Felypressin as Vasoconstrictor

Generic name: Felypressin

Alternative name: Octapressin

Category: Non-catecholamine vasoconstrictor; synthetic vasopressin analogue used with dental local anesthetics

Common dental combination: Prilocaine 3% with felypressin 0.03 IU/mL, also described in some labels as felypressin 0.54 micrograms/mL. Brand availability and cartridge size vary by country.

This article is for dental education only. Felypressin is usually encountered as part of prilocaine dental cartridges, not as a separate dental injection. Safe use requires checking the prilocaine dose, vasoconstrictor exposure, pregnancy status, cardiovascular history, methemoglobinemia risk, aspiration technique, and the patient’s medical condition.

Felypressin is a vasoconstrictor used in some dental local anesthetic solutions, most commonly with prilocaine 3%. It is not an adrenergic catecholamine like epinephrine.

Its main dental role is to slow local anesthetic absorption and prolong anesthesia while avoiding the typical beta-adrenergic effects of epinephrine, such as marked tachycardia or palpitations.

The key clinical limitation is that felypressin is not a universal replacement for epinephrine. It is weaker for hemostasis, is linked to pregnancy concerns, and is usually combined with prilocaine, which has its own methemoglobinemia risk.

• Best use: selected dental anesthesia when an adrenaline-free vasoconstrictor option is desired
• Common dental context: short to moderate restorative, periodontal, and extraction procedures using prilocaine with felypressin
• Main advantage: less direct beta-adrenergic stimulation than epinephrine-containing cartridges
• Main limitation: less powerful hemostasis and special caution in pregnancy
• Clinical priority: remember that the safety profile is mainly “prilocaine + felypressin,” not felypressin alone

• Dental local anesthesia with prilocaine when a non-adrenaline vasoconstrictor is preferred
• Infiltration anesthesia for selected restorative procedures
• Nerve blocks for dental treatment when product labeling and patient risk allow
• Periodontal procedures where moderate duration is useful
• Simple extractions or minor procedures when strong hemostasis is not the main requirement
• Alternative option in selected patients who experience strong epinephrine-related palpitations or tremor
• Situations where epinephrine should be minimized, but a plain anesthetic may not provide enough duration

Common dental formulation: Prilocaine hydrochloride 3% with felypressin 0.03 IU/mL, equivalent in some product labels to felypressin 0.54 micrograms/mL.

• 1.8 mL cartridge: about 54 mg prilocaine + 0.054 IU felypressin
• 2.2 mL cartridge: about 66 mg prilocaine + 0.066 IU felypressin

In practice, the limiting dose is usually the prilocaine dose, the patient’s medical status, and the clinical need. The dentist should not think only about the vasoconstrictor; the local anesthetic milligram dose is still essential.

Example only: Some prilocaine-with-felypressin product information lists a maximum dose based on prilocaine, such as about 8 mg/kg, with an adult maximum that may be expressed as up to 600 mg prilocaine depending on the local product label.

If one 1.8 mL cartridge contains about 54 mg prilocaine, 600 mg equals about 11 cartridges by prilocaine calculation. This is a mathematical ceiling, not a routine target.

The practical number is often lower because of age, weight, liver or kidney disease, cardiovascular disease, pregnancy, anemia, methemoglobinemia risk, oxidizing drugs, procedure length, injection site, and whether other local anesthetics were used.

• Pregnancy, especially when safer alternatives such as lidocaine with epinephrine are suitable, because felypressin has oxytocic/uterotonic concern
• Known hypersensitivity to prilocaine, amide local anesthetics, felypressin, or any product component
• Congenital or acquired methemoglobinemia, significant G6PD deficiency, or previous medication-induced methemoglobinemia
• Severe anemia, significant hypoxia, or serious cardiopulmonary disease where reduced oxygen delivery would be dangerous
• Severe liver or kidney disease requiring dose reduction or medical guidance
• Recent myocardial infarction, unstable angina, serious ischemic heart disease, or significant cardiovascular instability without medical guidance
• Use beyond maximum safe prilocaine dose or without ability to manage toxicity
• Unsafe injection technique or suspected intravascular injection
• Procedures needing strong hemostasis where epinephrine-containing solutions may be more effective if medically appropriate

• Pregnancy warning: felypressin is generally avoided because of concern for uterine contraction and reduced uteroplacental blood flow.
• Prilocaine warning: prilocaine can contribute to methemoglobinemia, especially in susceptible patients or with high doses.
• Methemoglobinemia signs: blue/gray skin, shortness of breath, fatigue, dizziness, low oxygen saturation that does not improve as expected with oxygen, or chocolate-brown blood.
• Local anesthetic systemic toxicity: can occur after overdose, rapid absorption, repeated dosing, or intravascular injection.
• Less hemostasis: felypressin is usually less effective for surgical bleeding control than epinephrine.
• Cardiovascular nuance: it has less direct beta-stimulation than epinephrine, but it is still a vasoconstrictor and should not be used casually in unstable cardiovascular disease.
• Do not ignore the anesthetic dose: even if the vasoconstrictor is not adrenaline, systemic local anesthetic toxicity remains possible.

