• 대한장애인치과학회지
• /
• 제2권2호
• /
• pp.142-146
• /
• 2006

환아의 연령, 과다체중, 환아의 약물 거부 등으로 인하여 chloral hydrate를 이용한 수면치료가 불가능한 경우, Midazolam을 이용한 정주진정요법이 전신마취를 대신하는 대안으로 사용될 수 있다. 본 환아의 경우, 0.3mg/kg의 midazolam을 근주하고, 70% 아산화질소 가스를 이용하여 초기 수면상태를 유도하고 정맥천자를 실시한 후, 0.2mg/kg midazolam을 정주하여 50분간 별다른 부작용 없이 성공적으로 치료할 수 있었다.

• Biomolecules & Therapeutics
• /
• 제19권2호
• /
• pp.237-242
• /
• 2011

This study was designed to investigate the effects of glipizide on the pharmacokinetics of carvedilol after oral or intravenous administration of carvedilol in rats. Clinically carvedilol and glipizide can be prescribed for treatment of cardiovascular diseases as the complications of diabetes, and then, Carvedilol and glipizide are all substrates of CYP2C9 enzymes. Carvedilol was administered orally or intravenously without or with oral administration of glipizide to rats. The effects of glipizide on cytochrome P450(CYP) 2C9 activity and P-gp activity were also evaluated. Glipizide inhibited CYP2C9 activity in a concentration-dependent manner with 50% inhibition concentration ($IC_{50}$) of 18 ${\mu}M$. Compared with the control group, the area under the plasma concentration-time curve (AUC) was significantly increased by 33.0%, and the peak concentration ($C_{max}$) was significantly increased by 50.0% in the presence of glipizide after oral administration of carvedilol. Consequently, the relative bioavailability (R.B.) of carvedilol was increased by 1.13- to 1.33-fold and the absolute bioavailability (A.B.) of carvedilol in the presence of glipizide was increased by 36.8%. After intravenous administration, compared to the control, glipizide could not significantly change the pharmacokinetic parameters of carvedilol. Therefore, the enhanced oral bioavailability of carvedilol may mainly result from inhibition of CYP2C9-mediated metabolism rather than both P-gp-mediated effl ux in the intestinal or in the liver and renal elimination of carvedilol by glipizide.

• 대한수의학회지
• /
• 제7권2호
• /
• pp.51-55
• /
• 1967

The mammary excretion of suphamethomidine after intravenous and/or oral administration was investigated in cow. The results show that sulphamethomidine is bound to plasma proteins to a great extent (80~90%). Ay a dosage of 60 mg./kg. maximal concenration in plasma of this sulphonamide was reached 7-10 hours after oral dosing. The sulphonamide concentration in plasma slowly declined after both oral and intravenous administration (fig. 1, 2, and 3) The concentration of sulphonamide in milk was very low and the excretion was completed in 7 days after a single oral dose and 5 days after intravenous injection while in the case of blood plasma it was 11 and 7 days, respectively. In addition, the renal excretion of sulphamethomidine was investigated while under continuous intravenous intravenous infusion. The excretion ratios varies according to self depression (table. 1). Blockade of the tubular secretion with diodone lowered the excretion of sulphamethomidine. It is concluded that the renal excretion of sulphamethomidine in cows occurs by filtration by slight tubular secretion and also by a high rate of back diffusion.

• 대한수의학회지
• /
• 제36권1호
• /
• pp.221-233
• /
• 1996

This experiment was carried out to study the toxic effect of solublized methylcellulose (MC). Sprague-Dawley rats were dosed with 1%(w/v) MC in 0.9% saline by gavage at a dose of 10ml/kg b.w/day or by intravenous injection at a dose of 5ml/kg b.w/day for 28 days. Clinical signs were observed once a day. Body weights, water and food consumptions were measured and urinalysis was performed several times during the experiment. Rats were sacrificed on days 3, 7, 15 and 28 for hematology, blood chemistry, organ weights and histopathology. The relative weight of the spleen and foamy cells of the spleen were increased in the gavage group. Body weight gain, food consumptions, the values of RBC, Hb, MCH, Hct, serum proteins, glucose, bilirubin, AST, and ALP were decreased in I.V. treatment group. On the other hand, water consumptions, the values of serum cholesterol, creatinine, and BUN were increased. Microscopic findings were granulomas, distended sinusoids, and hypertrophy of Kupffer cells with vacuoles in the liver. Spleen exhibited granuloma, increased extramedullary hematopoiesis, and congestion. Kidney exhibited foamy cells in the glomeruli, distension of the tubules. The findings appeared more severe when the treatment was extended. In conclusion, MC solution is not a safe vehicle for intravenous administration because of the toxic effects on the liver, kidney and spleen. In addition, a long-term and large dosage of oral administration of MC appears to be unsafe also and needs to be investigated further.

