Nature of Nitrofurantion

Nitrofurantoin is also named Furradine, Furan, Furantoin, Macrodantin, Urantoin. Nitrofurantion is bright yellow crystalline powder; odorless, bitter taste; case of light color gradient deep. This product is dissolved in dimethylformamide, slightly soluble in acetone, very slightly soluble in ethanol, almost insoluble in water or chloroform.

Functions and uses

Nitrofurantoin is a synthetic antimicrobial, antibacterial spectrum is broad, the majority of Gram-positive bacteria and negative bacteria have antibacterial activity, such as Staphylococcus aureus, Escherichia coli, Staphylococcus aureus and Streptococcus pyogenes. Clinically used for sensitive bacteria caused by urinary tract infections, such as pyelonephritis, urinary tract infection, cystitis and prostatitis.

Pharmacology

Pharmacodynamics: Nitrofurantoin mechanism of action is not very clear, and may interfere with bacterial enzymes, leading to bacterial metabolic disorders. Depending on the concentration, nitrofurantoin can be bacteriostatic or bactericidal.

Pharmacokinetics: Nitrofurantoin microcrystalline in the small intestine absorbed quickly and completely while the absorption of large crystalline is slow and causing a strong gastrointestinal irritation. Serum concentration of drugs is very low, high concentrations appear in the urine, the drug concentration in the kidney may also be higher. The goods can also enter the fetal circulation through the placenta. Protein binding rate of 60%, part of the body for the organization (including the liver) inactivation, T1 / 2 0.3 ~ l hours. Glomerular filtration as the main excretion pathway, a small amount of renal tubular secretion and reabsorption. 30 ~ 40% rapidly from the urine from the prototype, the excretion of large crystalline type more steamed.

Indications

1, nitrofurantoin should be served with food to reduce gastrointestinal irritation.

2, the course of treatment should be at least 7 days, or continue to medication to clear the urine more than 3 days.

3, long-term use of the goods in June or more, there was diffuse interstitial pneumonia or pulmonary fibrosis may be closely observed, early detection and timely withdrawal. So the goods for long-term prevention of the application need to weigh the pros and cons.

4, glucose-6-phosphate dehydrogenase deficiency, peripheral neuropathy, lung disease patients with caution.

5, the laboratory indicators of interference: the goods can interfere with urinary glucose determination, because of its metabolites in the urine of copper sulfate reagent can be a false positive reaction. 1 month of newborns disabled.

6, due to nitrofurantoin through the placental barrier, and fetal enzyme system has not yet fully developed, so pregnant women should not be applied late pregnancy, full-term pregnant women disabled to avoid fetal hemolytic anemia may occur.

7, a small amount of nitrofurantoin can enter the milk, induced infant hemolytic anemia, especially glucose-6-phosphate dehydrogenase deficiency, taking the goods should stop breast-feeding. Elderly patients should be used with caution, and should adjust the dose according to renal function.

Adverse reactions

(1) The more common are: chest pain, chills, cough, fever, difficulty breathing (pneumonia).

(2) less common are: dizziness, drowsiness, headache (nerve toxicity), facial or oral numbness, tingling or burning sensation, pale skin (hemolytic anemia), abnormal fatigue or weakness (neurotoxicity, polyneuropathy, hemolysis Anemia); skin, sclera yellow dye (hepatitis).

Leukopenia. It can cause gastrointestinal reactions: nausea, vomiting, loss of appetite, bloating, diarrhea. Postprandial use can reduce the reaction. Can also occur allergic skin rash, drug fever, chest tightness, asthma, shock. Peripheral neuritis, auditory hallucinations and hallucinations. Individual cases can cause liver and kidney damage. Liver dysfunction with caution. Can cause changes in blood and hemolytic anemia.

Interaction

1, can lead to hemolytic drugs and nitrofurantoin combination, there is the possibility of increased hemolytic reaction.

2, combined with hepatotoxic drugs have increased the possibility of liver toxicity; with neurotoxic drugs in combination, there may increase the neurotoxicity.

3, probenecid and benzenesulfonadol can inhibit nitrofurantoin secretion, resulting in the latter's plasma concentration increased and (or) serum half-life extended, while the urine concentration is reduced, the effect is also weakened, probenecid, etc. Of the dose should be adjusted.