Felypressin
The vasoconstrictor mixed into prilocaine dental cartridges as an alternative to adrenaline, never approved in the US
Local anaesthetics wear off faster when blood carries them away, so a vasoconstrictor is usually added. Adrenaline is the common choice; felypressin, a synthetic vasopressin analogue, is the alternative in prilocaine cartridges sold in Europe, Japan and elsewhere. Its effect on blood pressure is the question its trials keep asking.
What is it?
A local anaesthetic lasts as long as it stays where it was injected. Adding a vasoconstrictor narrows nearby blood vessels, slows its removal and reduces bleeding. Adrenaline does this through adrenergic receptors and can raise heart rate. Felypressin acts on vasopressin V1 receptors instead, which is why it was offered to patients for whom adrenaline is a worry.
Studies in the 1960s mapped its effects in people: low doses widened kidney blood vessels and raised blood pressure slightly, while higher doses constricted vessels elsewhere sharply. Applied to dental and minor surgical use, that profile is the reason its dosing has been studied so closely in people with high blood pressure.
The trials give a mixed picture. In patients with essential hypertension, a dose-finding study put the clinically safe limit at about 0.18 IU, and found no ischaemic change on the heart even at the highest dose. A 2012 study of 71 hypertensive patients found blood pressure rose during dental treatment with or without felypressin. In cervical procedures, prilocaine with felypressin caused fewer side effects than lignocaine with adrenaline, at the cost of more bleeding.
In everyday use it works. Prilocaine with felypressin cut pain in placebo-controlled trials of cervical treatment, and a nerve block using it lasted longer than an adrenaline-lidocaine block. The cardiovascular questions remain: in diabetic men with coronary disease, pulse pressure rose more after a standard dental dose, and in rabbits felypressin reduced the heart's own blood flow and oxygen at doses equivalent to a few cartridges, where adrenaline did not.
Felypressin is approved as an ingredient of dental anaesthetic products in the UK, much of Europe, Japan, Brazil and Australia, among others. It has never been approved in the US.
Mechanism of Action
Felypressin is a synthetic vasopressin analogue that constricts blood vessels through V1 receptors, used to keep local anaesthetic where it is injected.
V1-receptor vasoconstriction
Narrows vessels through vasopressin V1 receptors rather than adrenergic ones, so it does not stimulate the heart the way adrenaline does.
Longer anaesthesia
Slows removal of the anaesthetic; a felypressin-prilocaine block lasted about 40 minutes longer than epinephrine-lidocaine.
Coronary caution
In animals it reduced coronary blood flow and myocardial oxygen; in diabetic men with coronary disease, pulse pressure rose more.
Published Research
These are the studies that describe felypressin, read from their PubMed abstracts: two in hypertensive dental patients, two randomised gynaecological trials and an early study of its circulation effects.
A safe dose in hypertension
Patients with essential hypertension received prilocaine with felypressin at increasing concentrations. Blood pressure rose at the higher doses, but no ischaemic change in the heart appeared even at the highest; the authors put the safe limit at about 0.18 IU.
Blood pressure in the dental chair
71 patients with controlled hypertension had prilocaine with and without felypressin before deep scaling. Systolic pressure rose after anaesthesia regardless of felypressin, throughout the procedure, a finding the authors linked partly to anxiety.
Against lignocaine with adrenaline
200 women having cervical loop excision were randomised to prilocaine with felypressin or lignocaine with adrenaline. Adrenaline gave less blood loss but more side effects such as feeling faint and shaking; felypressin caused few side effects.
What it does to circulation
In patients with hypotension or cirrhosis, low infusion rates increased kidney blood flow and slightly raised arterial pressure, while higher rates sharply raised pressure and systemic resistance, redistributing blood towards the kidney.
Wisdom-tooth extraction and the heart's rhythm
In 40 women having an impacted third molar removed, prilocaine-felypressin shifted heart-rate variability toward sympathetic dominance more than lidocaine-epinephrine; systolic pressure rose throughout surgery in both groups.
Diabetic men with heart disease
After 3% prilocaine with felypressin 0.03 IU/mL, pulse pressure rose 15.6 mmHg in diabetic men with coronary heart disease against 4.3 in those without.
A nerve block with felypressin-prilocaine
In 40 healthy students, an anterior inferior alveolar block with felypressin-propitocaine was as successful as a conventional epinephrine-lidocaine block, lasted about 40 minutes longer and hurt less to inject.
Cervical treatment: placebo-controlled
In 100 women having cervical biopsy and treatment, intracervical prilocaine with felypressin significantly reduced pain and abolished severe pain compared with placebo.
Laser treatment of the cervix
Infiltrating 2 mL of prilocaine 3% with felypressin 0.03 IU/mL before laser vaporisation reduced pain on a visual analogue scale against no anaesthetic.
Heart oxygen at dental doses
In rabbits given doses equivalent to 2 to 8 dental cartridges, felypressin, but not epinephrine, lowered aortic and myocardial blood flow and myocardial oxygen tension.
Through V1 receptors
In rats, felypressin's rise in blood pressure and slowing of the heart depended on vasopressin V1 receptors; epinephrine raised pressure more.
Dosing Data
It is not approved in the US. Elsewhere it comes premixed in dental cartridges at 0.03 IU/mL with 3% prilocaine; a study in hypertension put the safe limit at about 0.18 IU.
