Histamine

Pharmaceutical

Pharmaceuticals -> Listed in ZINC15

-0.70

-0.7

COLORLESS LONG PRISMATIC CRYSTALS; ODORLESS; 1 G SOL IN ABOUT 4 ML WATER; AQ SOLN IS ACID TO LITMUS; WHEN DRIED AT 105 °C FOR 2 HR, IT MELTS AT ABOUT 140 °C /PHOSPHATE/

FREELY SOL IN WATER, ALCOHOL, HOT CHLOROFORM; SPARINGLY SOL IN ETHER

14.1 [ug/mL] (The mean of the results at pH 7.4)

83-84 °C

86 °C

9.756

PKA1= 9.68; PKA2= 5.88

120.4 Ų [M+H]+ [CCS Type: DT; Method: single field calibrated with ESI Low Concentration Tuning Mix (Agilent)]

120 Ų [M+H]+ [CCS Type: DT; Method: single field calibrated with Agilent tune mix (Agilent)]

120.4 Ų [M+H]+

DELIQUESCENT

PRISMS FROM ETHANOL; MP: 244-246 °C; FREELY SOL IN WATER, METHANOL /DIHYDROCHLORIDE/

This chemical does not meet GHS hazard criteria for 6.7% (3 of 45) of reports.

Danger

H301 (93.3%): Toxic if swallowed [Danger Acute toxicity, oral]

P233, P260, P261, P264, P264+P265, P270, P271, P272, P280, P284, P301+P316, P302+P352, P304+P340, P305+P351+P338, P319, P321, P330, P332+P317, P333+P317, P337+P317, P342+P316, P362+P364, P403, P403+P233, P405, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 45 reports by companies from 5 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

INHIBITORY EFFECT OF METHAMIDE (POTENT H2 ANTAGONIST) ON GASTRIC ACID SECRETION ELICITED BY CONTINUOUS HISTAMINE IV INFUSION IN MAX EFFECTIVE DOSE (20 UMOLE/HR) IN DOGS IS SHOWN TO BE APPROX 20%/10 UMOLE/KG AFTER 1.5 HR. COMPARABLE EFFECTS WERE OBSERVED IN NORMAL HUMANS IN SAME STUDY. /H2-RECEPTOR ANTAGONISTS, FROM TABLE/

IN GUINEA PIGS, DEATH BY ASPHYXIA FOLLOWS QUITE SMALL DOSES OF HISTAMINE, YET ANIMAL MAY SURVIVE A HUNDRED LETHAL DOSES OF HISTAMINE IF GIVEN AN H1-BLOCKING DRUG. IN SAME SPECIES, H1 ANTAGONISTS OFFER STRIKING PROTECTION AGAINST ANAPHYLACTIC BRONCHOSPASM, BUT THIS IS NOT SO IN MAN... /H1-RECEPTOR ANTAGONISTS/

OCCURS WIDELY IN NATURE AS A RESULT OF PUTREFACTIVE PROCESSES.

.../HISTAMINE/ IS A NATURAL CONSTITUENT OF BODY. ... LIBERATED FROM CELLS OF SKIN BY INJURIOUS STIMULI.../&/ INVOLVED IN MANY... DIVERSE PHYSIOLOGICAL PROCESSES...HISTAMINE RECEPTORS...FALL INTO 2 BROAD CLASSES: H1 & H2...

HISTAMINE IS WIDELY, IF UNEVENLY, DISTRIBUTED THROUGHOUT ANIMAL KINGDOM & IS PRESENT IN MANY VENOMS, NOXIOUS SECRETIONS, BACTERIA & PLANTS.

OVERDOSAGE WITH HISTAMINE IS RARE, & SYMPTOMS ARE GENERALLY NOT DANGEROUS. HOWEVER, MASSIVE DOSES CAUSE INTENSE HEADACHE, FLUSHING, PROFOUND FALL OF BLOOD PRESSURE, BRONCHOSPASM, DYSPNEA, A METALLIC TASTE, VOMITING & DIARRHEA.

