What Is Aminopyrine?
Aminopyrine is a pyrazolone derivative, appearing as a colorless or white crystalline solid. It is used in a 13C-labeled aminopyrine breath test, a non-blood test for assessing the metabolic activity of cytochrome P450 in liver function tests.
Uses of Aminopyrine
Initially marketed by Hoechst as an antipyretic analgesic, aminopyrine works by inhibiting the synthesis of prostaglandins, which cause fever and pain and has analgesic properties due to its action on the hypothalamus. However, due to its side effects, including agranulocytosis and carcinogenic potential, it is no longer used as an antipyretic analgesic.
Properties of Aminopyrine
Aminopyrine is soluble in chloroform, ethanol, ether, and water, with a melting point of 225-228°F. It has a slightly bitter taste and no odor, and its chemical formula is C13H17N3O. The molecular weight is 231.29358, and it is sensitive to light, turning blue to purple in the presence of oxidants.
Other Information on Aminopyrine
1. Synthesis of Aminopyrine
Aminopyrine was first synthesized in 1884 by Ludwig Knorr from antipyrine, hydrochloric acid, and sodium nitrite, and later refined by Wilhelm Filehne.
2. Comparison of Aminopyrine Efficacy
Aminopyrine is more potent than antipyrine, with a stronger analgesic effect than antipyrine and isopropylantipyrine.
3. Side Effects of Aminopyrine
Aminopyrine has been associated with agranulocytosis and nitrosation reactions in the gastrointestinal tract. The injectable form is currently used only in some veterinary drugs.
4. Pharmacokinetics of Aminopyrine
In the body, aminopyrine is bound to urea through glucuronidation, converted to rubazonic acid, and excreted in the urine, which appears reddish.
5. Related Compounds of Aminopyrine
Aminopyrine is a pyrazolone derivative, a class of heterocyclic compounds with a five-membered ring lactam structure. Pyrazolone derivatives include antipyrine and isopropylantipyrine.