Educational information, not medical advice. Each dose above is tagged with its source: an approved label, a published human study, animal data, or amounts reported by users. None is a recommendation for you. An unapproved compound has no established safe or effective human dose, and products sold for “research use only” are not made or tested for people. Talk to a doctor before acting on anything on this site, including before you start, stop or change any medicine or dose. Full medical disclaimer.
Side Effects & Contraindications
Reported Side Effects
From the trials above and the products that contain it.
Contraindications & Cautions
An ingredient of prescription anaesthetic products outside the US.
Legal Status
Felypressin is approved outside the US, as an ingredient of dental anaesthetics.
Frequently Asked Questions
?What is felypressin?
A synthetic analogue of vasopressin added to prilocaine dental anaesthetics to make them last longer, as an alternative to adrenaline.
?Why use it instead of adrenaline?
It narrows blood vessels through vasopressin receptors rather than adrenergic ones, so it avoids adrenaline's effects on heart rate.
?Is it safe with high blood pressure?
Within limits. One study put the safe dose in essential hypertension at about 0.18 IU, and blood pressure rose at higher doses.
?Is it available in the US?
No. It is approved in the UK, much of Europe, Japan and elsewhere, but never in the US.
?Does it work as well as adrenaline in anaesthetic?
In a trial in 40 students, a felypressin-prilocaine nerve block was as successful as an epinephrine-lidocaine block, lasted about 40 minutes longer and was less painful to inject.
References
- [pubmed] Sunada K, et al. "Clinically safe dosage of felypressin for patients with essential hypertension." Anesth Prog, 1996;43(4):108-15. PMID: 10323116.
- [pubmed] Bronzo AL, et al. "Felypressin increases blood pressure during dental procedures in hypertensive patients." Arq Bras Cardiol, 2012;99(2):724-31. PMID: 22735869.
- [pubmed] Howells RE, et al. "A comparison of the side effects of prilocaine with felypressin and lignocaine with adrenaline in large loop excision of the transformation zone of the cervix: results of a randomised trial." BJOG, 2000;107(1):28-32. PMID: 10645858.
- [pubmed] Cohn JN, et al. "Systemic vasoconstrictor and renal vasodilator effects of PLV-2 (octapressin) in man." Circulation, 1968;38(1):151-7. PMID: 11712284.
- [pubmed] Jastak JT, et al. "Vasoconstrictors and local anesthesia: a review and rationale for use." J Am Dent Assoc, 1983;107(4):623-30. PMID: 6355236.
- [other] US FDA, Drugs@FDA (openFDA): no application for felypressin. Read September 30, 2026.
- [other] Dentsply Sirona. Citanest with Octapressin Dental, Summary of Product Characteristics (UK): prilocaine 3% with felypressin 0.54 µg/mL. Read October 5, 2026.
- [other] Australian Commission on Safety and Quality in Health Care, Medicine Finder: 3% Citanest Dental with Octapressin (prilocaine hydrochloride + felypressin). Read October 5, 2026.
- [other] Medsafe (New Zealand). 3% Citanest DENTAL with Octapressin data sheet, Dentsply Sirona (NZ). Read October 5, 2026.
- [pubmed] Yamashita K, et al. "Difference in the Effects of Lidocaine With Epinephrine and Prilocaine With Felypressin on the Autonomic Nervous System During Extraction of the Impacted Mandibular Third Molar: A Randomized Controlled Trial." J Oral Maxillofac Surg, 2020;78(2):215.e1-215.e8. PMID: 31654643.
- [pubmed] Kubota K, et al. "Increase in pulse pressure on administration of a dental local anesthetic solution, prilocaine hydrochloride with felypressin in male diabetic patients with coronary heart disease." Clin Oral Investig, 2020;24(1):239-246. PMID: 31079247.
- [pubmed] Shinzaki H, et al. "Advantages of anterior inferior alveolar nerve block with felypressin-propitocaine over conventional epinephrine-lidocaine: an efficacy and safety study." J Dent Anesth Pain Med, 2015;15(2):63-68. PMID: 28879260.
- [pubmed] Duncan ID, et al. "A double-blind, randomized, placebo-controlled trial of prilocaine and felypressin (Citanest and Octapressin) for the relief of pain associated with cervical biopsy and treatment with the Semm coagulator." J Low Genit Tract Dis, 2005;9(3):171-5. PMID: 16044058.
- [pubmed] Lee ET, et al. "A randomized trial of Citanest with Octapressin for relief of pain associated with laser vaporization of the cervix." Br J Obstet Gynaecol, 1986;93(9):967-9. PMID: 2429687.
- [pubmed] Inagawa M, et al. "Felypressin, but not epinephrine, reduces myocardial oxygen tension after an injection of dental local anesthetic solution at routine doses." J Oral Maxillofac Surg, 2010;68(5):1013-7. PMID: 20031290.
- [pubmed] Cecanho R, et al. "Cardiovascular effects of felypressin." Anesth Prog, 2006;53(4):119-25. PMID: 17177590.
Sources & Citations
Studies were read from their PubMed abstracts; no US label exists. Read October 7, 2026.
Medical Disclaimer: This content is for educational and informational purposes only. It is not medical advice, and nothing here is an instruction to obtain or use any compound. Talk to a licensed clinician about your own situation.