Physiology and Pharmacology Flashcards
Buprenorophine vs Methadone
Buprenorphine has advantages over methadone, including less associated stigma; fewer
regulations, which permit its use outside opioid treatment programs; and lower risk of overdose
(Albizu-Garcia et al., 2007). Its combination with naloxone reduces the likelihood of
intravenous abuse of the medication. Buprenorphine is safe and effective for alternate-day
dosing instead of daily dosing [Center for Substance Abuse Treatment (CSAT), 2004], which
may increase its patient adherence (Amass, Kamien, & Mikulich, 2000) and might make it less
likely to interfere with security procedures in a prison setting (Smith-Rohrberg et al., 2004). Finally, unlike methadone, which is ingested by swallowing under the observance of medical
staff, buprenorphine tablets are dissolved under the tongue.
Addiction in terms of brain anomalies
- A survival/reinforcement circuit involving an overactive “go” switch in the old brain
- A damaged or underactive “stop” switch in the control circuit in the new brain
- Impaired communication between these two circuitries
- Damaged, stay-stopped brain areas that make recovery extremely difficult
“Addiction comes from a combination of an obsession of the mind coupled with an allergy of the body.”
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Inhalation acts more quickly than any other method of use
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Stress can dramatically increase the ability of drugs to cross this barrier.
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The liver is the key metabolic organ - it breaks down or alters the chemical structure of drugs. Then the kidneys filter the metabolites, water and other waste from the blood and eliminate urine
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Old brain structure and function
Structure: brain stem, cerebellum, mid-brain, which contain the limbic system (emotional center).
Function: regulating physiological functions, experiencing basic emotions and cravings, imprinting survival memories. Acts four or five times more rapidly than the new brain – so action is usually well under way before common sense kicks in. Old brain simply reacts
New brain (neocortex) structure and function
Structure: cerebrum and cerebral cortex
Function: processes information coming from the old brain and from the senses via peripheral nervous system. Allows us to speak, reason, create, remember, make decisions and then act.
Memory and drug use
The more an activity is repeated, the more likely we are to repeat it when we run into a similar situation. The earlier in life a person begins using psychoactive drugs or practices addictive behaviors, the longer and stronger the memories remain in the brain. Brain tends to remember the positive memories more quickly and intensely than the negative ones (euphoric recall)
The “go” switch’s three functions + stop switch
- tells us that what we are doing is necessary for survival
- tells us to remember what we did to survive
- tells us “do more of whatever you did- do it again and again until you are satisfied; it is necessary for your survival”
- when need has been satisfied, the pain relieved or the imbalance rectified, the “stop” switch shuts doewn the “go” switch and the “do it again” message ceases
how the drug hijacks survival/reinforcement
“Go” switch more powerful than normal and the “stop” switch becomes dysfunctional. Essentially the individual is tricked into sensing that survival depends on their use.
With chronic heavy use, the “do it again” message becomes impossible to ignre– resulting in drug-seeking/using behavior regardless of the amount of pleasure the user experiences of the destruction the use ultimately causes. underlying message is “if you don’t do it again, you will die”
Endogenous neurotransmitter correlates mean that..
psychoactive drugs cannot create sensations or feelings that do not already have a ntural counterpart in the body
Down regulation
if the cell senses there are too many neurotransmitters (Which occurs with drug use), it retracts many of the receptor sites into the cell, causing a slowdown of message transmission. When drug use is stopped, most of the receptors will be restored. Excessive use, however, can cause a permanent decrease in receptor sites
Possible drug effects on neurotransmitters
- Block the release of neurotransmitters
- Force the release of neurotransmitters
- Prevent neurotransmitters from being reabsorbed
- Inhibit an enzyme that helps synthesize or metabolize neurotransmitters
- Interfere with the reuptake and storage
Withdrawal definition
Withdrawal is defined as the body’s attempt to rebalance itself after cessation of prolonged use of a pschoactive drug or compulsive behavior. Withdrawal effects are often the opposite of the drug’s direct effects