IDT - Drugs of Abuse, Ishmael Flashcards
The Continued, compulsive obsession with obtaining, consuming and experiencing the effects of self-administered drugs
Substance Dependence (addiction)
Drugs that have psychoactive properties have a ____________ which makes it __________ to be abused.
Positive reinforcing action
More Likely
The return to a drug use after abstinence
Relapse
What changes must be made in order to achieve continued recovery?
behavioral, social, psychological and physiologic changes
What area of the brain is responsible for the pathway in addiction?
Nucleus accumbens, projections from the Ventral Tegmental area.
Why are drugs that block dopamine receptors less likely to be self-administered?
They may have dysphoric effects that people would rather avoid.
What are the natural rewards that may be devalued and overriden in addictive pathways?
Food
Water
Sex
Nurturing
What is tolerance?
The decrease in pharmacologic response on repeated administration of the drug
What is sensitization?
Responses/side effects become stronger than previously anticipated.
Classification when administration of the drug is required to maintain normal function and avoid withdrawal syndrome.
Physiologic dependence
When a drug dependence is removed from a physically dependent person, this unwanted side effects might occur
Withdrawal syndrome
The process of by which an individual that is physically dependent on a drug is withdrawn from it
Detoxification
The 7 classes of drugs that have been recognized as obsessively self-administered by humans
Methylxanthines Nicotine Alcohol Marijuana Stimulants Opiates Hallucinogenic/Dissociative drugs
Nicotine
- Mechanism
- Effect
- likelihood of dependence
- Binds to Nicotinic Acetylcholine receptors
- Excitatory/Stimulant effect
- Dependence has a genetic component
Pharmacologic treatment strategies for smoking cessation
NRT - patches, gum, e-cig etc - Reduces withdrawal by changing behavior Anti Depressants (no SSRIs) - Bupropion - Nortriptyline Varenicline - Chantix, selective partial agonist
Varenicline (Chantix)
- Target
- Efficacy
Selective alpha4beta2 nicotinic receptor partial agonist
Causes sufficient dopamine release to reduce cravings/withdrawal but prevents full activation of receptor.
Why can Nicotine be so addicting?
Nicotinic receptors within the VTA and impact dopamine release in the nucleus accumbens
(mixes behavioral, cognitive and psychological signals)
How do Buproprion and Nortrtiptyline differ in their mechanism of action for smoking cessation
Buproprion targets NET and DAT
Nortriptyline (NET < SERT ««< DAT)
The observed phenomenon where the pharmacologic effect of alcohol having greater effect while rising than falling, even though blood ethanol concentration is the same.
The Acute Tolerance
or
Mellanby Effect
Effects of Alcohol on CNS
slurred speech motor incoordination impaired judgement uninhibited behavior increased self-confidence sedation relief of anxiety increased pain threshold
What is the first thing you lose during consumption of alcohol?
Cognitive functions, as the neuronal populations are more sensitive
Describe the Asian Glow
Asian populations lack aldehyde dehydrogenase or have a mutation which allows the alcohol’s aldehyde intermediate to build up and cause dysphoric effects.
Disulfiram
An inhibitor of aldehyde dehdryogenase, supposed to make people sick when they drink in order to ween bad drinking behaviors
Alcohol withdrawal symptoms
Tremors (Shakes) Increased BP Rapid Breathing Sweating/Nausea Alcohol Hallucinations Seizures Delirium Tremens
What class of medications can be used to lessen alcohol withdrawal symptoms
Benzodiazepenes
OTC - vitamins (thiamine, magnesium)
What is the main psychoactive ingredient in marijuana?
delta9-tetrahydrocanabinol
Why is marijuana not associated with severe withdrawal?
Not high enough dose to overload reward pathway and cause dependency
When did the Oregon Medical Marijuana Act get passed
Dec 1998; Approved for recreational use in Oregon in 2015
What debilitating medical conditions may be prescribed marijuana?
Agitation related to Alzheimer Cachexia Cancer Glaucoma HIV/Aids Nausea PTSD Severe Pain Seizures Persistent muscle spasms
How do endogenous cannabinoids modulate NT release
They decrease calcium ions by binding at CB receptors on the presynpatic neuron
Medicinal marijuana use vs
Recreational marijuana use
Medicinal - Symptom relief
Recreational - Pleasure
What routes of administration are often used for consumption of marijuana
Smoking
Oral (edibles)
Vaporizing
What route of marijuana consumption allows allows rapid and predictable bioavailabiity and allows for self-titration?
Smoking the Ganj
What is CUD?
Cannabis Use disorder
- pattern of substance abuse that leads to clinically significant impairment
- Social, occupational and recreational activities reduced in favor of drug
- tolerance, withdrawal may develop, causing behavioral and physical effects, persistence in spite of negative consequences just like other drugs
What medication was used to treat morphine addiction in 1884?
Cocaine
What legitimate medical use can cocaine be used for?
Local anesthetic and vasoconstriction (use dependent Na+ channel blocker)
- Upper respiratory tract
- ear
- nose
- throat
Cocaine’s mechanism of action
Binds to and blocks the Dopamine, SR and NE transporters, enhancing DA levels especially in the nucleus accumbens
What conditions can amphetamines be used to treat?
ADHD
Narcolepsy
Obesity
What is the primary effects of CNS stimulants?
Increased Alertness
Increased locomotor activity
Stereotype behavior, Euphoria, excitement, overconfidence and anorexia
What are the chances of developing dependence with amphetamine meds?
High, rapid, as it creates euphoria and is needed to avoid the unpleasant ftigue and depression that follows
What is the affect on dopamine transport by amphetamines?
Creates a “Reverse Transport”, because amphetamines act as substrates of NET, SERT, DAt and VMAT, they may deplete the pH gradient in vesicles and cause efflux of endogenous neurotransmitters.
What do Cocaine and SSRI’s/SNRI’s have in common?
They are both non-transported inhibitors, binding to the receptor but not being actively transported themselves.
What are the 3 types of ADHD?
Inattentive
Hyperactive-impulsive
Combined
In individuals that have been diagnosed with ADHD, what is the likelihood of dependence or abuse?
Much lower, and is considered safe, with no convincing evidence it may lead to this.
What is the effect of stimulants in treatment of ADHD?
Tends to reduce the hyperactivity, impulsiveness and works to improve the ability to focus.
How is Atomoxetine unique from other CNS stimulants?
It targets the NE transporter and inhibits its function rather than acting as a stimulant, so it has low abuse liability