.../EYE EFFECT/ OF AN 8% SOLN OF HISTAMINE HYDROCHLORIDE HAS BEEN DESCRIBED IN CASE OF GIRL WHO SPILLED SOME...ON HER HANDKERCHIEF & CONTAMINATED HER RIGHT EYE... IN 10 MIN CONJUNCTIVAE BECAME HYPEREMIC & LIDS EDEMATOUS, WITHOUT DISCOMFORT. REACTION HAD NEARLY DISAPPEARED IN 5 HR & COMPLETELY GONE NEXT DAY... /HCL SALT/

IN SOME HUMAN GLAUCOMATOUS EYES, APPLICATION OF 3% HISTAMINE HYDROCHLORIDE EYEDROPS HAS BEEN KNOWN TO CAUSE RISE IN OCULAR PRESSURE, PARTICULAR IN CASES OF ACUTE GLAUCOMA. /HCL SALT/

...INJECTED INTRADERMALLY...TRIPLE RESPONSE /FOLLOWS/...RED SPOT...BRIGHTER RED...FLARE...DEVELOPING...MORE SLOWLY, &...LOCALIZED EDEMA...DUE TO LOCAL DILATATION OF MINUTE BLOOD VESSELS /&/...DILATATION OF NEIGHBORING ARTERIOLES.../& EDEMA/ DUE TO DIRECT ACTION...ON WALLS OF...VESSELS TO INCR THEIR PERMEABILITY.

IN MOST EXPTL SUSCEPTIBLE SPECIES (CALVES, SWINE, DUCKS, GUINEA PIGS, CATS, DOGS), IM INJECTIONS OF HISTAMINE IN BEESWAX AT RATE OF 1-4 MG/KG/DAY PRODUCES GASTRIC ULCERS WITHIN 1-6 WK.

EXPT ON EXCISED BEEF CORNEAS HAVE DEMONSTRATED THAT HISTAMINE AT CONCN AS LOW AS 0.000005 MOLAR HAS AN UNUSUAL CAPACITY FOR LOOSENING SUPERFICIAL EPITHELIAL CELLS FROM BASAL CELLS OF CORNEA AFTER SEVERAL HR OF INCUBATION.

Histamine acts directly on the blood vessels to dilate arteries and capillaries; this action is mediated by both H 1- and H 2-receptors. Capillary dilatation may produce flushing of the face, a decrease in systemic blood pressure, and gastric gland secretion, causing an increased secretion of gastric juice of high acidity. Increased capillary permeability accompanies capillary dilatation, producing an outward passage of plasma protein and fluid into the extracellular spaces, an increase in lymph flow and protein content, and the formation of edema. In addition, histamine has a direct stimulant action on smooth muscle, producing contraction if H 1-receptors are activated, or mostly relaxation if H 2-receptors are activated. Also in humans, the stimulant effect of histamine may cause contraction of the intestinal muscle. However, little effect is noticed on the uterus, bladder, or gallbladder. Histamine has some stimulant effect on duodenal, salivary, pancreatic, bronchial, and lacrimal glands. Histamine also can bind to H3 and H4 receptors which are involved in the CNS/PNS neurotransmitter release and immune system chemotaxis, respectively.

...CONTRACTS MANY SMOOTH MUSCLES, SUCH AS...BRONCHI & GUT, BUT...RELAXES OTHERS...OF FINE BLOOD VESSELS. IT IS...POTENT STIMULUS TO GASTRIC ACID PRODUCTION & ELICITS...OTHER EXOCRINE SECRETIONS. ...BRONCHOCONSTRICTION & CONTRACTION OF GUT...INVOLVE H1 RECEPTORS...GASTRIC SECRETION...INVOLVE ACTIVATION OF H2 RECEPTORS...

