Drugs of Abuse: Pharm

Question 1

tolerance vs. dependence

Answer 1

tolerance: reduced response to stimulus. need more for the same effect.
dependence: need drug to feel normal

Question 2

factors that influence long-term addiction.

Answer 2

dopanine increases cAMP levels
stimulates CREB
CREB activates genes that feed into the VTA center. this dampens VTA activity. With less VTA activity, there is less dopamine in the accumbens: lowered reward from the stimulus. this is tolerance: increased drug taking.
abstinence lessens tolerance but increases sensitization and craving due to delta FosB
delta fosB rises after long term drug use and are stable for weeks to months. also increases after natural reinforcing behaviors

Question 3

opiate addiction: molecular level

Answer 3

opiates bind receptors
cyclic AMP is reduced
over time, sensitivity of receptor goes down (tolerance). More cyclase is also made to compensate for chronic inhibition. With desensitization, cyclase is less inhibited and relatively more cAMP is made
upon withdrawal, inhibitory activity is lost: LOTS of cAMP. leads to craving

Question 4

disulfram

Answer 4

for EtOH addiction
chelator
reduces activity of alcohol dehydrogenase
increases hangover

Question 5

What opiate receptor antagonists are used?

Answer 5

naloxone and naltrexone. naloxone is IV administration.

Question 6

buprenorphine

Answer 6

partial mu agonist

reduced addiction potential

Question 7

clonidine

Answer 7

alpha 2 agonist

supresses symptoms of opiate/benzo withdrawal

Question 8

topiramate

Answer 8

anti-seizure and anti-migraine drug that may reduce cravings. mechanism is unknown. may cause weight loss

Question 9

buproprion

Answer 9

reduces nicotine cravings