This program is brought to you by Emory University. >> Today I'm going to talk about the inhalants. I won't be able to discuss all of the inhalants, but I'll select some so that you will gain an understanding about this group of substances. Inhalants are usually liquids or gasses and the fumes are inhaled for their effects. They're found in paints, glues, fuels, and many other products. These substances are legal, very available, and they have rapid effects. Surveys show that a significant number of people use these drugs. Unfortunately, they are addicting and quite dangerous, particularly after long-term use. The inhalants are a very diverse group of substances. It's because they are classified not on the pharmacological properties, not on the receptors that they stimulate, but on the fact that they are volatile and gaseous. Therefore, they will have different properties and mechanisms depending on the substance we're considering. Our first group includes the solvents, which are found in many materials including glue, paints, paint thinners, and motor fuels. Nitrous Oxide, an anaesthetic gas, is a widely abused inhalant. Outside of medical and dental practices, it's found in whipped cream chargers and it does cause laughing, hence it's name, laughing gas. Another group of inhalants include the alkyl nitrites that are found in room deodorizers. Other inhalants are found in propellants like hairspray, and in fuels like cigarette lighter fluid. This image shows the chemical structures of some of the inhalants. As I said, many are readily available and include Toluene, which is very common. Trichloroethylene, ether, nitrous oxide, and others. We can look at the inhalants as a class and make some general comments about their acute effects. By acute I mean first time effects. First, there is an excitation, which many refer to as a rush. This is then followed by depression. They produce an apparent drunkenness caused by disruption of mental processes, loss of coordination, and slurred speech. They irritate the eyes and the lungs, and higher concentrations can produce hallucinations, seizures, a coma, and even death. A rare but lethal condition that can occur even after a single first use is something called sudden sniffing death. It's believed to be due to cardiac arrhythmias and stress, if this occurs it can be quite a shock to a family in a group. These can be very dangerous substances. Anesthetics, another group of inhalants, produce a relaxation, anesthesia, and amnesia. One can imagine that these effects would reduce stressful feelings felt by the user for whatever reason. As we have said previously, stress is a common factor in drug abuse. Having discussed the acute effects, we can now consider the effects that are found after long term use of the inhalants. General long term effects of inhalants are very serious. They include brain damage resulting in shrinkage of some areas. Brain imaging has shown this. There's also damage to the bones, heart, kidneys, and lungs, and an increase in the risk for many other illnesses. There's great concern about these toxicities, given that inhalants are often abused by children and adolescents. How do inhalants work? Well, as I mentioned, this is a very diverse class of drugs. And because of that, there are many different mechanisms that we have to consider. Different drugs have different mechanisms. Toluene, a very commonly used inhalant found in paints and paint thinners, causes a generalized depression of the brain, mainly by inhibiting excitatory neuro, neurotransmitter receptors. And by enhancing inhibitory neurotransmitter receptors. There may be actions of other receptors as well. When we're considering the anesthetics, many enhance inhibitory neurotransmitter receptors such as GABA-A and Glycine receptors. Nitrous Oxide is also thought to inhibit the excitatory neurotransmitter receptor, the NMDA receptor. So it's clear that these substances have a variety of actions. Although for some, there are common themes in their actions. A common theme is the reduction or blockade of excitation, and the enhancement or the increasing of inhibition at synapses in the brain. Treatment is of course available for those abusing inhalants. Because of the serious nature of the long term effects of the drugs, stopping use is obviously beneficial. Although treatment's available, there are no proven treatment medications specific for inhalant abuse at this time. Therefore, an important approach is to treat the symptoms and signs that occur with each specific inhalant in each patient, including counseling with education about the substances. As with many drug abusers, there are often coexisting mental or physical problems in a given patient. Treatment programs for the addict should include addressing these other co-existing mental and physical disorders. We can close by restating what I said at the beginning of the lecture. Inhalants are easily obtained, easily, easily used, but addicting and very toxic. Cessation of use is most important.
