Inhaler
Encyclopedia
Asthma
Asthma is the common chronic inflammatory disease of the airways characterized by variable and recurring symptoms, reversible airflow obstruction, and bronchospasm. Symptoms include wheezing, coughing, chest tightness, and shortness of breath...
and Chronic Obstructive Pulmonary Disease
Chronic obstructive pulmonary disease
Chronic obstructive pulmonary disease , also known as chronic obstructive lung disease , chronic obstructive airway disease , chronic airflow limitation and chronic obstructive respiratory disease , is the co-occurrence of chronic bronchitis and emphysema, a pair of commonly co-existing diseases...
(COPD). Zanamivir (Relenza), used to treat influenza, must be administered via inhaler. To reduce deposition in the mouth and throat, and to reduce the need for precise synchronization of the start of inhalation with actuation of the device, MDIs are sometimes used with a complementary spacer
Asthma spacer
An asthma spacer is an add-on device used to increase the ease of administering aerosolized medication from a "metered-dose inhaler" . The spacer adds space in the form of a tube or “chamber” between the canister of medication and the patient’s mouth, allowing the patient to inhale the medication...
or holding chamber device.
Metered-dose inhalers
MDI — The most common type of inhaler is the pressurized metered-dose inhaler (MDI). In MDIs, medication is most commonly stored in solution in a pressurized canister that contains a propellant, although it may also be a suspension. The MDI canister is attached to a plastic, hand-operated actuator. On activation, the metered-dose inhaler releases a fixed dose of medication in aerosolAerosol spray
Aerosol spray is a type of dispensing system which creates an aerosol mist of liquid particles. This is used with a can or bottle that contains a liquid under pressure. When the container's valve is opened, the liquid is forced out of a small hole and emerges as an aerosol or mist...
form. The correct procedure for using an MDI is to first fully exhale, place the mouth-piece of the device into the mouth, and having just started to inhale at a moderate rate, depress the canister to release the medicine. The aerosolized medication is drawn into the lungs by continuing to inhale deeply before holding the breath for 10 seconds to allow the aerosol to settle onto the walls of the bronchial
Bronchus
A bronchus is a passage of airway in the respiratory tract that conducts air into the lungs. The bronchus branches into smaller tubes, which in turn become bronchioles....
and other airways of the lung.
Dry powder inhalers
DPI — Dry powder inhalerDry powder inhaler
A Dry powder inhaler is a device that delivers medication to the lungs in the form of a dry powder. DPIs are commonly used to treat respiratory diseases such as asthma, bronchitis, emphysema and COPD although DPIs have also been used in the treatment of diabetes mellitus.DPIs are an alternative...
s release a metered or device-measured dose of powdered medication that is inhaled through a DPI device.
Nebulizers
NebulizerNebulizer
In medicine, a nebulizer is a device used to administer medication in the form of a mist inhaled into the lungs....
s — supply the medication as an aerosol created from an aqueous formulation.
Analgesic inhalers
In 1968, Robert Wexler of Abbott LaboratoriesAbbott Laboratories
Abbott Laboratories is an American-based global, diversified pharmaceuticals and health care products company. It has 90,000 employees and operates in over 130 countries. The company headquarters are in Abbott Park, North Chicago, Illinois. The company was founded by Chicago physician, Dr....
developed the Analgizer, a disposable inhaler that allowed the self-administration of methoxyflurane
Methoxyflurane
Methoxyflurane is a halogenated ether that was in clinical use as an volatile inhalational anesthetic from its introduction by Joseph F. Artusio et al in 1960 until around 1974. It was first synthesized in the late 1940s by William T...
vapor
Vapor
A vapor or vapour is a substance in the gas phase at a temperature lower than its critical point....
in air for analgesia. The Analgizer consisted of a polyethylene
Polyethylene
Polyethylene or polythene is the most widely used plastic, with an annual production of approximately 80 million metric tons...
