Chapter 16: Inhalants, GHB, and Anabolic-Androgenic Steroids Flashcards
What are inhalants?
Inhalants are abused substances that are often obtained from everyday household items. These substances are volatile liquids or gases at room temperature; are used by sniffing, inhaling, or spraying the substance; and do not belong to another defined class of abused drugs.
What are the categories of inhalant substances?
- volatile solvents
- fuels
- halogenated hydrocarbons
- anesthetics
- nitrites
How are inhalants absorbed?
They are rapidly absorbed from the lungs and readily enter the brain because of their high lipid solubility.
What are the behavioural effects of inhalants?
Low doses of volatile and gaseous inhalants produce effects resembling those seen with alcohol intoxication (e.g. euphoria, disinhibition, drowsiness). Users exposed to greater amounts of these substances show stronger depressant effects.
Explain the addictive potential of inhalants.
They can lead to tolerance, dependence, and an abstinence syndrome when drug use is stopped.
What are the neurochemical mechanisms of reward for inhalants?
They cause euphoric effects. They activate ascending dopaminergic systems, causing increased firing of VTA dopaminergic neurons and enhanced DA release in forebrain projection areas.
What are the neurochemical mechanisms causing the acute depressant effects of inhalants?
- enhanced activity of inhibitory GABA-A and glycine receptors
- inhibited activity of excitatory NMDA and nicotinic receptors
What effects does chronic inhalant use have?
- increased GABA-A receptor expression and function
2. decreased function and expression of NMDA receptors
What is GHB?
GHB is by-product of GABA metabolism (also called an analog). It is synthesized in the brain in small amounts and is thought to function as a neurotransmitter/ neuromodulator that may be coreleased with GABA at some synapses. It works on the GABAergic vesicles, transporters, and neurons.
Who us most likely to use GHB?
- attendees at dances and raves
- gay men
- bodybuilders
- date rape drug
How is GHB administered?
GHB is usually taken orally in the form of an aqueous solution. It is rapidly absorbed from the GI tract, enters the bloodstream, and crosses the blood-brain barrier.
What are the behavioural effects of GHB?
- mild euphoria
- relaxation
- social disinhibition
- enhancement of sexual arousal
- sedating effects (high doses)
- memory impairment (high doses)
- dizziness (high doses)
- nausea and vomiting (high doses)
- respiratory depression, unconsciousness, coma (high doses)
How does GHB function?
- low levels of GHB act on putative high-affinity GHB-specific receptors and extrasynaptic GABA-A receptors
- high levels of GHB activate GABA-B receptors
Describe the addictive potential of GHB.
Repeated GHB use can lead to tolerance, dependence, and withdrawal. Consumption patterns may escalate to dosing every 2 to 4 hours around the clock. In heavy GHB users, withdrawal symptoms can start within a few hours after the last dose and can persist for up to a few weeks.
What are anabolic–androgenic steroids (AAS)?
AAS are hormones that increase muscle mass and strength and also produce masculinizing effects in the user. These substances either contain the naturally occurring male sex hormone testosterone or are similar to testosterone in their chemical structure. Some AAS are taken orally, others by intramuscular injection.
What are the common AAS doping patterns?
- cycling
- pyramiding
- bridging
- stacking
Describe the AAS cycling administration pattern.
The steroid is taken in alternating on and off periods.
Describe the AAS pyramiding administration pattern.
The dose is increased during the early part of the cycle and then is gradually decreased after the peak dose is reached at the midpoint of the cycle.
Describe the AAS bridging administration pattern.
Bridging is a pattern that avoids periods of abstinence, since the user continues to take a low steroid dose in between the high doses of one cycle and the next.
Describe the AAS stacking administration pattern.
Combining two or more steroids (often one that is injected and another that is taken orally). Steroid users frequently practice polypharmacy, in which additional substances (e.g., stimulants or masking agents like diuretics) are taken along with the steroid.
What are the (positive) physiological effects of AAS?
- enhanced muscle fiber size
- enhanced muscle mass
- enhanced muscle strength
What are the adverse effects of AAS?
- cardiovascular problems
- renal toxicity
- skin and hair problems
- liver toxicity
- stunted growth
- masculinizing effects (women)
- disrupted reproductive function
- mood shifts and aggressive outbursts
Explain the addictive potential of AAS.
A certain percentage of steroid users develop a characteristic pattern of dependence and withdrawal. Feelings of anxiety are frequently experienced either at the end of a cycle or after a period of prolonged abstinence and withdrawal. Steroids are not as strongly reinforcing as classical addictive drugs like cocaine or heroin.
What are the medical uses of GHB?
- treating narcolepsy
2. treating alcoholism (reducing withdrawal symptoms)
