Pyramidon

Pyramidon, Pyramidonum, Pyrazolonum dimethylamino - phenyldimethylicum, диметиламиноантипирин (synonyms: amidopyrin, Amido-pyrinum) (Ph. VII), mol. w. 231.2, C13H16N3O. It is obtained from antipyrine, which with nitric acid is converted to isonitrosoantipyrine; the latter is reduced to aminoantipyrine, which is then methylated. A white or slightly yellow crystalline powder, melting at 108°, slowly soluble in 18-20 parts of water, easily soluble in alcohol. The aqueous solution has a weakly alkaline reaction on litmus; after acidification with ferric chloride gives a blue-violet coloration. P. has a slightly bitter taste, irritates the mucous membranes slightly (less than antipyrin), is well absorbed by the intestine and is generally completely destroyed in the body. Urine after taking pyramidon is colored red (more intense than with antipyrin) due to the presence of rubazonic acid (a pyrazolone derivative). Small amounts of undestroyed P. can be detected in urine by the Jolles reaction: the addition of tincture of iodine leads to the appearance of a violet ring, which after some time becomes reddish-brown. P. was proposed in 1896 by Filehne as an antipyretic and antineuralgic agent, 3-4 times stronger than antipyrin (see). In a healthy person, P. in a dose of 0.3-0.5 g causes moderate dilation of superficial vessels (mainly of the head) and slight sweating; despite the resulting increase in heat dissipation (up to 20-30% above normal), there is no drop in body temperature due to compensatory increase in heat production (Gottlieb). In febrile patients, P. causes a more significant increase in heat dissipation with a significant decrease in body temperature, which, as with antipyrine and other antipyretics, occurs due to its effect on abnormally functioning thermoregulation (area of the gray tubercle). The antipyretic effect of P. compared to antipyrine differs in that it develops more slowly and lasts longer, which represents important therapeutic advantages. The analgesic effect of P. also has a central origin (area of the optic tubercles), in which the ability of P. to dilate vessels (e.g., in migraine) also participates. Dilation of the vessels of the skin and brain occurs simultaneously with constriction of the vessels of the internal organs, why blood pressure does not change (and in some cases may slightly increase). Cardiac activity under the influence of P. hardly changes and at therapeutic doses this effect is insignificant. With significant overdose, dizziness, weakness, convulsions and finally collapse occur. Convulsive symptoms are also characteristic of poisoning in 7 21 experimental animals. P. (like antipyrine) unlike some other antipyretics does not change the blood pigment. Side effects and idiosyncratic reactions occur less frequently than with antipyrine. The use of P. leads to some habituation. P. is extremely widely used as an antineuralgic and antipyretic. Its analgesic effect is so significant that P. can in many cases replace morphine. The significant improvement in the condition of febrile patients, occurring due to the decrease in temperature, elimination of headaches and other pains, severe malaise, insomnia, etc., gives reason for the frequent use of P. both in acute febrile diseases (typhoid, etc.), especially where water treatment procedures are difficult, and in chronic (tuberculosis), especially outside hospital or sanatorium conditions. In the first years of use of P., its favorable effect in acute articular rheumatism (Pauli, Hoffmann, Korovitsky, etc.) was discovered without P. being considered particularly indicated for this disease. In recent years, Schottmüller and his clinic attribute to P. a specific effect in this disease, in many cases not only not inferior to, but surpassing the effect of salicylates. Schottmüller recommends repeated administration of P. in doses of 0.3 to 1.5-3.0 pro die (i.e., exceeding the maximum daily dose). P. is also used in fractional doses (0.5 : : 200.0 every ^g/₂ hour by the tablespoon) to reduce temperature and eliminate exhausting sweats in tuberculosis patients. A feature of P.'s action is its property to lower temperature only of infectious origin, which gave reason to use it for diagnostic purposes (see Thermoregulation). Finally, P. is also used as a reagent for blood pigment. Preparations. Pyramidonum (Amidopyrinum)-for administration, highest dose 0.5, per day 1.5 (Ph. VII); Pyramidonum camphoricum-0.5 (0.75); P. bicamphoricum-0.75 (1.0). The last two preparations were proposed to limit the sweating caused by P. in febrile patients (effect of camphoric acid); P. salicylicum-0.5 (0.75); Citrovanille-a preparation consisting mainly of citric acid P.; Veramon - a combination of P. with veronal (0.4-0.6); Compral - a combination of P. with voluntal. Numerous analogues and combinations have been proposed, such as melubrine-antipyrine-amido-methane-sulfonic acid sodium, novamidon-dimethyl-amino-phenyl-dimethyl-pyrazolone and many others, but they have not received particular spread compared to pyramidon.

B. Karasik. Discovery in forensic cases. P. is extracted with chloroform from an alkaline solution along with alkaloids. It dissolves in 30 parts of water with the formation of an alkaline solution reaction on "litmus. The discovery reactions for P. are based on its oxidation with the formation of intermediate products colored violet (or blue), which disappear from excess of the reagent. Reactions: 1) ferric chloride gives violet coloration, 2) nitric acid (acidified solution of sodium nitrite)-violet coloration, 3) silver nitrate-blue, then precipitation of gray metallic silver.