Synthetic oxytocin, sold under the brand name Pitocin among others, is a

medication A medication (also called medicament, medicine, pharmaceutical drug, medicinal drug or simply drug) is a drug used to diagnose, cure, treat, or prevent disease. Drug therapy ( pharmacotherapy) is an important part of the medical field and ...

made Made or MADE may refer to: Entertainment Film * ''Made'' (1972 film), United Kingdom * ''Made'' (2001 film), United States Music * ''Made'' (Big Bang album), 2016 * ''Made'' (Hawk Nelson album), 2013 * ''Made'' (Scarface album), 2007 *'' M.A.D.E. ...

from the

peptide Peptides (, ) are short chains of amino acids linked by peptide bonds. Long chains of amino acids are called proteins. Chains of fewer than twenty amino acids are called oligopeptides, and include dipeptides, tripeptides, and tetrapeptides. ...

'' oxytocin''. As a medication, it is used to cause contraction of the

uterus The uterus (from Latin ''uterus'', plural ''uteri'') or womb () is the organ in the reproductive system of most female mammals, including humans that accommodates the embryonic and fetal development of one or more embryos until birth. The ...

to start labor, increase the speed of labor, and to stop bleeding following delivery. For this purpose, it is given by injection either into a muscle or into a vein. Oxytocin is also available in intranasal spray form for psychiatric, endocrine and weight management use as a supplement. Intranasal oxytocin works on a different pathway than injected oxytocin, primarily along the olfactory nerve crossing the brain blood barrier to the olfactory lobe in the brain, where dense magnocellular oxytocin neurons receive the dose application. The use of synthetic oxytocin as an injectable medication for inducing childbirth can result in excessive contraction of the uterus that can risk the health of the baby. Common

side effect In medicine, a side effect is an effect, whether therapeutic or adverse, that is secondary to the one intended; although the term is predominantly employed to describe adverse effects, it can also apply to beneficial, but unintended, consequence ...

s in the mother include nausea and a

slow heart rate Bradycardia (also sinus bradycardia) is a slow resting heart rate, commonly under 60 beats per minute (BPM) as determined by an electrocardiogram. It is considered to be a normal heart rate during sleep, in young and healthy or elderly adults, a ...

. Serious side effects include rupture of the uterus and with excessive dose,

water intoxication Water intoxication, also known as water poisoning, hyperhydration, overhydration, or water toxemia, is a potentially fatal disturbance in brain functions that results when the normal balance of electrolytes in the body is pushed outside safe li ...

Allergic reactions Allergies, also known as allergic diseases, refer a number of conditions caused by the hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic derm ...

including

anaphylaxis Anaphylaxis is a serious, potentially fatal allergic reaction and medical emergency that is rapid in onset and requires immediate medical attention regardless of use of emergency medication on site. It typically causes more than one of the foll ...

may also occur. The natural occurrence of oxytocin was discovered in 1906. It is on the

World Health Organization's List of Essential Medicines The WHO Model List of Essential Medicines (aka Essential Medicines List or EML), published by the World Health Organization (WHO), contains the medications considered to be most effective and safe to meet the most important needs in a health s ...

Medical uses

An intravenous infusion of oxytocin is used to induce labor and to support labor in case of slow childbirth if the oxytocin challenge test fails. Whether a high dose is better than a standard dose for labor induction is unclear. It has largely replaced

ergometrine Ergometrine, also known as ergonovine and sold under the brand names Ergotrate, Ergostat, and Syntometrine among others, is a medication used to cause contractions of the uterus to treat heavy vaginal bleeding after childbirth. It can be used ei ...

as the principal agent to increase uterine tone in acute

postpartum hemorrhage Postpartum bleeding or postpartum hemorrhage (PPH) is often defined as the loss of more than 500 ml or 1,000 ml of blood following childbirth. Some have added the requirement that there also be signs or symptoms of low blood volume fo ...