cylinder 5 inches in length and 1 inch in diameter with a 1 inch long mouthpiece. The device contained a rolled wick
Candle wick
A candle wick is a string, cord, or wooden object that holds the flame of a candle. A candle wick works by capillary action, drawing the fuel to the flame. When the liquid fuel, typically melted candle wax, reaches the flame it then vaporizes and combusts. The candle wick influences how the...
of polypropylene
Polypropylene
Polypropylene , also known as polypropene, is a thermoplastic polymer used in a wide variety of applications including packaging, textiles , stationery, plastic parts and reusable containers of various types, laboratory equipment, loudspeakers, automotive components, and polymer banknotes...
felt
Felt
Felt is a non-woven cloth that is produced by matting, condensing and pressing woollen fibres. While some types of felt are very soft, some are tough enough to form construction materials. Felt can be of any colour, and made into any shape or size....
which held 15 milliliters of methoxyflurane. Because of the simplicity of the Analgizer and the pharmacological
Pharmacology
Pharmacology is the branch of medicine and biology concerned with the study of drug action. More specifically, it is the study of the interactions that occur between a living organism and chemicals that affect normal or abnormal biochemical function...
characteristics of methoxyflurane, it was easy for patients to self-administer the drug and rapidly achieve a level of conscious analgesia which could be maintained and adjusted as necessary over a period of time lasting from a few minutes to several hours. The 15 milliliter supply of methoxyflurane would typically last for two to three hours, during which time the user would often be partly amnesic
Amnesia
Amnesia is a condition in which one's memory is lost. The causes of amnesia have traditionally been divided into categories. Memory appears to be stored in several parts of the limbic system of the brain, and any condition that interferes with the function of this system can cause amnesia...
to the sense of pain; the device could be refilled if necessary. The Analgizer was found to be safe, effective, and simple to administer in obstetric
Obstetrics
Obstetrics is the medical specialty dealing with the care of all women's reproductive tracts and their children during pregnancy , childbirth and the postnatal period...
patients during childbirth, as well as for patients with bone fracture
Bone fracture
A bone fracture is a medical condition in which there is a break in the continuity of the bone...
s and joint dislocations, and for dressing changes on burn
Burn
A burn is an injury to flesh caused by heat, electricity, chemicals, light, radiation, or friction.Burn may also refer to:*Combustion*Burn , type of watercourses so named in Scotland and north-eastern England...
patients. When used for labor analgesia, the Analgizer allows labor to progress normally and with no apparent adverse effect
Adverse effect
In medicine, an adverse effect is a harmful and undesired effect resulting from a medication or other intervention such as surgery.An adverse effect may be termed a "side effect", when judged to be secondary to a main or therapeutic effect. If it results from an unsuitable or incorrect dosage or...
on Apgar score
Apgar score
The Apgar score was devised in 1952 by the eponymous Dr. Virginia Apgar as a simple and repeatable method to quickly and summarily assess the health of newborn children immediately after birth...
s. All vital signs
Vital signs
Vital signs are measures of various physiological statistics, often taken by health professionals, in order to assess the most basic body functions. Vital signs are an essential part of a case presentation. The act of taking vital signs normally entails recording body temperature, pulse rate ,...
remain normal in obstetric patients, newborns, and injured patients. The Analgizer was widely utilized for analgesia and sedation
Sedation
Sedation is the reduction of irritability or agitation by administration of sedative drugs, generally to facilitate a medical procedure or diagnostic procedure...
until the early 1970s, in a manner that foreshadowed the patient-controlled analgesia
Patient-controlled analgesia
Patient-controlled analgesia is any method of allowing a person in pain to administer their own pain relief. The infusion is programmable by the prescriber...
infusion pump
Infusion pump
An infusion pump infuses fluids, medication or nutrients into a patient's circulatory system. It is generally used intravenously, although subcutaneous, arterial and epidural infusions are occasionally used....
s of today. The Analgizer inhaler was withdrawn in 1974, but use of methoxyflurane as a sedative and analgesic continues in Australia and New Zealand in the form of the Penthrox inhaler
Penthrox inhaler
The Penthrox inhaler, manufactured and marketed by Medical Developments International , is a hand-held inhaler device which can be used for the self-administration of methoxyflurane for analgesia .-Indications:...
