Vincamine

/LABORATORY ANIMALS: Acute Exposure/ Vincamine was administered to gerbils at doses of 0, 1, 2, 10 and 40 mg/kg/day to study its effect on survival, extent of ischemic brain lesion, locomotor activity, neurologic signs, stool production, and food and water intake after unilateral carotid occlusion. Drug and placebo were delivered by implantation of osmotic minipumps. The three most important criteria, increase in survival, reduction in cerebral lesion in survivors, and functional recovery of locomotor activity were all significantly improved by vincamine treatment at all doses. Since the lowest dose produced as much improvement as the higher doses it was concluded that increasing dose beyond 1 mg/kg/day was not beneficial using the measures reported here.

/LABORATORY ANIMALS: Acute Exposure/ Mouse liver was examined following a single intraperitoneal application of 25 mg/kg body weight vincamine. The studies were made using the technique of thin-sectioning for electron microscopy as well as the freeze-fracture method. In contrast to the control animals the tight junctions in the liver tissue of mice treated with vincamine were disorganized and irregularly arranged. The gap junctions showed a very irregular contour as well.

/LABORATORY ANIMALS: Acute Exposure/ ...Vincamine and its analogues are markedly effective for treating cyanide /toxicity in mice/.

/LABORATORY ANIMALS: Acute Exposure/ In dogs, cats and rabbits the sedative effect only appeared at sublethal doses (100 times the one of reserpine).

For more Non-Human Toxicity Excerpts (Complete) data for VINCAMINE (12 total), please visit the HSDB record page.

Basic treatment: Establish a patent airway. Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations if needed. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for pulmonary edema and treat if necessary ... . Monitor for shock and treat if necessary ... . Anticipate seizures and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with normal saline during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 ml/kg up to 200 ml of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool ... . Cover skin burns with dry sterile dressings after decontamination ... . /Poison A and B/

Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in respiratory arrest. Positive pressure ventilation techniques with a bag valve mask device may be beneficial. Monitor cardiac rhythm and treat arrhythmias as necessary ... . Start an IV with D5W /SRP: "To keep open", minimal flow rate/. Use lactated Ringer's if signs of hypovolemia are present. Watch for signs of fluid overload. Consider drug therapy for pulmonary edema ... . For hypotension with signs of hypovolemia, administer fluid cautiously. Watch for signs of fluid overload ... . Treat seizures with diazepam (Valium) ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Poison A and B/

Presentation depends on the active toxic agent. In most cases, vomiting, abdominal pain, and diarrhea occur within 60 to 90 minutes of significant ingestion. With some toxins, severe gastroenteritis may result in massive fluid and electrolyte loss. ... Maintain open airway and assist ventilation if necessary. Administer supplemental oxygen. Treat coma, seizures, arrhythmias, and hypotension if they occur. Replace fluid loss caused by gastroenteritis with intravenous crystalloid solutions. ... Administer activated charcoal if available ... Gastric emptying is not necessary if activated charcoal is given promptly. /Plants and Herbal Medicines: Group 1/

LD50 Mouse iv 75 mg/kg

LD50 Mouse sc >1,000 mg/kg

LD50 Mouse oral 1,000 mg/kg

LD50 Rat ip 253 mg/kg

For more Non-Human Toxicity Values (Complete) data for VINCAMINE (6 total), please visit the HSDB record page.

The metabolism of vincamine hydrochloride was studied in the rat after oral administration of the drug. Vincamine is almost completely metabolized, only a small fraction of the original compound being excreted in the urine. The metabolites detected in blood, urine and tissues were purified by preparative thin layer and column chromatography in several solvent systems, and analyzed by mass spectrometry. It was found that the main urinary metabolites were vincamine conjugates (sulphates and glucuronides). Two new metabolites were detected in all the biological fluids and specimens analyzed: these compounds are more polar than vincamine and their structure was characterized by mass spectrometry, I.R. and U.V. spectroscopy and confirmed by synthesis in our laboratory.[Vigano V et al; Farmaco

Vincamine is very extensively metabolised with only a small percentage of unchanged compound detectable in the urine. Radiolabel studies in rats after an oral dose of 10 mg/kg bw demonstrate the metabolic pathway of vincamine. On the one hand it is hydrolysed by the plasma esterases to the unstable vincaminic acid. The latter is quickly decarboxylised and oxidised to eburnamenine. On the other hand vincamine is hydroxylated to the major metabolite 6-beta-hydroxy-vincamine, which accounts for 40% of total urinary and biliary radioactivity, followed by 6-alpha-hydroxy-vtncamine (8%) and 6-keto-vincamine, the oxidized metabolite of both previous metabolites (about 10% of the administered dose). 6-Keto-vincamine is eliminated by conjugation. The same metabolites (hydroxy.-keto) could also be detected in the urine of rabbits, dogs and man. Within 72 hours 40% of the total radioactivity are excreted in twine and 23% in the feces.

