Novocain (also known as novocaine or novacaine) is the brand name of the anesthetic procaine hydrochloride. Procaine causes loss of feeling (numbness) of skin and mucous membranes. Procaine is a local anesthetic that is used as an injection during surgery and other medical and dental procedures.

How it Works

Novocain works by temporarily decreasing the ability of nerves to transmit information, such as pain.


Novacain is the oldest injectable local anesthetic still in use today. It was synthesized in 1905 by a German chemist, and replaced cocaine as the dominant anesthetic of the time. Today it is still used clinically, but newer local agents, such as lidocaine, have become more common.

Poor Candidates

Procaine should not be administered to people who suffer from the following conditions:

  • Liver problems
  • Bleeding or blood clotting problems
  • Heart problems
  • Other serious medical conditions

Novocain is injected into the blood stream, and this injection alone is enough to make patients nervous about undergoing any sort of dental procedure for which an anesthetic is required. Such patients may want to consider asking for nitrous oxide (or laughing gas). Nitrous oxide is inhaled through a mask clamped over the nose. It relaxes the patient, leading to a state of giddiness. The patient remains awake for the procedure but is much calmer. Nitrous oxide raises the patient's pain threshold, so the Novocain injection is easier to bear.

The Injection

Usually one shot of Novocain should be enough to numb the patient for the duration of any dental procedure. Some patients, however, have "accessory innervation" from nerves in nearby areas such as the neck or under the tongue, especially in cases where the lower molar areas are being anesthetized. These circumstances call for alternative injection techniques. One possibility is a periodontal ligament injection, in which the injection is given between the tooth and gum line.

Side Effects

Along with its desired effects, Novocain may cause some unwanted effects. Most are mild and uncommon, but may include:

Bluish lips and fingernails
Breathing problems
Chest pain
Convulsions (seizures)
Irregular heartbeat
Nausea and/or vomiting
Pale skin
Raised red swellings on the skin, lips,
tongue or in the throat
Rapid heart rate
Unusual tiredness or weakness
Back pain
Difficulty in opening the mouth
Inability to hold bowel movement and/or urine
Loss of sexual function
Paralysis of legs
Persistent numbness
Prolonged tingling of lips and mouth
Skin rash
Tingling or pins-and-needles sensation

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