Prilocaine / Felypressin

What it is and how it works

Prilocaine blocks voltage-gated sodium channels in nerve membranes, preventing initiation and conduction of nerve impulses and producing reversible local anaesthesia. Felypressin, a synthetic vasopressin analogue, causes local vasoconstriction that prolongs the anaesthetic effect and reduces systemic absorption, without the adrenergic cardiovascular effects of adrenaline.

Indications

Local anaesthesia by infiltration or nerve block in dental procedures, particularly where adrenaline-containing anaesthetics are undesirable.

Dosage and administration (summary)

By dental infiltration or nerve block; the volume depends on the procedure (often one cartridge or less is sufficient), using the lowest dose that achieves adequate anaesthesia and not exceeding the maximum recommended prilocaine dose in the product information.

Contraindications

Hypersensitivity to amide local anaesthetics, congenital or idiopathic methaemoglobinaemia, severe anaemia, and intravascular injection.

Warnings and precautions

Prilocaine can cause methaemoglobinaemia, particularly at high doses or with other oxidising drugs; aspirate before injection to avoid intravascular administration. Caution is required in cardiac disease, epilepsy, hepatic or renal impairment and in elderly or debilitated patients; systemic toxicity may cause CNS excitation, seizures and cardiovascular depression.

Pregnancy

Felypressin may have oxytocic effects, so alternatives are generally preferred in pregnancy, particularly late pregnancy.

Storage and supply

Store below 25 °C; do not freeze; protect from light.

Source: reference summary prepared from the EU SmPC/EPAR, BNF and WHO Model Formulary. The approved product information in Iran governs.