INN
Inns are generally establishments or buildings where travelers can seek lodging, and usually, food and drink. Inns are typically located in the country or along a highway. Before the advent of motorized transportation, they also provided accomm ...
), also known as tetrahydrozoline, is a drug used in some over-the-counter
eye drop
Eye drops or eyedrops are liquid drops applied directly to the surface of the eye usually in small amounts such as a single drop or a few drops. Eye drops usually contain saline to match the salinity of the eye. Drops containing only saline ...
s and
nasal spray
Nasal sprays are used to deliver medications Route of administration#Local, locally in the nasal cavities or systemic administration, systemically. They are used locally for conditions such as nasal congestion and allergic rhinitis. In some sit ...
s. Tetryzoline was patented in 1954, and came into medical use in 1959.
Side effects
Tetryzoline eye drops may cause blurred vision, eye irritation and
dilated pupils
Mydriasis is the dilation of the pupil, usually having a non-physiological cause, or sometimes a physiological pupillary response. Non-physiological causes of mydriasis include disease, trauma, or the use of certain types of drugs. It may also b ...
. Tetryzoline is not suitable for prolonged use as its vasoconstrictive effects within the eye eventually decrease or stop. If tolerance to the drug has developed, ceasing its use may cause a rebound effect and ''increase'' redness of the eyes — a vasodilatory effect.
Intranasal use of tetryzoline may cause transient burning, stinging, or dryness of the
mucosa
A mucous membrane or mucosa is a membrane that lines various cavities in the body of an organism and covers the surface of internal organs. It consists of one or more layers of epithelial cells overlying a layer of loose connective tissue. It ...
and sneezing. Prolonged intranasal use often causes opposite effects in the form of
rebound congestion
Rhinitis medicamentosa (or RM, also known as rebound congestion) is a condition of rebound nasal congestion suspected to be brought on by extended use of topical decongestants (e.g., oxymetazoline, phenylephrine, xylometazoline, and naphazoline n ...
with effects such as chronic redness, swelling and
rhinitis
Rhinitis, also known as coryza, is irritation and inflammation of the mucous membrane inside the nose. Common symptoms are a stuffy nose, runny nose, sneezing, and post-nasal drip.
The inflammation is caused by viruses, bacteria, irritant ...
. Prolonged use thus may result in overuse of the drug.
In children, it might cause profound sedation.
Overdose
Overdose most often causes
slow heart rate
Bradycardia, also called bradyarrhythmia, is a resting heart rate under 60 beats per minute (BPM). While bradycardia can result from various pathological processes, it is commonly a physiological response to cardiovascular conditioning or due t ...
.
Respiratory depression
Hypoventilation (also known as respiratory depression) occurs when ventilation is inadequate (''hypo'' meaning "below") to perform needed respiratory gas exchange. By definition it causes an increased concentration of carbon dioxide (hypercapni ...
,
low blood pressure
Hypotension, also known as low blood pressure, is a cardiovascular condition characterized by abnormally reduced blood pressure. Blood pressure is the force of blood pushing against the walls of the arteries as the heart pumps out blood and is ...
hypothermia
Hypothermia is defined as a body core temperature below in humans. Symptoms depend on the temperature. In mild hypothermia, there is shivering and mental confusion. In moderate hypothermia, shivering stops and confusion increases. In severe ...
, brief episodes of
high blood pressure
Hypertension, also known as high blood pressure, is a long-term medical condition in which the blood pressure in the arteries is persistently elevated. High blood pressure usually does not cause symptoms itself. It is, however, a major ri ...
, drowsiness, headaches and vomiting may also occur. In serious cases some of these effects may result in
circulatory shock
Shock is the state of insufficient blood flow to the tissues of the body as a result of problems with the circulatory system. Initial symptoms of shock may include weakness, tachycardia, hyperventilation, sweating, anxiety, and increased thirst. ...
. Most often overdoses occur in children who have ingested the drug.
There is no antidote for tetryzoline or other similar imidazoline analogue poisoning, but the symptoms can be alleviated. With treatment, death is rare.
alpha-1 Alpha 1 or Alpha-1 may refer to:
*Alpha-1 adrenergic receptor, a G protein-coupled receptor
*Alpha-1 antitrypsin, a protein
**Alpha-1 antitrypsin deficiency, a genetic disorder
*Alpha-1-fetoprotein or Alpha-fetoprotein, a protein
*Alpha-One, a fict ...
and alpha-2 receptors. This action relieves the redness of the eye caused by minor ocular irritants. Moreover, to treat
allergic conjunctivitis
Allergic conjunctivitis (AC) is Allergic Inflammation, inflammation of the conjunctiva (the membrane covering the white part of the eye) due to allergy. Although allergens differ among patients, the most common cause is hay fever. Symptoms consist ...
, tetryzoline can be combined in a solution with antazoline.
