Afrin Cream

Oxymetazoline is an imidazole derivative and a potent, direct-acting alpha (α)-adrenergic agonist with affinity to both α₁- and α₂-adrenoceptors. Oxymetazoline is available in various formulations with a wide variety of clinical implications. The topical formulation of the drug is used to treat persistent facial redness in adults. As an effective decongestant, oxymetazoline is available in over-the-counter intranasal sprays used to relieve nasal and sinus congestion caused by a wide variety of conditions, such as common cold, hay fever, and upper respiratory allergies. In dentistry, oxymetazoline and tetracaine combination intranasal spray (Kovanaze) is used for regional anesthesia during dental procedures in children and adults. In July 2020, the FDA approved the use of an ophthalmic formulation of oxymetazoline (Upneeq) in adults with acquired blepharoptosis, or ptosis, making it the first FDA-approved medical treatment for this medical condition.

Oxymetazoline is an alpha-1A adrenoceptor agonist used to treat nasal congestion, allergic reactions of the eye, and facial erythema associated with rosacea.

Oxymetazoline is indicated for the topical treatment of persistent facial erythema associated with rosacea in adults.

Ophthalmic oxymetazoline is indicated for the treatment of acquired blepharoptosis in adults.

When used in combination with tetracaine intranasally, oxymetazoline is indicated for regional anesthesia when performing a restorative procedure on Teeth 4-13 and A-J in adults and children who weigh 40 kg or more.

Oxymetazoline can be found in over-the-counter nasal products as a nasal decongestant.

For off-label uses, oxymetazoline has been used during nasal intubation and during ear, nose, and throat surgery to improve visualization of the airway and to minimize post-operative bleeding.

• Acquired Blepharoptosis
• Allergic Rhinitis (AR)
• Nasal Congestion
• Postoperative Hemorrhages
• Rhinorrhoea
• Sinus Congestion
• Acute Rhinitis
• Persistent facial erythema
• Airway visualization

Oxymetazoline is an adrenergic α₁- and α₂-agonist and a direct-acting sympathomimetic drug. By stimulating adrenergic receptors, oxymetazoline causes vasoconstriction of dilated arterioles and reduces blood flow. In a radioligand competition study, oxymetazoline displayed higher affinity at α_1A-adrenoceptors compared to α_2B-adrenoceptors, but with higher potency at α_2B-adrenoceptors. When sprayed intranasally, oxymetazoline relieved relief nasal congestion and improved nasal airflow in patients with acute coryzal rhinitis for up to 12 hours following a single dose.

An early in vitro study demonstrated oxymetazoline to exert anti-oxidant actions, where it inhibited microsomal lipid peroxidation and mediated hydroxyl radical scavenging activity. This suggests that oxymetazoline has a beneficial effect against oxidants, which play a role in tissue damage in inflammation.

Oxymetazoline binds to α₁- and α₂-adrenoceptors, which are Gq-protein-coupled receptors that promote vascular smooth muscle contraction by increasing intracellular calcium levels in response to ligand activation.

Rosacea is a condition characterized by transient and persistent facial erythema. By stimulating α_1A-adrenoceptors and causing vasoconstriction, oxymetazoline is believed to diminish the symptoms of erythema. In blepharoptosis, it is hypothesized that oxymetazoline works by stimulating α-adrenergic receptors on the Müller muscle that elevates the upper eyelid, causing muscle contraction. Oxymetazoline is used in combination with tetracaine for local anesthesia in dentistry. Such combination use adds beneficial effects: the vasoconstrictor counteracts the local anesthetic agent's vasodilatory action, thereby constricting dilated arterioles and reducing blood flow to the application area. Oxymetazoline relieves nasal congestion by vasoconstricting the respiratory microvasculature, in both resistance and capacitance blood vessels on the human nasal mucosa, leading to decreased nasal mucosal blood flow, edema, and airflow resistance.

Imidazole derivatives such as oxymetazoline are readily absorbed across mucosal membranes, especially in children. In adult subjects with erythema associated with rosacea, the mean ± standard deviation (SD) C_max was 60.5 ± 53.9 pg/mL and the AUC from time 0 to 24 hours (AUC_0-24hr) was 895 ±798 pg x hr/mL following topical administration of first-dose oxymetazoline. Following once-daily topical applications for 28 days, the mean ± SD C_max was 66.4 ± 67.1 pg/mL and the AUC_0-24hr was 1050 ± 992 pg x hr/mL. Following twice-daily applications for 28 days, the mean ± SD C_max was 68.8 ± 61.1 pg/mL and the AUC_0-24hr was 1530 ± 922 pg x hr/mL.

Following single-drop ocular administration of oxymetazoline in healthy adult subjects, the mean ± SD C_max was 30.5 ± 12.7 pg/mL and the area under the concentration-time curve (AUC_inf) was 468 ± 214 pg x hr/mL. The median T_max was 2 hours, ranging from 0.5 to 12 hours.

Following nasal administration of an 0.6 mL combination product containing tetracaine and oxymetazoline in adult subjects, the maximum concentrations of oxymetazoline were reached within approximately 10 minutes. The mean C_max was 1.78 ng/mL and the AUC_0-inf value was 4.24 ng x h/mL, with a median Tmax of 5 minutes.

There is limited information on the volume of distribution of oxymetazoline.

In vitro, oxymetazoline is 56.7% to 57.5% bound to human plasma proteins.

While the excretion of oxymetazoline following nasal, topical, or ophthalmic administration of oxymetazoline has not been fully characterized in humans, it is believed that the predominant route of elimination at clinically relevant concentrations of oxymetazoline is renal excretion.

Following ocular administration in healthy adults, the mean terminal half-life was 8.3 hours, ranging from 5.6 to 13.9 hours.

The terminal half-life of oxymetazoline following nasal administration of the combination product containing tetracaine and oxymetazoline in adult subjects is approximately 5.2 hours.

There is limited information on the clearance rate of oxymetazoline.

In rats, the oral LD₅₀ is 680 ug/kg and the subcutaneous LD₅₀ is 1630 ug/kg. In mice, the oral LD₅₀ is 4700 ug/kg, the intraperitoneal LD₅₀ is 48 mg/kg, and the subcutaneous LD₅₀ is 34 mg/kg.

Case reports have documented unintended overdose in both children and adults: overdose has led to dizziness, chest pain, headaches, myocardial infarction, stroke, visual disturbances, arrhythmia, hypertension, or hypotension. Accidental ingestion of topical solutions of imidazoline derivatives, including oxymetazoline, in children has resulted in serious adverse events requiring hospitalization, such as nausea, vomiting, lethargy, tachycardia, decreased respiration, bradycardia, hypotension, hypertension, sedation, somnolence, mydriasis, stupor, hypothermia, drooling, and coma. Possible rebound nasal congestion, irritation of nasal mucosa, and adverse systemic effects (particularly in children), including serious cardiovascular adverse events, have been reported with overdosage as well as prolonged or too frequent intranasal use of oxymetazoline. Overdose should be responded with close monitoring, supportive care, and symptomatic treatment.

No interactions found.