Drugs used in the treatment of acute or chronic vascular HYPERTENSION regardless of pharmacological mechanism. Among the antihypertensive agents are DIURETICS; (especially DIURETICS, THIAZIDE); ADRENERGIC BETA-ANTAGONISTS; ADRENERGIC ALPHA-ANTAGONISTS; ANGIOTENSIN-CONVERTING ENZYME INHIBITORS; CALCIUM CHANNEL BLOCKERS; GANGLIONIC BLOCKERS; and VASODILATOR AGENTS.

Drugs used to cause dilation of the blood vessels.

In a crossover study of six healthy volunteers the pharmacokinetics and the bioavailability of vincamine were studied after administration of two oral forms. All subjects received an oral dose of 60 mg vincamine. ...The drug generally follows a one-compartment kinetic model. The average value of Tmax is 1.4 +/- 0.5/hr with the tablets and 1 +/- 0.6/hr with the solution; the Cmax are, respectively, 155 +/- 82 micrograms . 1(-1) and 133 +/- 104 micrograms . 1(-1). The AUC are 443 +/- 156 micrograms . 1(-1) hr with the tablets and 315 +/- 178 micrograms . 1(-1) hr with the solution.

Vincamine HCl was biopharmaceutically and pharmacokinetically evaluated. For biopharmaceutical characterization of the drug the apparent lipoid/water partition coefficient (APC), pKa, extent of protein (bovine) binding and the erythrocyte (human) uptake were determined. Vincamine has an APC of 2.05, a pKa of 6.17, is 64% bound to plasma proteins, and is about 6% bound to erythrocytes. Because the gerbil was used as model in pharmacodynamic studies, the pharmacokinetic drug disposition was determined in this species and compared to parameters reported in the literature for other species. The terminal half-life is about 1 hour, the apparent volume of distribution 2.9 L/kg, and the total clearance is about 33.3 mL/min/kg. The parameters are comparable to other species including man. The brain concentration is about 5-fold that in plasma. A therapeutic steady state concentration for effectiveness in gerbils has been estimated to be 0.02 ug/mL.

Pharmacokinetic parameters of vincamine in rats were measured after oral administration of 20 mg base/kg bw and intravenous injection of 10 mg vincamine hydrochloride/kg bw. After oral administration, a bioavailability of 58% was found and the concentration/time curve showed a two-compartment open model. The following parameters were observed: an elimination half-life of 1.71 hours, a t-max of 1.27 hours, a C-max of 0.87 ug/ml, a total clearance of 0.818 1/h (higher than the plasma perfusion volume, which indicates a very quick metabolism in other organs in addition to the liver), and a volume of distribution of 2.018 liters. The amount of unchanged vincamine excreted was very low with 3 to 11% in urine and 2 to 5% in bile. Vincamine is taken up in high concentrations into the different organs resulting in the following ratios: lung/plasma 21, brain/plasma 14.6, kidneys/plasma 14.3, liver/plasma 8.9, heart/plasma 7.6. However, elimination from these organs was significantly more rapid than from plasma. After intravenous injection the pharmacokinetic parameters observed were an elimination half-life of 1.68 hours, a C-max of 5.46 ug/ml, a total clearance of 0.866 1/hour, and a volume of distribution of 2.104 liters. The values for elimination half-life, volume of distribution and total clearance did not differ significantly between oral and intravenous administration.

Pharmacokinetics of vincamine in dogs also followed a two-compartment open model. Doses of 10, 20 and 40 mg intravenously showed dose-dependent half-life and clearance rate. After oral administration of 20 mg vincamine hydrochloride, bioavailability ranged between 23 and 58%. Vincamine could be detected in the urine at up to 9.5% depending on urinary pH.

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