Naloxone is a medicinal agent that is attributed to the opiod agonist group, meaning that it does not have opioid-like effects itself. Naloxone is used to reverse the effects of opioids as an antidote. It is administered intramuscularly, subcutaneously, or intravenously.
What is naloxone?
The substance naloxone is one of the opioid antagonists. Together with the closely related substance naltrexone, naloxone forms the subgroup of competitive antagonists. These act at all opioid receptors without themselves exerting the (mildly sedating) effect typical of opioids. This enables naloxone to counteract the effects of opioids. The drug is therefore also known as an antidote and is used primarily in opioid overdoses. An antidote is a substance that inactivates a poison and thus reduces or cancels its effect (“antidote”). In pharmacology and chemistry, naloxone is described by the chemical molecular formula C 19 – H 21 – N – O 4. The moral mass of the whitish solid is 327.37 g/mol. In human medicine, naloxone is usually administered intravenously. However, in exceptional cases, administration by the subcutaneous or intramuscular route is also possible. Subcutaneous administration occurs when the active ingredient is injected under the skin. An intramuscular injection is when the active ingredient is injected directly into a skeletal muscle. Intravenous administration is when nalaxone is delivered directly through a syringe into a vein.
Pharmacologic Action
Naloxone binds to the same receptors that opiods bind to (opioid receptors) but does not exert opioid effects there. For this reason, opioids (e.g., opium, heroin, or methadone) are prevented from docking at the receptors. These substances now show no effect. Naloxone, however, only has a competitive effect. It follows that there must always be a sufficiently large quantity of the active substance in the blood to be able to keep the opioids permanently away from the receptors. Particularly in situations where an opioid overdose is to be treated, a particularly high dose of naloxone is therefore administered. Unlike opioids, however, naloxone does not cause dependence or other abnormalities. This is true both physically and psychologically. It is therefore also added to some opioid painkillers to prevent abuse or to make such abuse unattractive. Because naloxone is usually administered intravenously, an effect is achieved within seconds. The substance spreads rapidly through the bloodstream and thus penetrates the brain after only a short time. The duration of action of naloxone is between one and four hours. It is thus comparatively short, which can make repeated treatments necessary. The maximum daily dose is 24 mg. The short duration of action of naloxone is due to the fact that it is broken down by the liver and proceeds rapidly. Thus, half of the amount of active ingredient is already processed after only two hours. The substance is excreted through the urine.
Medical application and use
Naloxone is used as an antidote to treat opioid overdoses of any kind. It does not matter which drug caused the overdose. For example, heroin addicts who have overdosed themselves are also treated with naloxone to reverse the sedative effect of the drug and thus keep the patient alive. Naloxone is also used to treat respiratory depression caused by opiod analgesics (painkillers). Since the drug is most often used in emergency situations, it is administered intravenously. Naloxone is then injected directly into the vein through a syringe. In this way, successes can be recorded after only seconds. Naloxone can also be used preventively. For this purpose, it is added to some opioid-containing drugs (e.g., tilidine). The addition is intended to prevent abuse or make such abuse unattractive. This succeeds, since Tilidin (opiate) can develop an effect by the addition of Naloxon exclusively by oral ingestion. An addict will not experience intoxication from the abusive injection of the tilidine-naloxone gem.
Risks and side effects
Naloxone can cause unwanted side effects. The likelihood of this increases if the maximum daily dose is exceeded. Very often, patients experience an increase in blood pressure.Often there are also complaints of the gastrointestinal tract, which manifest themselves as nausea, diarrhea and vomiting. Especially in patients who have received naloxone due to an overdose of a painkiller, the pain-relieving effect may be reversed. The suppressed pain then revives. Opium-dependent people may also develop opiate withdrawal syndrome. In that case, there is a contraindication. Furthermore, it is possible that naloxone causes allergic reactions. So, if possible, it should be checked whether there is an intolerance. Studies have also shown that naloxone can cause skin reactions (especially itching or redness). Hyperventilation (extremely rapid inhalation) or convulsions may also occur. It is also possible that severe headaches may develop.