Pharmacokinetics
In a healthy person, the
biological half-life
Biological half-life (elimination half-life, pharmacological half-life) is the time taken for concentration of a drug, biological substance (such as a medication) to decrease from its maximum concentration (chemistry), concentration (Cmax (pharm ...
of tetryzoline is approximately 6 hours, and it is excreted in urine, chemically unchanged, at least in part. In one study, 10 people were given two drops of 0.5 mg/mL of tetryzoline eye drops (0.025–0.05 mg) at 0 hrs, 4 hrs, 8 hrs, and 12 hrs. Within a 24-hour time window, since the last dose of tetryzoline, the blood serum concentration of tetryzoline in the test subjects was 0.068-0.380 ng/mL and the urine concentration was 13–210 ng/mL. Both the blood and the urine levels of tetryzoline reached their maximums approximately 9 hrs after the last dose. These fluid-concentration levels correspond to normal ocular use of tetryzoline; thus, greater concentrations of tetryzoline in the blood and the urine of the user can indicate misuse of the drug or of poisoning with the drug.
Chemistry
Chemically, tetryzoline is a
derivative
In mathematics, the derivative is a fundamental tool that quantifies the sensitivity to change of a function's output with respect to its input. The derivative of a function of a single variable at a chosen input value, when it exists, is t ...
of
imidazoline
Imidazoline is a heterocycle formally derived from imidazole by the reduction of one of the two double bonds. Three isomers are known, 2-imidazolines, 3-imidazolines, and 4-imidazolines. The 2- and 3-imidazolines contain an imine center, whereas t ...
. It has two
enantiomers
In chemistry, an enantiomer (Help:IPA/English, /ɪˈnænti.əmər, ɛ-, -oʊ-/ Help:Pronunciation respelling key, ''ih-NAN-tee-ə-mər''), also known as an optical isomer, antipode, or optical antipode, is one of a pair of molecular entities whi ...
.
Society and culture
Names
Tetryzoline is the International Nonproprietary Name (INN).
Urban legend
An
urban legend
Urban legend (sometimes modern legend, urban myth, or simply legend) is a genre of folklore concerning stories about an unusual (usually scary) or humorous event that many people believe to be true but largely are not.
These legends can be e ...
suggests that tetryzoline can cause violent diarrhea if given orally, such as by putting a few drops of
Visine
Visine (), also known as Vispring, is a brand of eye drops produced by Kenvue. Visine was first introduced in 1958 and was acquired by Pfizer in 1999. In 2006, Johnson & Johnson acquired Visine, along with Pfizer's entire consumer healthcare por ...
in an unsuspecting person's beverage. However, the actual results of the prank may be worse, varying from severe nausea and vomiting to seizures or a coma. Larger doses can cause death. Diarrhea is not a side effect.
Criminal use
In late August 2018, a
South Carolina
South Carolina ( ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders North Carolina to the north and northeast, the Atlantic Ocean to the southeast, and Georgia (U.S. state), Georg ...
woman was charged with murdering her husband by putting eye drops containing tetryzoline in his drinking water. An autopsy found a high concentration of tetryzoline in his body.
Tetryzoline has been used as a
date rape drug
A date rape drug is any drug that incapacitates another person and renders that person vulnerable to sexual assault, including rape. These substances are associated with date rape because of reported incidents of their use in the context of two ...
in a number of cases due to its ability to cause dizziness and unconsciousness.
In 2018, a 62 year-old woman in
Pewaukee, Wisconsin
Pewaukee is a city in Waukesha County, Wisconsin, United States. The population was 15,914 at the 2020 census. It is part of the Milwaukee metropolitan area.
The name of the city of Pewaukee comes from that of the name of the village, the ori ...
, died in an apparent overdose or suicide involving tetryzoline and other substances; in November 2023 her caregiver was convicted of
first-degree murder
Murder is the unlawful killing of another human without justification or valid excuse committed with the necessary intention as defined by the law in a specific jurisdiction. ("The killing of another person without justification or excuse ...
, following the allegation that her death was caused by a water bottle laced with
Visine
Visine (), also known as Vispring, is a brand of eye drops produced by Kenvue. Visine was first introduced in 1958 and was acquired by Pfizer in 1999. In 2006, Johnson & Johnson acquired Visine, along with Pfizer's entire consumer healthcare por ...
.
In 2019, a
North Carolina
North Carolina ( ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It is bordered by Virginia to the north, the Atlantic Ocean to the east, South Carolina to the south, Georgia (U.S. stat ...
paramedic was accused of using tetryzoline eye drops to cause the death of his wife. The blood sample results showed about 30–40 times higher than the therapeutic level of tetryzoline.
Use in Media
In the
9-1-1
911, sometimes written , is an emergency telephone number for Argentina, Canada, the Dominican Republic, Fiji, Jordan, Mexico, Pakistan, Maldives, Palau, Panama, Iraq, the Philippines, Sint Maarten, the United States, and Uruguay, as well as ...
Season 4 Episode 13 ''Suspicion'', a mother, Sheila, poisons her son, Charlie, with tetryzoline eye drops by putting it into his food to make him seem sick and gain donations as a form of
Munchausen syndrome by proxy
Factitious disorder imposed on another (FDIA), also known as fabricated or induced illness by carers (FII), medical child abuse and originally named Munchausen syndrome by proxy (MSbP) after Munchausen syndrome, is a mental health disorder in ...
. Charlie later poisons Sheila the same way with the same medication.