Substance Misuse Flashcards
What are the two mechanisms of substance misuse?
Tolerance and Reward
Tolerance is the basis of physical dependence, while Reward is the basis of psychological craving.
Define Tolerance.
Reduced responsiveness to a drug caused by previous administration.
List examples of drugs that develop tolerance.
- Opioids
- Ethanol
- Barbiturates
- Benzodiazepines
What is dispositional tolerance?
Less drug reaching the active site due to factors like less absorption or faster metabolism.
What are the types of drug metabolism in dispositional tolerance?
- Increased rate of metabolism to inactive metabolites
- Decreased rate of metabolism to active metabolites
Define Pharmacodynamic/Functional tolerance.
Drug has less action at the active site due to fewer or less efficient drug receptors.
What can the development of tolerance lead to?
Withdrawal symptoms.
Describe the adaptive response of the body to drug effects.
The body initiates a response to maintain homeostasis, e.g., increased sensitivity to neurotransmitters.
What is the reward pathway?
Neurones projecting from the ventral tegmental area (VTA) to the nucleus accumbens and prefrontal cortex.
How does stimulation of VTA neurons affect dopamine levels?
Releases dopamine causing a sensation of pleasure/reward.
Which drugs act on the reward pathway producing craving?
- Heroin
- Amphetamine
- Cocaine
- Alcohol
What are the key issues related to drug risk?
- Type of drug and effect
- Purity, dose, strength, tolerance
- Route of administration
- Legal status
- Comorbid health conditions
- Likelihood of dependency
- Method of purchase
List symptoms of opiate withdrawal syndrome.
- Craving
- Insomnia
- Yawning
- Muscle pain and cramps
- Increased salivary, nasal, and lacrimal secretions
- Marked dilated pupils
- Piloerection
What is the classification of stimulant drugs?
- Cocaine
- Amphetamine
- Methamphetamine
- Methylphenidate
What are common opiates?
- Opim
- Morphine
- Heroin
- Methadone
- Codeine and Dihydrocodeine