• Biomolecules & Therapeutics
• /
• 제17권2호
• /
• pp.205-210
• /
• 2009

The present study investigated the effects of hydrocortisone on the pharmacokinetics of loratadine in rats after intravenous and oral administration. A single dose of loratadine was administered either orally (4 mg/kg) or intravenously (1 mg/kg) with or without oral hydrocortisone (0.3 or 1.0 mg/kg). Compared to the control group (without hydrocortisone), after oral administration of loratadine, the area under the plasma concentration-time curve (AUC) was significantly increased by 30.2-81.7% in the presence of hydrocortisone (p<0.05). The peak plasma concentration ($C_{max}$) was significantly increased by 68.4% in the presence of 1.0 mg/kg hydrocortisone after oral administration of loratadine (p<0.05). Hydrocortisone (1.0 mg/kg) significantly increased the terminal plasma half-life ($t_{1/2}$) of loratadine by 20.8% (p<0.05). Consequently, the relative bioavailability of loratadine was increased by 1.30- to 1.82-fold. In contrast, oral hydrocortisone had no effects on any pharmacokinetic parameters of loratadine given intravenously. This suggests that hydrocortisone may improve the oral bioavailability of loratadine by reducing first-pass metabolism of loratadine, most likely mediated by P-gp and/or CYP3A4 in the intestine and/or liver. In conclusion, hydrocortisone significantly enhanced the bioavailability of orally administered loratadine in rats, which may have been due to inhibition of both CYP 3A4-mediated metabolism and P-gp in the intestine and/or liver by the presence of hydrocortisone.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제31권4호
• /
• pp.300-305
• /
• 2005

Purpose: For the reconstruction of maxillofacial defect created by trauma, infection, or tumor etc, the role of microvascular anastomosis or vessel graft has been increased. Many methods has been tried to increase the success rate of microvascular anastomosis. Various anticoagulants and thrombolytic agents have been used to reduce the failure rate of microvascular anastomosis and avoid re-operation. Many drugs, however, have been used in the limited cases because most of these drugs may cause complications, such as allergy, fever or systemic bleeding. This study was performed to evaluate the influence of the Argatroban on patency and thrombosis in microvascular anastomosis when it is used for local irrigation or general administration. Materials & methods: Eight mature rabbits, weighing 2kg, were used. After exposing both femoral veins, the artificial thrombotic model was made by crushing injury using a smooth needle holder, and the transverse incision were made on femoral vein. The animals were divided into 4 groups according to Argatroban administration methods; control group (n=4), topical irrigation of lumen with saline solution; experimental group 1 (n=4), topical irrigation of lumen with Argatroban saline solution; experimental group 2 (n=4), topical irrigation of lumen with heparin followed by intravenous injection of Argatroban; experimental group 3 (n=4), topical irrigation of lumen with Argatroban followed by IV of Argatroban. Microvascular anastomosis was done with 10-0 Ethilon. The patency was evaluated by empty-and-refill test 30 minutes and 3 days after microanastomosis. The thrombus formation was examined 3 days after microanastomosis by surgical microscope. The histologic findings were also examined. Results: 1. Thirty minutes after microvascular anastomosis, the patency of all experimental groups was better than that of control group, but there was no significant difference among groups. 2. Three days after microvascular anastomosis, the patency of all experimental groups was more improved than that of control group (p<0.05). There was no significant difference among experimental groups. 3. Three days after microvascular anastomosis, the amount of thrombus in all experimental groups was less than that of control group (p<0.05). There was no significant difference among experimental groups. 4. Histologically, a lot of luminal thrombus was observed around sutured area in control group. Few luminal thrombus was observed in all experimental groups. The necrotic changes were observed on the sutured vein wall in all specimens. Conclusion: These results indicate that topical irrigation and/or intravenous administration of Argatroban is effective in improving patency and preventing thrombus formation after microvascular anastomosis.

• Biomolecules & Therapeutics
• /
• 제18권2호
• /
• pp.226-232
• /
• 2010

The aim of this study was to investigate the effect of atrovasatatin on the pharmacokinetics of nicardipine after oral and intravenous administration of nicardipine to rats. Nicardipine was administered orally (12 mg/kg) or intravenously (i.v., 4 mg/kg) without or with oral administration of atrovasatatin (0.3 or 1.0 mg/kg) to rats. The effect of atorvastatin on the P-glycoprotein (P-gp) as well as CYP3A4 activity was also evaluated. Atorvastatin inhibited CYP3A4 enzyme activity in a concentration-dependent manner with 50% inhibition concentration ($IC_{50}$) of 48 ${\mu}M$. Compared to the controls (nicardipine alone), the area under the plasma concentration-time curve (AUC) of nicardipine was significantly (1.0 mg/kg, p<0.05) greater by 16.8-45.4%, and the peak plasma concentration ($C_{max}$) was significantly (1.0 mg/kg, p<0.05) higher by 28.0% after oral administration of nicardipine with atorvastatin, respectively. Consequently, the relative bioavailability (R.B.) of nicardipine was increased by 1.17- to 1.45-fold and the absolute bioavailability (A.B.) of nicardipine with atrovasatatin was significantly greater by 16.7-20.9% compared to that of the controls (14.3%). Compared to the i.v. control, atrovasatatin did not significantly change pharmacokinetic parameters of i.v. administration nicardipine. The enhanced oral bioavailability of nicardipine by atorvastatin suggests that CYP3A subfamily-mediated metabolism were inhibited in the intestine and/or in the liver rather than P-gp-mediated efflux of nicardipine. Based on these results, modification of nicardipine of dosage regimen is required in the patients. Human studies are required to prove the above hypothesis.