. Oxytocin is also used in

veterinary medicine Veterinary medicine is the branch of medicine that deals with the prevention, management, diagnosis, and treatment of disease, disorder, and injury in animals. Along with this, it deals with animal rearing, husbandry, breeding, research on nutri ...

to facilitate birth and to stimulate milk release. The

tocolytic Tocolytics (also called anti-contraction medications or labor suppressants) are medications used to suppress premature labor (from Greek τόκος ''tókos'', "childbirth", and λύσις ''lúsis'', "loosening"). Preterm birth accounts for 70% ...

agent

atosiban Atosiban, sold under the brand name Tractocile among others, is an inhibitor of the hormones oxytocin and vasopressin. It is used as an intravenous medication as a labour repressant (tocolytic) to halt premature labor. It was developed by Ferri ...

(Tractocile) acts as an antagonist of oxytocin receptors. It is registered in many countries for use in suppressing premature labor between 24 and 33 weeks of gestation. It has fewer side effects than drugs previously used for this purpose (such as

ritodrine Ritodrine (trade name Yutopar) is a tocolytic drug used to stop premature labor. This drug has been removed from the US market, according to FDA Orange Book. It was available in oral tablets or as an injection and was typically used as the hyd ...

, salbutamol and

terbutaline Terbutaline, sold under the brand names Bricanyl and Marex among others, is a β2 adrenergic receptor agonist, used as a "reliever" inhaler in the management of asthma symptoms and as a tocolytic (anti-contraction medication) to delay preterm ...

). Oxytocin has not been found to be useful for improving breastfeeding success.

Contraindications

Oxytocin injection (synthetic) is contraindicated in any of these conditions: * Substantial

cephalopelvic disproportion Cephalopelvic disproportion exists when the capacity of the pelvis is inadequate to allow the fetus to negotiate the birth canal. This may be due to a small pelvis, a nongynecoid pelvic formation, a large fetus, an unfavorable orientation of the f ...

* Unfavorable fetal position or presentation (e.g., transverse lies) undeliverable without conversion before delivery * Obstetric emergencies where maternal or fetal risk-to-benefit ratio favors surgery *

Fetal distress Fetal distress, also known as non-reassuring fetal status, is a condition during pregnancy or labor in which the fetus shows signs of inadequate oxygenation. Due to its imprecision, the term "fetal distress" has fallen out of use in American obstetr ...

when delivery is not imminent *

Umbilical cord prolapse Umbilical cord prolapse is when the umbilical cord comes out of the uterus with or before the presenting part of the baby. The concern with cord prolapse is that pressure on the cord from the baby will compromise blood flow to the baby. It usual ...

* Uterine activity fails to progress adequately * Hyperactive or hypertonic uterus * Vaginal delivery is contraindicated (e.g., invasive cervical carcinoma, active

genital herpes Genital herpes is an infection by the herpes simplex virus (HSV) of the genitals. Most people either have no or mild symptoms and thus do not know they are infected. When symptoms do occur, they typically include small blisters that break open ...

infection, total

placenta previa Placenta praevia is when the placenta attaches inside the uterus but in a position near or over the cervical opening. Symptoms include vaginal bleeding in the second half of pregnancy. The bleeding is bright red and tends not to be associated wi ...

vasa previa Vasa praevia is a condition in which fetal blood vessels cross or run near the internal opening of the uterus. These vessels are at risk of rupture when the supporting membranes rupture, as they are unsupported by the umbilical cord or placental ...

, cord presentation or prolapse) * Uterine or cervical scarring from previous

cesarean section Caesarean section, also known as C-section or caesarean delivery, is the surgical procedure by which one or more babies are delivered through an incision in the mother's abdomen, often performed because vaginal delivery would put the baby or ...

or major cervical or uterine (e.g., transfundal) surgery * Unengaged fetal head * History of

hypersensitivity Hypersensitivity (also called hypersensitivity reaction or intolerance) refers to undesirable reactions produced by the normal immune system, including allergies and autoimmunity. They are usually referred to as an over-reaction of the immune ...

to oxytocin or any ingredient in the formulation

Side effects

Oxytocin is relatively safe when used at recommended doses, and side effects are uncommon. These maternal

events Event may refer to: Gatherings of people * Ceremony, an event of ritual significance, performed on a special occasion * Convention (meeting), a gathering of individuals engaged in some common interest * Event management, the organization of ev ...

have been reported: * Subarachnoid hemorrhage *

Increased blood pressure Hypertension (HTN or HT), also known as high blood pressure (HBP), 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. Long-term high bl ...

