Prilocaine: Uses, Risks, and Practical Tips

Prilocaine is a local anesthetic used to numb skin and deeper tissues for short procedures. You’ll find it in dental injections, minor surgical infiltrations, and topical mixes like EMLA cream (where it’s combined with lidocaine). It works by blocking nerve signals so you feel less pain during procedures.

Because it’s fast-acting and wears off reasonably quickly, clinicians pick prilocaine when short-term numbness is needed. On skin it may take effect within an hour (topical creams need more time) and when injected it often starts in minutes. Duration depends on dose and site—some procedures last under an hour, others a bit longer.

How it’s used

Topical: EMLA (lidocaine + prilocaine) is common for IV starts, skin procedures, and pediatric use. Follow product directions on application time and maximum area. Injected: dentists and surgeons use prilocaine for local infiltration and nerve blocks. You’ll rarely handle dosing yourself; a trained clinician calculates the right amount based on your weight and the procedure.

If you’re a patient, tell your provider about allergies, liver problems, heart disease, or medications. If you’re a clinician, aspirate before injecting and avoid intravascular injection to lower systemic side effects. Consider adding epinephrine to reduce bleeding and prolong effect when appropriate.

Safety tips and side effects

Common local effects are numbness, mild swelling, or a burning sensation at the site. Serious reactions include central nervous system symptoms (dizziness, ringing, tremor, seizures) and cardiovascular signs (slow or irregular heartbeat, low blood pressure) if too much is absorbed. A special risk with prilocaine is methemoglobinemia—an abnormal blood condition where oxygen delivery drops. This can cause shortness of breath, blue skin, or fatigue.

Methemoglobinemia is more likely in infants under six months, people with certain enzyme problems (like G6PD deficiency), or when used with other oxidizing agents (benzocaine, dapsone, nitrates). If symptoms appear, medical treatment with oxygen and, in some cases, methylene blue is effective.

Simple precautions lower risk: use the smallest effective dose, follow topical application times, avoid overlapping topical anesthetics, and warn staff about infants, pregnancy, or enzyme deficiencies. If you feel persistent numbness, breathing problems, or unusual tiredness after an anesthetic, seek help quickly.

Pregnancy and breastfeeding: tell your provider if pregnant or nursing. Providers usually use local anesthetics carefully during pregnancy and pick drugs and doses to protect you and baby. Some topical products are okay in small amounts, but your clinician will advise based on the procedure.

Overdose or severe reaction needs immediate care. Early signs include dizziness, blurred vision, confusion, or twitching. Later you might see seizures or breathing trouble. Call emergency services, give oxygen, and tell responders about the anesthetic. Hospitals can give supportive care and drugs like methylene blue for methemoglobinemia when appropriate promptly.

Final practical notes: bring a list of current meds to appointments, ask how long numbness should last, and avoid chewing or biting numb lips or tongue. For at-home topical use, read and follow label instructions—don’t exceed recommended amounts or use on large broken skin areas.