• Biomolecules & Therapeutics
• /
• 제19권4호
• /
• pp.493-497
• /
• 2011

The aim of this study was to investigate the effect of amlodipine on the pharmacokinetics of warfarin after oral and intravenous administration of warfarin in rats. Warfarin was administered orally (0.2 mg/kg) or intravenously (0.05 mg/kg) without or with oral administration of amlodipine (0.1 or 0.4 mg/kg) in rats. The effect of amlodipine on the P-glycoprotein (P-gp) as well as cytochrome P450 (CYP) 3A4 activity was also evaluated. Amlodipine inhibited CYP3A4 enzyme activity with 50% inhibition concentration ($IC_{50}$) of 9.1 ${\mu}M$. Compared to those animals in the oral control group (warfarin without amlodipine), the area under the plasma concentration-time curve (AUC) of warfarin was significantly greater (0.1 mg/kg, p<0.05; 0.4 mg/kg, p<0.01) by 26.5-53.5%, and the peak plasma concentration ($C_{max}$) was significantly higher (0.4 mg/kg, p<0.05) by 26.2% after oral administration of warfarin with amlodipine, respectively. Consequently, the relative bioavailability of warfarin increased by 1.26- to 1.53-fold and the absolute bioavailability of warfarin with amlodipine was significantly greater by 61.7-72.5% compared to that in the control group (47.4%). In contrast, amlodipine had no effect on any pharmacokinetic parameters of warfarin given intravenously. Therefore, the enhanced oral bioavailability of warfarin may be due to inhibition of CYP 3A4-mediated metabolism in the intestine and/or liver rather than renal elimination and P-gp by amlodipine.

• Journal of Dental Anesthesia and Pain Medicine
• /
• 제16권3호
• /
• pp.165-173
• /
• 2016

Dentists often sedate patients in order to reduce their dental phobia and stress during dental treatment. Sedatives are administered through various routes such as oral, inhalation, and intravenous routes. Intravenous administration has the advantage of rapid onset of action, predictable duration of action, and easy titration. Typically, midazolam, propofol or dexmedetomidine are used as intravenous sedatives. Administration of these sedatives via infusion by using a syringe pump is more effective and successful than infusing them as a bolus. However, during intravenous infusion of sedatives or opioids using a syringe pump, fatal accidents may occur due to the clinician's carelessness. To prevent such risks, smart syringe pumps have been introduced clinically. They allow clinicians to perform effective sedation by using a computer to control the dose of the drug being infused. To ensure patient safety, various alarm features along with a drug library, which provides drug information and prevents excessive infusion by limiting the dose, have been added to smart pumps. In addition, programmed infusion systems and target-controlled infusion systems have also been developed to enable effective administration of sedatives. Patient-controlled infusion, which allows a patient to control his/her level of sedation through self-infusion, has also been developed. Safer and more successful sedation may be achieved by fully utilizing these new features of the smart pump.

• Biomolecules & Therapeutics
• /
• 제21권2호
• /
• pp.170-172
• /
• 2013

The pyrimidine nucleoside uridine has recently been reported to have a protective effect on cultured human corneal epithelial cells, in an animal model of dry eye and in patients. In this study, we investigate the pharmacokinetic profile of uridine in rabbits, following topical ocular (8 mg/eye), oral (450 mg/kg) and intravenous (100 mg/kg) administration. Blood and urine samples were serially taken, and uridine was measured by high-performance liquid chromatography-tandem mass spectrometry. No symptoms were noted in the animals after uridine treatment. Uridine was not detected in either plasma or urine after topical ocular administration, indicating no systemic exposure to uridine with this treatment route. Following a single intravenous dose, the plasma concentration of uridine showed a bi-exponential decay, with a rapid decline over 10 min, followed by a slow decay with a terminal half-life of $0.36{\pm}0.05$ h. Clearance and volume of distribution were $1.8{\pm}0.6$ L/h/kg and $0.58{\pm}0.32$ L/kg, respectively. The area under the plasma concentration-time curves (AUC) was $59.7{\pm}18.2{\mu}g{\cdot}hr/ml$, and urinary excretion up to 12 hr was ~7.7% of the dose. Plasma uridine reached a peak of $25.8{\pm}4.1{\mu}g/ml$ at $2.3{\pm}0.8$ hr after oral administration. The AUC was $79.0{\pm}13.9{\mu}g{\cdot}hr/ml$, representing ~29.4% of absolute bioavailability. About 1% of the oral dose was excreted in the urine. These results should prove useful in the design of future clinical and nonclinical studies conducted with uridine.