Cardiac arrhythmia Arrhythmias, also known as cardiac arrhythmias, heart arrhythmias, or dysrhythmias, are irregularities in the heartbeat, including when it is too fast or too slow. A resting heart rate that is too fast – above 100 beats per minute in adults ...

including increased or decreased

heart rate Heart rate (or pulse rate) is the frequency of the heartbeat measured by the number of contractions (beats) of the heart per minute (bpm). The heart rate can vary according to the body's physical needs, including the need to absorb oxygen and excr ...

, and premature ventricular contraction * Impaired

uterine The uterus (from Latin ''uterus'', plural ''uteri'') or womb () is the organ in the reproductive system of most female mammals, including humans that accommodates the embryonic and fetal development of one or more embryos until birth. The ...

blood flow * Pelvic hematoma *

Afibrinogenemia Congenital afibrinogenemia is a rare, genetically inherited blood fibrinogen disorder in which the blood does not clot normally due to the lack of fibrinogen, a blood protein necessary for coagulation. This disorder is autosomal recessive, meanin ...

Anaphylaxis Anaphylaxis is a serious, potentially fatal allergic reaction and medical emergency that is rapid in onset and requires immediate medical attention regardless of use of emergency medication on site. It typically causes more than one of the foll ...

Nausea Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. While not painful, it can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the ...

and

vomiting Vomiting (also known as emesis and throwing up) is the involuntary, forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose. Vomiting can be the result of ailments like food poisoning, gastroenteri ...

* Increase fetal blood flow Excessive dosage or long-term administration (over a period of 24 hours or longer) has been known to result in tetanic uterine contractions,

uterine rupture Uterine rupture is when the muscular wall of the uterus tears during pregnancy or childbirth. Symptoms, while classically including increased pain, vaginal bleeding, or a change in contractions, are not always present. Disability or death of the ...

, postpartum hemorrhage, and

, sometimes fatal. Oxytocin was added to the Institute for Safe Medication Practices's list of High Alert Medications in Acute Care Settings in 2012. The list includes medications that have a high risk for harm if administered incorrectly. During pregnancy, increased uterine motility has led to decreased heart rate, cardiac arrhythmia, seizures, brain damage, and

death Death is the irreversible cessation of all biological functions that sustain an organism. For organisms with a brain, death can also be defined as the irreversible cessation of functioning of the whole brain, including brainstem, and brain ...

in the

fetus A fetus or foetus (; plural fetuses, feti, foetuses, or foeti) is the unborn offspring that develops from an animal embryo. Following embryonic development the fetal stage of development takes place. In human prenatal development, fetal dev ...

neonate An infant or baby is the very young offspring of human beings. ''Infant'' (from the Latin word ''infans'', meaning 'unable to speak' or 'speechless') is a formal or specialised synonym for the common term ''baby''. The terms may also be used to ...

. Use is linked to an increased risk of

postpartum depression Postpartum depression (PPD), also called postnatal depression, is a type of mood disorder associated with childbirth, which can affect both sexes. Symptoms may include extreme sadness, low energy, anxiety, crying episodes, irritability, and cha ...

in the mother. Certain learning and memory functions are impaired by centrally administered oxytocin. Also, systemic oxytocin administration can impair memory retrieval in certain aversive memory tasks. However, oxytocin does seem to facilitate learning and memory specifically for social information. Healthy males administered intranasal oxytocin show improved memory for human faces, in particular happy faces.

Pharmacokinetics

Routes of administration

One IU of oxytocin is the equivalent of about 2 μg or mcg of pure peptide. *

Injection Injection or injected may refer to: Science and technology * Injective function, a mathematical function mapping distinct arguments to distinct values * Injection (medicine), insertion of liquid into the body with a syringe * Injection, in broadca ...

: Clinical doses of oxytocin are given by injection either into a muscle or into a vein to cause contraction of the uterus. Very small amounts (< 1%) do appear to enter the

central nervous system The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain and spinal cord. The CNS is so named because the brain integrates the received information and coordinates and influences the activity of all p ...

in humans when peripherally administered. The compound has a

half-life Half-life (symbol ) is the time required for a quantity (of substance) to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable at ...

of typically about 3 minutes in the blood when given

intravenously Intravenous therapy (abbreviated as IV therapy) is a medical technique that administers fluids, medications and nutrients directly into a person's vein. The intravenous route of administration is commonly used for rehydration or to provide nutrie ...

