pramocaine

Absorption

There is minimal absorption after topical administration and it is not given orally.

Toxicity

LD50 Mouse ip 300 mg/kg, LD50 Mouse sc 750 mg/kg

Originator

Tronothane, Abbott, US ,1954

The Uses of pramocaine

Anesthetic (topical).

Indications

It is indicated for temporary relief of pain and pruritus from minor lip and skin irritations as well as for temporary relief from pain, burning, itching and discomfort associated with hemorrhoids and other anorectal/anogenital disorders.

Background

Pramocaine (also known as pramoxine or pramoxine HCI) is a topical anesthetic and antipruritic. It is used for many dermatological and anorectal/anogenital conditions including minor cuts/burns, insect bites, hives/rashes due to poison ivy exposure, hemorrhoids and other anorectal/anogenital disorders. Pramocaine is available by itself and in combination with other medications in various topical preparations. It works by preventing ionic fluctuations needed for neuron membrane depolarization and action potential propagation.

Definition

ChEBI: A member of the class of morpholines that is morpholine substituted at the nitrogen atom by a 3-(4-butoxyphenoxy)propyl group.

Manufacturing Process

About 5.6 g of potassium hydroxide is dissolved in about 150 cc of refluxing ethanol, and then about 16.6 g of hydroquinone monobutyl ether is added to the alcoholic solution. When the hydroquinone is dissolved, about 16.3 g of γmorpholinopropyl chloride (dissolved in a small amount of ethanol) is added to the refluxing solution. The solution is refluxed for about 24 hours and then cooled. The product is recovered by filtering the reaction mixture and then removing the solvent by vacuum distillation. The oily residue is acidified and shaken with ether. The acidic phase is made strongly alkaline with 40% sodium hydroxide, and the oil which separates is extracted into ether. The ethereal phase is dried, and the solvent removed by vacuum distillation. The product distills at 183° to 184°C at a pressure of 2.8 mm. The hydrochloride salt of the foregoing base is prepared by dissolving the base in ether and acidifying with hydrochloric acid and is found to have a MP of 181° to 183°C.

brand name

Tronolane (Ross); Tronothane (Abbott).

Therapeutic Function

Local anesthetic

Pharmacokinetics

Pramocaine temporarily relieves pain, pruritis, burning and discomfort associated with minor lip and skin irritations and hemorrhoid's by inhibiting voltage gated sodium channels on neurons.

Metabolism

Not Available