When drugs are consumed through the gastrointestinal tract
• Parenteral


  When drugs are consumed without going through the gastrointestinal tract
• Drugs that enter the brain quickest are more likely to produce pleasurable feelings, and so more likely to be abused
• Oral administration


  Most common way of consuming drugs because of its convenience. Takes a long time to get full effects which means if you're dying it won't be able to save you, and you can puke it up so it leaves your system.
• Hepatic portal system


  Branch of the circulatory system that surrounds the gastrointestinal tract
• First-pass metabolism


  When liver enzymes destroy a certain amount of a drug when it enters the blood through the hepatic portal system
• Prodrugs


  Drugs that are inactive until after enzymatic processing
• Psilocybin


  Drug found in shrooms that is inactive until exposed to the highly acidic environment of your gastrointestinal system, when it becomes psychoactive
• Transbuccal 


  Drugs that are absorbed by vasculature in the gums like swedish snus
• Intravenous injection (IV)


  Fastest way of delivering drugs (within seconds) and doesn't get metabolized so the drug you give is the drug you get. Most effective medically (naloxone) and most likely to be misused (heroin)
• Narcan


  Naloxone, reverse the respiratory repressive symptoms of an opioid overdose
• IV injection disadvantages:

  • Cannot be removed from the blood without drugs or enzymes
  • Can deflate veins if done too frequently
  • Can transmit blood borne illnesses
• Intramuscular injections (IM)


  Take tens of minutes to soak in but are easier to administrate than IVs
• Subcutaneous injections (SC)


  Drug in injected into the fat layer directly underneath the skin, ideal for lipid-soluble solutions
• Inhalation


  Effects are within 10s of seconds once they reach your lungs and get into your bloodstream. Through smoking or vapor
• Cytochrome P450s (CYP)


  Enzymes that metabolize substances. Grapefruits inhibit them, which makes first-pass metabolism weaker, meaning prodrugs lose effect and the rest get more potent
• Inhalation sometimes has the advantage of losing effects almost immediately after administration stops because of how fast gas exchange is, so anesthesias can switch on and off
• Hypoxia


  Deficiency of oxygen in the blood stream that might result from damage to the airways during drug inhalation of hot burnt solids
• Insufflation


  Snorting. Breathing in powdered solids through the nose which enter the blood stream through the thin vessels there. Works quickly and bypasses the first-pass metabolism
• Transdermal


  Parenteral way of drug administration over a prolonged period through patches on the skin, like nicotine patches. Limited use because the skin is thick so only fatty lipids and small molecules effective at milligram concentrations are effective
• Topical


  Like transdermal administration but only affects the area that it's applied to. Doesn't get to brain so can't be psychoactive
• Ventral tegmental area (VTA)


  Midbrain. Synthesizes dopamine (largest group of DA cells in the brain, also called A10 neurons)