All Drug's Pharmacokinetics Flashcards
Caffeine: about
religious drinks
- tea (china)
- coffee (ethiopia)
Caffeine: membranes
- simple diffusion to cross membranes and BBB
Caffeine: toxicity
- LD50 = 150 to 200 mg/kg BM
Caffeine: absorption
- RoA = ingestion
- absorbed by the stomach and small intestines within 45 mins of consumption
Caffeine: half life
t1/2 = approx 3 to 4 hours
Caffeine: metabolism
metabolised in liver by CYP450 enzyme system
Caffeine: metabolites
- paraxanthine
- theobromine
Caffeine: elimination
primarily eliminated through the kidneys and excreted through urine
Caffeine: potential for abuse and addiction
- very dependence-producing
- withdrawal effects caused by adenosine receptor density, and therefore adenosine sensitivity (depression, fatigue, irritability, headaches)
Nicotine: about
- alkaloid, organic compound from tobacco plant
- lipophilic free base
Nicotine: membranes
- simple diffusion to cross membranes and BBB
- environment pH affects its absorption (small intestine, not stomach)
Nicotine: toxicity
- cancer (90% of all lung cancers)
- COPD, asthma, emphysema
- LD50 = 30 to 60mg
Nicotine: absorption
- RoA = inhalation, ingestion, buccal, transdermal
- inhalation = most addictive
- transdermal = least addictive because of low dose and speed of delivery to the brain
Nicotine: half life
t1/2 = approx 2 hours
Nicotine: metabolism
metabolised in the lungs, kidneys, and liver by CYP450 and aldehyde oxidase enzyme systems
Nicotine: metabolites
cotinine (t1/2 = approx 16 hours)
Nicotine: elimination
primarily eliminated through the kidneys and excreted through urine
Nicotine: potential for abuse and addiction
- very dependence-producing (used as stress relief, weight control, social factor)
- withdrawal: irritability, anxiety, excessive hunger (blood sugar drop)
Alcohol (ethanol): about
fermentation of sugars, anaerobic respiration by yeast - changes the sugars into ethanol and carbon dioxide
Alcohol (ethanol): membranes
- simple diffusion to cross membranes and BBB
Alcohol (ethanol): absorption
- approx 80% absorption from upper intestine
- total absorption is unaffected by food in stomach
- avg vol of distribution is 0.54 l/kg
Alcohol (ethanol): half life
t1/2 = approx 3 to 5 hours but can vary
Alcohol (ethanol): metabolism
95% of alcohol is metabolized by alcohol dehydrogenase enzyme in the liver
Alcohol (ethanol): metabolites
- acetaldehyde first, broken down to acetate
Alcohol (ethanol): elimination
- liver (90%), and urine, sweat and breath
Alcohol (ethanol): potential for abuse and addiction
high potential for abuse based on its action in the glutamtergic, GABAergic, dopaminergic, and serotinergic systems
- withdrawal: tremors, irritability, nausea, anxiety, depression
Cocaine: about
- alkaloid
- from coca plant
Cocaine: membranes
- passive diffusion accross membranes and BBB