While it has been shown that a single dose does not significantly alter either maternal or fetal circulation, this subject has not been studied extensively enough to draw reliable conclusions. Overdose
If accidentally ingested, standard methods to remove unabsorbed drugs should be considered. There is no specific antidote for oxymetazoline, although its pharmacological effects may be reversed by an adrenergic antagonists such as phentolamine. In the event of a possibly life-threatening overdose (such as a hypertensive crisis), benzodiazepines should be considered to decrease the likelihood of seizures and convulsions, as well as reduce anxiety and to lower blood pressure. In children, oxymetazoline may produce profound central nervous system depression due to stimulation of central α2 receptors and imidazoline receptors, much like clonidine. Pharmacology
Pharmacodynamics
Oxymetazoline is a sympathomimetic that selectively agonizes α1 and, partially, α2 adrenergic receptors. Since vascular beds widely express α1 receptors, the action of oxymetazoline results in vasoconstriction. In addition, the local application of the drug also results in vasoconstriction due to its action on endothelial postsynaptic α2 receptors; systemic application of α2 agonists, in contrast, causes vasodilation because of centrally-mediated inhibition of sympathetic tone via presynaptic α2 receptors. Vasoconstriction of vessels results in relief of nasal congestion in two ways: first, it increases the diameter of the airway lumen; second, it reduces fluid exudation from postcapillary venules. It can reduce nasal airway resistance (NAR) up to 35.7% and reduce nasal mucosal blood flow up to 50%.
Pharmacokinetics
Since imidazolines are sympathomimetic agents, their primary effects appear on α adrenergic receptors, with little if any effect on β adrenergic receptors. Like other imidazolines, Oxymetazoline is readily absorbed orally. Effects on α receptors from systemically absorbed oxymetazoline hydrochloride may persist for up to 7 hours after a single dose. The elimination half-life in humans is 5–8 hours. It is excreted unchanged both by the kidneys (30%) and in feces (10%). History
The oxymetazoline brand Afrin was first sold as a prescription medication in 1966. After finding substantial early success as a prescription medication, it became available as an over-the-counter drug in 1975. Schering-Plough did not engage in heavy advertising until 1986.From the mid-1980s to mid-1990s, the brand Sinex was featured in many television advertisements. Some of these commercials showed men, women, and children using other brands of nasal sprays, and then standing upside down on a sidewalk, or against a wall, etc. or hanging upside down from various playground equipment to prevent their nasal spray from dripping out. This was juxtaposed with Sinex users not having to hang upside side down or stand on their heads as it didnt drip out. Brand names
Brand names include Afrin, Drixine, Dristan, Nasivin, Nasivion, Nezeril, Nostrilla, Logicin, Vicks Sinex, Visine L.R., Sudafed OM, Zicam, Otrivin Oxy, SinuFrin, Upneeq, and Mucinex Sinus-Max. == References ==