Local anesthetic drug
Prilocaine belongs to amide local anesthetic drug with its anesthesia intensity and speed being similar as lidocaine but with a longer duration period and weaker effect on vasodilation. It has a lower toxicity than lidocaine. It is clinically for local anesthesia, especially suitable for treating patients who are not allowed to use adrenaline.
[Pharmacological] its 3% solution has a similar local anesthesia efficacy as the anesthesia drug of 2% lidocaine together with adrenaline. It has a slow onset time which lasts about 6~7min and the duration time of about 1.5~2h. It has a strong penetration capability through mucous membranes. Adrenaline has a slightly prolonged duration of action. PPB is 55% and T1/2 of about 1.5h. It is subject to liver metabolism with its metabolites nitroso toluidine being able to oxidize hemoglobin to form methemoglobin. It can be transported to the fetus through the placenta.
[Adverse reactions] once the usage amount exceeds 600mg, methaemoglobinaemia can occur with cyanosis, tachycardia, headache, dizziness and weakness occurring.
[Note] patients of anemia, congenital or acquired methaemoglobinaemia, respiratory failure or heart failure and hypoxic patients should be disabled. It is forbidden for applied to obstetric anesthesia.
[Usage and dosage] infiltration anesthesia: 0.5% to 1% solution with the duration of action of 1 to 1.5 hours.
Nerve blocking anesthesia: use 1% to 2% solution with the duration of action being 2-3 hours.
Epidural anesthesia: use10 to 30 mL of 1.5%~1% solution with the duration of action of 2.5 to 3.5 hours. Use a maximum dose of 600 mg.
Figure 1 the structural formula of prilocaine
The above information is edited by the Chemicalbook of Dai Xiongfeng.
O-toluidine and α-bromo-propionyl bromide are condensed and further have reaction with propylamine obtain prilocaine.
It is a kind of needle-like crystals with the melting point being 37-38 ℃ and the boiling point being 159-162 ℃ (0.133kPa), and refractive index (nD20) being 1.5299. Its hydrochloride ([1786-81-8]) is a white crystalline powder. The Melting point is 167-168 ℃. It is soluble in water and ethanol, slightly soluble in chloroform. It has sour taste and bitter taste and is odorless.
It is a kind of local anesthetic drug. The product has better efficacy than procaine and the local anesthesia intensity and speed being similar as lidocaine but with longer duration time and less toxicity as well as smaller accumulation effect. It is suitable for epidural anesthesia, conduction anesthesia and infiltration anesthesia.
ChEBI: An amino acid amide in which N-propyl-DL-alanine and 2-methylaniline have combined to form the amide bond; used as a local anaesthetic.