. Intravenous administration requires 40 minutes to reach a steady-state concentration and achieve maximum uterine contraction response. * Buccal: Oxytocin was delivered in buccal tablets, but this is not common practice any more. * Under the tongue: Oxytocin is poorly absorbed

sublingually Sublingual (abbreviated SL), from the Latin for "under the tongue", refers to the pharmacological route of administration by which substances diffuse into the blood through tissues under the tongue. The sublingual glands receive their primary ...

. *

Nasal administration Nasal administration, popularly known as snorting, is a route of administration in which drugs are insufflated through the nose. It can be a form of either topical administration or systemic administration, as the drugs thus locally delivered c ...

: Oxytocin is effectively

distributed Distribution may refer to: Mathematics *Distribution (mathematics), generalized functions used to formulate solutions of partial differential equations *Probability distribution, the probability of a particular value or value range of a varia ...

to the brain when administered intranasally via a

nasal spray Nasal sprays are used to deliver medications locally in the nasal cavities or systemically. They are used locally for conditions such as nasal congestion and allergic rhinitis. In some situations, the nasal delivery route is preferred for syst ...

, after which it reliably crosses the blood–brain barrier and exhibits psychoactive effects in humans. No serious adverse effects with short-term application of oxytocin with 18~40 IU (36–80 mcg) have been recorded. Intranasal oxytocin has a central duration of at least 2.25 hours and as long as 4 hours. * Oral: Oxytocin is destroyed in the gastrointestinal tract, so it is not active orally.

History

Oxytocin's uterine-contracting properties were discovered by British pharmacologist

Henry Hallett Dale Sir Henry Hallett Dale (9 June 1875 – 23 July 1968) was an English pharmacologist and physiologist. For his study of acetylcholine as agent in the chemical transmission of nerve pulses (neurotransmission) he shared the 1936 Nobel Prize in Ph ...

in 1906. Oxytocin's milk ejection property was described by Ott and Scott in 1910 and by Schafer and Mackenzie in 1911. Oxytocin was the first polypeptide hormone to be sequenced or synthesized. Du Vigneaud was awarded the Nobel Prize in 1955 for his work.

Etymology

The word ''oxytocin'' was coined from the term ''oxytocic''.

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

ὀξύς, ''oxys'', and τόκος, ''tokos'', meaning "quick birth".

Society and culture

Counterfeits

In African countries, some oxytocin products were found to be

counterfeit medications A counterfeit medication or a counterfeit drug is a medication or pharmaceutical item which is produced and sold with the intent to deceptively represent its origin, authenticity, or effectiveness. A counterfeit drug may contain inappropriate qu ...

Other uses

The trust-inducing property of oxytocin might help those with

social anxiety Social anxiety is the anxiety and fear specifically linked to being in social settings (i.e., interacting with others). Some categories of disorders associated with social anxiety include anxiety disorders, mood disorders, autism spectrum disor ...

and depression, anxiety, fear, and social dysfunctions, such as generalized anxiety disorder, post-traumatic stress disorder, and social anxiety disorder, as well as autism and schizophrenia, among others. However, in one meta-analysis only

autism spectrum disorder The autism spectrum, often referred to as just autism or in the context of a professional diagnosis autism spectrum disorder (ASD) or autism spectrum condition (ASC), is a neurodevelopmental condition (or conditions) characterized by difficulti ...

showed a significant combined effect size. People using oxytocin show improved recognition for positive

social cue Social cues are verbal or non-verbal signals expressed through the face, body, voice, motion (and more) and guide conversations as well as other social interactions by influencing our impressions of and responses to others. These percepts are impo ...

s over threatening social cues and improved recognition of fear. * Autism: Oxytocin may play a role in autism and may be an effective treatment for autism's repetitive and affiliative behaviors. *

Relationship counseling Couples therapy (also couples' counseling, marriage counseling, or marriage therapy) attempts to improve romantic relationships and resolve interpersonal conflicts. History Marriage counseling originated in Germany in the 1920s as part of the eu ...

: The use of oxytocin in relationship counseling for well-being has been suggested.

References

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