The common mistake is to call felypressin “safe adrenaline-free anesthesia” and stop thinking. It is safer than epinephrine for some catecholamine-sensitive situations, but it comes with a prilocaine dose limit, methemoglobinemia risk, weaker hemostasis, and pregnancy warning.

• Other local anesthetics: total local anesthetic dose is additive and increases toxicity risk.
• Methemoglobinemia-associated drugs: dapsone, nitrates, nitrites, sulfonamides, phenazopyridine, nitrofurantoin, antimalarials, benzocaine, and other oxidizing agents may increase risk when used with prilocaine.
• Class I antiarrhythmic drugs: may have additive cardiac effects with local anesthetics.
• Sedatives or general anesthetics: may complicate neurologic and cardiovascular monitoring.
• Hepatic or renal impairment: may increase concern with repeated or high-dose prilocaine exposure.
• Oxytocic or uterotonic context: pregnancy-related risk assessment is important because felypressin is vasopressin-related.
• Compared with epinephrine: clinically significant adrenergic interactions are less likely, but the patient’s full medication list still matters.

• Temporary numbness of lip, cheek, tongue, or soft tissues from the local anesthetic
• Injection-site pain, bruising, or hematoma
• Dizziness, lightheadedness, headache, nausea, or mild drowsiness
• Less racing-heart sensation than epinephrine-containing solutions, but anxiety or vasovagal symptoms can still occur
• Methemoglobinemia from the prilocaine component: cyanosis, shortness of breath, fatigue, abnormal oxygen saturation
• Local anesthetic systemic toxicity: metallic taste, tinnitus, confusion, tremor, seizure, arrhythmia, or collapse
• Rare hypersensitivity reaction
• Post-anesthetic lip, cheek, or tongue biting injury
• Less hemostasis than epinephrine, which may be clinically relevant in surgical procedures

• Do not chew food until the numbness has worn off to avoid biting the lip, cheek, or tongue.
• Children should be supervised while numb because they may bite or suck numb tissues.
• Tell the dentist about pregnancy, possible pregnancy, anemia, lung disease, heart disease, G6PD deficiency, previous blue/gray skin after medicine, and all medications.
• Report previous reactions to dental anesthesia, including fainting, rash, swelling, breathing difficulty, palpitations, persistent numbness, or cyanosis.
• Seek urgent help for blue/gray skin color, breathing difficulty, chest pain, severe dizziness, seizure, confusion, facial swelling, throat swelling, or collapse.
• Contact the clinic if numbness lasts unusually long, altered sensation persists, swelling worsens, severe pain develops, or signs of infection appear.

Felypressin is mainly useful as an adrenaline-free vasoconstrictor with prilocaine. Its memory point is: “less adrenergic stimulation, less hemostasis, pregnancy warning, and prilocaine methemoglobinemia risk.” In an exam or clinic, never discuss felypressin without also discussing prilocaine.

• Blue/gray skin color, shortness of breath, fatigue, dizziness, abnormal oxygen saturation, or chocolate-brown blood
• Cyanosis that does not improve as expected with oxygen
• Metallic taste, circumoral numbness, tinnitus, visual disturbance, agitation, confusion, tremor, slurred speech, or seizure after injection
• Severe dizziness, fainting, collapse, or altered consciousness
• Irregular heartbeat, chest pain, severe hypotension, or cardiovascular collapse
• Difficulty breathing, wheezing, facial swelling, throat swelling, or suspected allergic reaction
• Persistent numbness, tingling, altered sensation, or neurologic symptoms after anesthesia
• Pregnancy with concerning symptoms after exposure requiring medical evaluation
• Any suspected local anesthetic systemic toxicity or methemoglobinemia requiring emergency management

• Prilocaine
• Prilocaine + Felypressin / Octapressin
• Lidocaine + Epinephrine
• Articaine + Epinephrine
• Mepivacaine Plain
• Epinephrine / Adrenaline
• Benzocaine topical anesthetic
• Methylene blue for methemoglobinemia management
• Lipid emulsion therapy for severe local anesthetic systemic toxicity

Felypressin, also known as Octapressin, is a non-catecholamine vasoconstrictor used mainly with prilocaine 3% in dental local anesthetic cartridges. It can provide longer anesthesia than plain solutions while avoiding many epinephrine-like adrenergic effects. However, it is not a perfect substitute for epinephrine: hemostasis is weaker, pregnancy is a major warning, and the prilocaine component adds dose and methemoglobinemia concerns. Safe use requires patient screening, prilocaine milligram calculation, aspiration, slow injection, and awareness that “adrenaline-free” does not mean “risk-free.”