.
Propellants
In 2009, the FDA banned the use of inhalers that utilize chlorofluorocarbons (CFC) as propellants for hydrofluorocarbons (HFA) inhalers; HFA is not environmentally inert as a greenhouse gasGreenhouse gas
A greenhouse gas is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. The primary greenhouse gases in the Earth's atmosphere are water vapor, carbon dioxide, methane, nitrous oxide, and ozone...
but does not affect the ozone layer. While some asthma sufferers and advocacy groups contend that the latter are not as effective, published clinical studies indicate equivalent control of asthma is achieved with use of HFA inhalers. Inhalers used to treat asthma contains dry powder spin inhalers and aerosoles containing suspending liquid medicament, but in both the cases the size of suspended particles or powder particles must be less than 5 micrometres so as to increase the surface area and deliver the drug to the inner most areas. Such a sufficiently small size of particles is necessary for dispersion and also for rapid action.
While the impact of CFC of inhalers on the ozone layer
Ozone layer
The ozone layer is a layer in Earth's atmosphere which contains relatively high concentrations of ozone . This layer absorbs 97–99% of the Sun's high frequency ultraviolet light, which is potentially damaging to the life forms on Earth...
had been miniscule, the FDA in its interpretation of the Montreal Protocol
Montreal Protocol
The Montreal Protocol on Substances That Deplete the Ozone Layer is an international treaty designed to protect the ozone layer by phasing out the production of numerous substances believed to be responsible for ozone depletion...
mandated the switch in propellants. Patients expressed concern about the high price of the HFA inhalers as there is no generic version, which had been available in the CFC inhalers for many years. The elimination of generics from the market led to a price increase in inhalers that is expected to cost American consumers, insurances and the government about $8 billion by 2017.
Manufacturers
The largest manufacturers of inhalers are GlaxoSmithKlineGlaxoSmithKline
GlaxoSmithKline plc is a global pharmaceutical, biologics, vaccines and consumer healthcare company headquartered in London, United Kingdom...
(makers of the Advair Discus (a DPI), Merck
Merck & Co.
Merck & Co., Inc. , also known as Merck Sharp & Dohme or MSD outside the United States and Canada, is one of the largest pharmaceutical companies in the world. The Merck headquarters is located in Whitehouse Station, New Jersey, an unincorporated area in Readington Township...
, AstraZeneca
AstraZeneca
AstraZeneca plc is a global pharmaceutical and biologics company headquartered in London, United Kingdom. It is the world's seventh-largest pharmaceutical company measured by revenues and has operations in over 100 countries...
(makers of Pulmicort and Symbicort) and Boehringer-Ingelheim
Boehringer-Ingelheim
C.H. Boehringer Sohn AG & Ko. KG is the parent company of Boehringer Ingelheim, which was founded in 1885 by Albert Boehringer in Ingelheim am Rhein. The Boehringer Ingelheim group is one of the world's 20 leading pharmaceutical companies. Headquartered in Ingelheim, Germany, it operates globally...
(makers of Atrovent, Combivent, and Spiriva). BI, GSK, Merck, and AstraZeneca manufacture the medication being delivered via inhaler. However, 3M
3M
3M Company , formerly known as the Minnesota Mining and Manufacturing Company, is an American multinational conglomerate corporation based in Maplewood, Minnesota, United States....
Drug Delivery Systems does some of the finished product manufacturing, as they are one of the leaders of MDI canisters, metering valves and other components.
Further reading
- Patton, J., Breathing life into protein drugs - Inhalation of therapeutic macromolecules is a feasible, natural, more people-friendly, delivery system. Nature Biotechnology, 1998. 16(2): p. 141-143.
External links
- Basics aspects of inhaled pharmaceutical aerosols
- Recent advances in spray medication technology
- Ourasthma.com – a patient-oriented site with information on asthma inhalers.
- Discrete simulation of powder dispersion in pharmaceutical aerosol inhalers