Predicting how Pharmacokinetic Drug Profiles Relate to Addictive Potential Flashcards
Predict how administrative route of cocaine and nicotine influences the speed of onset of CNS effects Explain how the metabolism of cocaine and nicotine contribute to their addictive potential
What are the most common routes of administration and their speeds of onset?
IV - 3 mins
Intra-nasal - 15 mins
Inhalational - 1.5mins
Oral - 60 mins
Why is inhalational faster than intravenous?
Because with inhalational it goes into pulmonary circulation then to the heart and into the systemic. With IV, it goes to vein, pulmonary, back to systemic. Also the alveoli are very well specialised for diffusion.
Describe where and how the metabolism of cocaine and nicotine take place.
They are both metabolised in the liver but cocaine can also be metabolised in the plasma too. Cocaine is metabolised by cholinesterase enzymes, nicotine is metabolised by cytochrome P450 enzymes. Nicotine half life 1-3 hours, cocaine 20-90 mins.
What properties make a substance addictive?
Fast onset as it forms a strong connection between taking the drug (inhaling) and feeling euphoria. Quick metabolism means that the high is lost quickly which leads to needing to take more to get the high back. Crack cocaine is the most powerfully addictive drug as it has a strong combination of both these properties which leads to drug seeking behaviour
