Inhalants freons

DPIs do not utilize Freon propellants, but use either with or without lactose as vehiculum. These devices have a clinical efficacy similar to standard metered-dose inhalers, but may be easier to use in selected patients, since a minimal inspiratory flow rate is necessary to inhale from a DPI. Therefore, the DPI may be difficult for patients with an insufficient inspiratory flow rate, which occurs in children, the elderly, people with severe COPD shared with diaphragm dysfunction, and during an exacerbation. The inspiratory flow rate is associated with the internal resistance of the device used. For instance the turbuhalor has a significant internal resistance and its delivered dose is dependent from the inspiratory flow rate. 

It is theorized that perch oroethylene increases the desorption of unsaturated and aromatic components that would not desorb into pure Freon 113. There were several reasons why the initial desorption was accomplished with 0.5 ml perchloroethylene and then brought up to 10 ml with Freon 113. Using a 2 cm infrared cell, perchloroethylene is not completely IR inactive in the region of interest. It has a weak peak at approximately 2870 cm- , which would cause problems if pure perchloroethylene were used. Secondly, use of Freon 113 lowers the inhalation hazard to the analyst. Table II lists the recoveries from charcoal tubes at different levels using the Freon 113/perchlo-roethylene mixture. 

Aerosol 17 (freon-free), 18 mcg/puff in 200 metered-dose inhaler 0.02% (500 mcg/vial) for nebulization Nasal spray 21, 42 mcg/spray Tiotropium (Spiriva)... 

Inhalant abuse can also be a hazard in some occupations. People who work in the refrigeration industry may abuse Freon, hydrocarbons used in refrigerants and people working in medical fields may abuse nitrous oxide. A 1979 study, Abuse of Nitrous Oxide, published in Anesthesia Analgesia, found that 20% of dental and medical students had abused nitrous oxide. 

Users should also avoid inhaling directly from a nitrous oxide aerosol can. Some users have died as a consequence of freezing the throat area because the heat is absorbed as the gas expands. Freon, a similar molecule used as an aerosol propellant, does not have nitrous oxide effects. 

Beclomethasone dipropionate is the 9-chloro-analogue of betamethasone dipropionate. It was developed by Glaxo and introduced in the United States by Schering Corp. for topical use in the treatment of asthma and allergic rhinitis by the inhalation of a freon-propelled aerosol. 

Aerosol spray cans arc pressurized with other organic chemicals. Until recently most aerosol products contained types of fluorocarbons known by the brand name Freon. Freon, when inhaled, prtiduces the same effects as the organic solvents and presents the... 

Inhaling aerosol propellants is a bit mure complicated than inhaling solvents because the propellants come mixed with other substances. For example when you press the button on a can of black spray paint, what comes out is a cloud of tiny droplets of black paint and gas. Inhaling black paint does not get you high and can make you very sick. Some users solve this problem by spraying the can into a bag or balloon so that the particles separate from the gas by adhering to the sides. Others turn the cans upside down so that only Freon comes out, and still others inhale the sprays through doth filters. 

Over 1,000 products are abused as inhalants. Users may initially choose an inhalant because of its availability, but most indicate individual preferences for certain chemicals. Sniffers will often choose a specific product to abuse, be it a brand of glue, correction fluid, gold or silver spray paint, or whippets. In some regional areas toluene is the most popular inhalant in others, gasoline and Freon. 

The modern pressurized metered dose inhaler (pMDI) was developed between 1955 and 1956. However, the pMDI had its roots in research carried out many years before.During the 1930s and 1940s, the discovery of liquefied propellants (chlorinated-fluorocarbons or freon propellants) such as CFC12, CFC114, CFCll, and CFC22 was a major step in the realization of a portable inhaler. However, the first pMDI was not invented until 1956, when the metering valve used in the device was developed and patented. ... 

Freon 11 up to 4.53 pg/ml and of Freon 12 up to 4.73 pg/ml were measured after two inhalations. It was concluded that a toxic concentration could only be reached if the aerosol was taken on every breath for over 12 consecutive breaths (3). 

Deliberate ocular exposure in rabbits to liquid Freon 12 produced effects related to the duration of exposure. Severe corneal damage with opacity occurred following exposure for 30 s. In dogs, inhalation of fluorinated hydrocarbon vapors causes bradycardia... 

Brady WJ, Stremski E, Eljaiek L, Aufderheide TP. Freon inhalational abuse presenting with ventricular fibrillation. Am JEmergMed 1994 12(5) 533-6. 

Freons may pose a health hazard if inhaled in large amounts. They displace oxygen in the air, causing dizziness, drowsiness, irregular heartbeat, cardiac arrest, unconscious-... 

A. Freons are mild CNS depressants. They may also displace oxygen from the air, causing hypoxemia. Freons are well absorbed by inhalation or ingestion and are usually rapidly excreted in the breath within 15-60 minutes. 

A. Inhalation. The toxic air level is quite variable, depending on the specific agent (see Table IV-4, p 532). Freon 21 (dichlorofluoromethane TLV 10 ppm [42 m m ) is much more toxic that freons 12 and 22 (TLV 1000 ppm). In general, anesthetic or CNS-depressant doses require fairly large air concentrations, which can also displace oxygen, leading to asphyxia. The air level of dichloromonofluoromethane considered immediately dangerous to life or health (IDLH) is 5000. Other TLV and IDLH values can be found in Table IV-4 (p 532). 

The pressurized metered-dose inhaler (pMDI) for the delivery of antiasthma drugs originated in the U.S. cosmetic industry. George Maison, the president of Riker Laboratories, and Irvin Porash, who worked in Riker s pharmaceutical development laboratory, are credited with the development of the first pMDI (32). Experiments were conducted to formulate pressurized aerosols of isoproterenol and epinephrine, which had been dissolved in alcohol, using the freon propellants 12 and 114. 

The most common errors are the inability to coordinate inhalation with MDI actuation, to inhale too quickly, and to exhale without a breath-hold (12,49,50). Crompton (49) identified 215 patients with inadequate inhaler technique. Of these, 50% failed to synchronize aerosol release with inhalation and 36% stopped inhaling when the propellant spray hit the back of the throat. Patients may stop breathing in when propellants impact on the back of the throat and rapidly evaporate, causing almost instantaneous cooling in that area. This is known as the cold freon effect (51). It is difficult to argue with the advice that old patients, young patients, and anyone else should be assumed to be unable to use pMDIs properly unless proved otherwise (49). Nasal inhalation is also a common error among children (51). 

The discovery of the harmful effect of CFCs on stratospheric ozone resulted in the elimination of CFCs from aerosol spray cans (with the exception of essential medical uses such as asthma inhalers) and refrigeration systems. It was also discovered that similar bromine-containing compounds called halons that were used in fire extinguishers posed the same threat as Freon. 

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