Propitocaine hydrochloride

Biological Functions

Prilocaine hydrochloride (Citanest) is an amide anesthetic whose onset of action is slightly longer than that of lidocaine; its duration of action is comparable. Prilocaine is 40% less toxic acutely than lidocaine, making it especially suitable for regional anesthetic techniques. It is metabolized by the liver to orthotoluidine, which when it accumulates, can cause conversion of hemoglobin (HB⁺⁺⁺ to methemoglobin (HB⁺⁺⁺. Oxygen transport is impaired in the presence of methemoglobinemia. Treatment involves the use of reducing agents, such as methylene blue, given intravenously, to reconvert methemoglobin to hemoglobin.

Side Effects

Common adverse reactions include bradycardia, hypotension, urticaria, edema, anaphylactoid reactions, lightheadedness, nervousness, euphoria, confusion, dizziness, drowsiness, tinnitus. The safety and effectiveness of prilocaine depend on proper dosage, correct technique, adequate precautions, and readiness for emergencies.

The Uses of Propitocaine hydrochloride

Propitocaine hydrochloride is a local anesthetic of the amino amide type,it is often used in dentistry. Prilocaine is also often combined with lidocaine as a preparation for dermal anesthesia (lidocaine/pril ocaine or EMLA), for treatment of conditions like paresthesia. 

Synthesis

The synthetic method includes the following steps that a, ortho-toluidine is added into dichloromethane, alpha-propionyl chloride is dropwise added at the room temperature, and the reaction lasts for 2-3 h at the temperature of 15 DEG C-25 DEG C, acid solution washing is performed on the obtained reaction liquid, then, aqueous alkali washing is performed on the obtained reaction liquid, water is added to an organic layer to separate solids out, and then propitocaine hydrochloride midbody is obtained through filtration; b, the propitocaine hydrochloride midbody obtained in the step a is added into n-propylamine, reflux is heated for 5-7 h, after the reaction is ended, concentrated hydrochloric acid is added to adjust the PH to be 1-2, white solids are separated out and are refined through ethyl alcohol of 95%, and therefore the propitocaine hydrochloride is obtained.