Medical uses
Oxymetazoline is available over-the-counter as a topical decongestant in the form of oxymetazoline hydrochloride in nasal sprays such as Otrivin, Afrin, Operil, Dristan, Dimetapp, Oxyspray, Facimin, Nasivin, Nostrilla, Utabon, Sudafed OM, Vicks Sinex, Zicam, SinuFrin, Drixoral
and Mucinex Full Force.In the United States, oxymetazoline 1% cream is approved by the Food and Drug Administration for topical treatment of persistent facial erythema (redness) associated with rosacea in adults.Due to its vasoconstricting properties, oxymetazoline is also used to treat nose bleeds and eye redness due to minor irritation (marketed as Visine L.R. in the form of eye drops). In July 2020, oxymetazoline received approval by the FDA for the treatment of acquired drooping eyelid. Side effects
Rebound congestion
Rebound congestion, or rhinitis medicamentosa, may occur. A 2006 review of the pathology of rhinitis medicamentosa concluded that use of oxymetazoline for more than three days may result in rhinitis medicamentosa and recommended limiting use to three days. Australian regulatory submission
In a submission to the Therapeutic Goods Administration, a Novartis representative concluded, "The justification was not based on evidence." Citing an existing extensive body of evidence and noting a range of recommended periods from five to ten days, Novartis recommended the established five day period for its use for self-medication without medical consultation as it coincides with the typical duration of the common cold. Use in pregnancy
The Food and Drug Administration places oxymetazoline in category C, indicating risk to the fetus cannot be ruled out.
Fluoroquinolone antibiotics such as moxifloxacin, levofloxacin, and ciprofloxacin should also be avoided due to an increased serum concentration of tizanidine when administered concomitantly. Tizanidine has the potential to interact with other central nervous system depressants. Alcohol should be avoided, particularly as it can upset the stomach. The CNS-depressant effects of tizanidine and alcohol are additive. Caution with the following interactions:
antibiotics such as enoxacin, gatifloxacin, levofloxacin, lomefloxacin, moxifloxacin, ofloxacin, sparfloxacin, trovafloxacin, or norfloxacin;
blood pressure medications such as clonidine, guanabenz, guanfacine (Tenex), or methyldopa;
heart rhythm medications such as amiodarone (Cordarone, Pacerone), mexiletine (Mexitil), propafenone (Rhythmol), and verapamil (Calan, Covera, Isoptin). Pharmacology
Tizanidine is an α2 receptor agonist closely related to clonidine. It has  approximately one tenth to one fifteenth of the pressure lowering effect of clonidine. The relation between the α2 receptor agonism and the spasmolytic action is still not fully understood. Route of administration
Tizanidine is available as a tablet or capsule. Capsules may be opened and sprinkled on food. However, this may change the absorption of the medication compared to taking the capsule whole. Chemistry
It has a volume of distribution of 2.4 L/kg following intravenous administration. References
External links
"Tizanidine". Drug Information Portal. U.S. National Library of Medicine. "Tizanidine hydrochloride". Drug Information Portal. U.S. National Library of Medicine. "Tizanidine side effects". Drug Information Portal. tizanidine-side-effects.us.