Adding vasoconstrictors to local anaesthetics
Local anaesthetics may be used in combination with a vasoconstrictor to prolong local anaesthetic effects. Vasoconstriction reduces the rate of local anaesthetic loss to the circulation and reduces bleeding, both during and after the procedure.
Adrenaline (epinephrine) is a commonly used vasoconstrictor in dental practice. Avoid adrenaline-containing solutions in patients with known sensitivity to sulfites1, because metabisulfites are used as a preservative. If adrenaline cannot be used, local anaesthetic solutions containing felypressin or solutions without a vasoconstrictor are alternatives.
Felypressin is an alternative vasoconstrictor to adrenaline (epinephrine) because it has minimal effects on the myocardium at the concentration used in dental cartridges (0.03 international units/mL). Felypressin is safe for dental use in pregnant patients, although previously this was contraindicated.