...AT CELLULAR LEVEL, MANY RESPONSES TO HISTAMINE ARE CLEARLY ATTRIBUTABLE TO INCR IN MEMBRANE PERMEABILITY THAT ALLOWS COMMON INORG IONS (MAINLY CATIONS) TO FLOW DOWN ELECTROCHEM GRADIENTS & ALTER TRANSMEMBRANE POTENTIAL. IT DOUBTLESS EXPLAINS STIMULANT ACTIONS...OF HISTAMINE ON NERVE ENDINGS OR GANGLION CELLS...

...ESSENTIALLY SIMILAR ACTION /TO THAT AT CELLULAR LEVEL/ APPEARS TO ACCOUNT FOR SECRETION, AT LEAST AS IT OCCURS IN CHROMAFFIN CELLS OF ADRENAL MEDULLA. HERE HISTAMINE...MIMIC PHYSIOLOGICAL SECRETAGOGUE ACH IN DEPOLARIZING THE PLASMALEMMA.

MODE OF ACTION OF HISTAMINE...TO PRODUCE SMOOTH MUSCLE RELAXATION, INCL VASODILATION, HAS NOT BEEN DEFINED.

CLASSICAL...ANTIHISTAMINES ARE...CAPABLE OF BLOCKING...H1 RECEPTORS ONLY... H2 RECEPTORS...ARE INHIBITED PREFERENTIALLY BY H2-RECEPTORS ANTAGONISTS.

Primarily hepatic. Histamine is rapidly metabolized by methylation and oxidation. Methylation involves ring methylation and catalyzation by the enzyme histamine-N-methyltransferase, producing N-methylhistamine, which is mostly converted to N-methyl imidazole acetic acid. 2 to 3% excreted as free histamine, 4 to 8% as N-methylhistamine, 42 to 47% as N-methyl imidazole acetic acid, 9 to 11% as imidazole acetic acid, and 16 to 23% as imidazole acetic acid riboside.

IN MAN THERE ARE 2 MAJOR PATHS OF HISTAMINE METAB. MORE IMPORTANT ONE INVOLVES RING METHYLATION & IS CATALYZED BY...HISTAMINE-N-METHYLTRANSFERASE (IMIDAZOLE-N-METHYLTRANSFERASE, INMT). MOST OF PRODUCT, METHYLHISTAMINE, IS CONVERTED BY MONOAMINE OXIDASE TO METHYL IMIDAZOLE ACETIC ACID (METHYL IMAA).

IN OTHER PATH, HISTAMINE UNDERGOES OXIDATIVE DEAMINATION CATALYZED MAINLY BY DIAMINOXIDASE (DAO), ALSO CALLED "HISTAMINASE"... THE PRODUCTS ARE IMIDAZOLE ACETIC ACID (IMAA) &, EVENTUALLY, ITS RIBOSIDE.

.../MUCH OF VERY LARGE AMT OF HISTAMINE GIVEN ORALLY/ IS CONVERTED BY INTESTINAL BACTERIA TO N-ACETYLHISTAMINE.

Readily absorbed after parenteral administration.

HISTAMINE IS READILY ABSORBED AFTER PARENTERAL INJECTION...

THE VARIOUS METAB, WHICH HAVE LITTLE OR NO PHARMACOLOGICAL ACTIVITY, ARE EXCRETED IN URINE.

HISTAMINE & N-METHYLHISTAMINE ACCUM IN TISSUE DEPOTS.

HISTAMINE PHOSPHATE, USP, & HISTAMINE DIHYDROCHLORIDE... HISTAMINE PHOSPHATE INJECTION, USP, CONTAINS 1 MG OF SALT (0.36 MG OF HISTAMINE BASE) IN 1 ML. OTHER AVAIL PREPN CONTAIN 0.275 & 2.75 MG OF HISTAMINE PHOSPHATE IN 1 ML (0.1 & 1 MG OF HISTAMINE BASE IN 1 ML), & ARE PACKAGED IN 1- OR 5-ML AMPULES.