Drugs of Abuse Flashcards
What is tolerence?
Over time, with repeated doses of the drug, you need more drug to achieve the same effect. Very common.
Classic example = pain relief; eg codeine.
Sensitization is rare and very rarely seen.
What actually causes tolerance at the molecular level?
- Receptor Down Regulation
- Reduced receptor senstivity
- Increased compensatory mechanisms
How do drugs modulate the mesolimbic system?
The mesolimbic system controls reward/pleasure, and DOA’s modulate this by controlling dopamine levels.
- Direct Dopamine release from the nerve terminal (amp)
- Bind at DAT to block dopamine reuptake (coc + amp)
- Increasing DAT activity from mesolimbic disinhibition.
What are the three most important Neurotransmitters to know?
- DA dopamine
- GA GABA
- GL Glutamate
What is “withdrawal syndrome”
Evidence of physical dependance to a drug. Caused by the removal of the drug → CNS hyperarousal.
This can happen with alcohol, smoking or even caffeine.
Opposite effect to the drug itself
What are the specific symptoms of Opiod withdrawal Sydrome?
Craving, restlessness, irritability, inc. sensitivity to pain, nausea, muscle aches, insomnia, anxiety.
Due to an autonomic dysfunction: sweating, tachycardia, hypertension, nausea, vomiting, poops, fever.
What are the 3 factors which contribute to drug abuse?
Agent- the drug
Host- the user
Environment- the setting
In terms of the ‘agent’, drug itself what can cause addiction?
- Level of reinforcement (property that makes the user want to do the drug again!)
- Rapidity of onset
- Presence of withdrawal symdrome
- Convenient and effective method of administration
In terms of the ‘Host’ what can increase the chance of addiction?
**Personality: genetics, development, upbringing, social situations
Pharmacokinetics: eg; due to asian flush (alcohol → acetaladehyde) there’s a lower prevalence of asian alcholism
Pharmacodynamics
What are the important Drugs of Abuse to know about?
Alcohol
Opioids
Cannabis
propofol
cocaine
Amphetamines “p”
Alcohol as a drug of abuse.
- Works by GABA enhancement
- 5-10% (men) and 3-5% (women) addiction
- 90% hepatic metabolism 10% renal elimination
- Very soluble so quicly absorbed.
Alcohol at a low dose: mild sedation, motor inco-ordination, disinhibiton
Higher dose: sedation/anaesthesia
Tolerance, physical independence and withdrawal symptoms associated with alcohol?
Tolerance: decreased sedation but lethal dose unchanged
Physical dependance → early morning drinking
Withdrawal Syndrome: in ~50% alcoholics post cessation. (5% to delerium tremens, with 15% mortality)
What’s affected by chronic alcohol abuse
Liver Cirrhosis: fulminant hepatic failure GI bleed
Cardiac Failure: dilated cardiomyopathy, heart failure
Cushings Syndrome
Malnutrition, GI ulceration, GI cancer,
CNS effects: peripheral neuropathy
Fetal ETOH syndrome
What do you do?
- Check for danger
- Do the ABCDEs
*Make sure she’s breathing and the airway is clear.
- Admit to ICU (NOT jail as they will likely die)
- Airways and ventilation
- Dialysis
- Tests; blood ethanol, drugs
- Check for trauma (don’t assume its a singular cause)
Why is the opioid epidemic increasing?
Mainly due to medical intervention, with an increase in opioid prescriptions and funding was recently cut in the US. Dependent patient then looked to the black market to fuel their addiction