Triad of Symptoms:
respiratory depression, miosis and coma
How do you treat respiratory depression in opioid agonist toxicity?
Give Naloxone = competitive opioid receptor antagonist
Can Naloxone precipitate withdrawal?
- Thus, careful titration of the dose to reverse respiratory depression will reduce the possibility of eliciting full-blown abstinence syndrome.
How does the DOA of Naloxone compare to most opioid agonist?
Naloxone’s DOA is shorter acting
What are the psychostimulants?
Cocaine, Methamphetamine, Methylphenidate
What are the subjective-Behavioral Effects of Psychostimulants?
- Very intense and reinforcing euphoria
- Euphoria characterized by heightened awareness, arousal, elation, improved performance on tasks of vigilance and alertness, and greater self-esteem
- Repeated dosing produces involuntary motor activity, stereotyped behavior and anxiety, which can progress into acute paranoid psychosis during extended, uninterrupted 'runs'
- (Particularly with amphetamine-like drugs)
Chronic use of psychostimulants can cause what?
Nneurotoxicity, resulting in semi-permanent behavioral changes similar to schizophrenia, e.g. paranoid ideations, hallucinations, hostility, memory impairment and difficulty in concentrating.
Doe psychostimulants have a fast or slow onset?
Rapid onset with IV/Inhaled
Why do pychostimulants have a high abuse potential?
Intense and reinforcing euphoria, resulting in a very high abuse potential.
Stimulants cause dose-dependent increases in what?
HR and BP
Because stimulants cause a dose dependant increase in HR and BP, what are SEs that can result?
Arrhythmias, myocardial ischemia, coronary and cerebral vasospasm, hyperthermia and seizures
Death from Stimulants is due to what?
What type of treatment is available for stimulant induced Arrhythmias, myocardial ischemia, coronary and cerebral vasospasm, hyperthermia and seizures?
Treatment is supportive
What is the standard of care for treating high dose cocaine users?
Antidepressants to reduce depression associated with abstinence
Tolerance to stimulants develops rapidly to what effects?
What is the plasma half-life for cocaine?
~ 50 minutes
About how much time elapses before an Intranasal/inhalation/I.V. cocaine user desires more?
What is characteristic use of methampetamines/cocaine?
- A binge pattern of abuse develops characterized by dose escalation and uninterrupted use that continue for days until supply runs out
- Called a Run
- Food intake, sleep and social responsibilities are ignored
Physical Dependence following a run with stimulants has what characteristics?
- Withdrawal or 'crash' ensues characterized by 'craving', dysphoria, depression and sleepiness/fatigue
- Can last from 1-3 weeks in highly dependent individuals
What is the psychoactive chemical/reinforcing agen in Marijuana?
- Delta- 9 -tetrahydrocannabinol (Delta9-THC)
- A cannabinoid agonist
Where are cannabinoid receptors located?
High density in the cerebral cortex, hippocampus, striatum (same as nucleus accumbens) and cerebellum
What is the endogenous ligand for cannabinoid receptors?
Thought to be an arachidonic acid derivative called Anandamide
What is the peak and DOA of marijuana when smoked?
- Readily absorbed, resulting in rapid onset
- Peak within 30 minutes
- Last for several hours
What are the reinforcing effect of marijuana?
- Marijuana causes euphoria characterized by a sense of well-being and feelings of happiness that is followed by drowsiness
- Perception of time is altered along with distortions in hearing and vision
Why do subjective effects of marijuana vary among individuals?
They are a function of dose, experience/expectations and setting
Under what conditions are Anxiety/panic reactions are reported with marijuana use?
In inexperienced users or following use of large quantities
What are the Physical-Physiological Effects of using marijuana acutely?
- Impairment of cognitive and motor skills needed to complete complex tasks
- Vasodilation (conjunctival reddening)
- Lowered intraocular pressure
- Appetite stimulation
- Orthostatic hypotension in large doses
How many reports of lethal overdose for marijuana are made each eyar?
No reports of fatal overdose with marijuana
Chronic use of marijuana has what negative effects?
Negatively affects short-term memory
Under what conditions does tolerance develop to marijuana’s effects?
After frequent use at high doses
Physical Dependence to marijuana happens at what interval?
Develops in subjects taking high doses for several weeks
Abrupt cessation to marijuana use results in what effects?
Mild abstinence syndrome characterized by insomnia, irritability, anorexia, increased sweating and mild nausea
Does moderate use or marijuana cause physical dependence?