It combines with pyrophosphate in the body to form a coenzyme, participates in the oxidative decarboxylation reaction of pyruvate and α-ketoglutarate in sugar metabolism, and is necessary for sugar metabolism. When it is deficient, oxidation is blocked to form pyruvate, lactic acid accumulates, and affects the body's energy supply, leading to symptoms of the nervous and cardiovascular systems, including multiple peripheral neuritis, paresthesia, neuralgia, limb weakness, muscle soreness and atrophy; cardiovascular symptoms include dilation of arterioles, decreased diastolic blood pressure, and myocardial metabolic disorders; digestive symptoms include decreased appetite, weakness, and weight loss.

It has local analgesic effect and antiseptic effect

H2 receptor antagonist, significantly inhibits the basal and nocturnal gastric acid secretion in normal people and ulcer patients, as well as the gastric acid secretion caused by pentagastrin, histamine and meals; has a certain inhibitory effect on the secretion of pepsinogen; has a protective effect on experimental gastric mucosal damage and acute ulcers; has no effect on the secretion of gastrin and sex hormones.

1. Effect on water and electrolyte excretion: It can increase the excretion of water, sodium, chloride, potassium, calcium, magnesium, phosphorus, etc.; mainly by inhibiting the active reabsorption of NaCl by the thick-walled segment of the renal tubular loop, reducing the osmotic pressure gradient difference of the medullary interstitial fluid, leading to increased excretion of water, Na+, and Cl-. 2. Effect on hemodynamics: It has a vasodilating effect, can reduce renal vascular resistance, and increase renal blood flow, especially in the deep part of the renal cortex; it can dilate the pulmonary capacitance veins, reduce the permeability of pulmonary capillaries, reduce the amount of blood returning to the heart, and reduce the left ventricular end-diastolic pressure, which is helpful for the treatment of acute left heart failure and adult respiratory distress syndrome.

It selectively excites the medullary respiratory center and can also act on the carotid body and aortic body chemoreceptors to reflexively excite the respiratory center and increase the respiratory center's sensitivity to carbon dioxide, deepening and accelerating breathing. It has a weak excitatory effect on the vasomotor center. Excessive doses can cause convulsions.