Mortality Due to Hyperglycemic Crises in the US, 1999-2022.

This study analyzes trends in US mortality attributed to both diabetic ketoacidosis and hyperosmolar hyperglycemic state from 1999-2022.

Comparison of Recurrent Laryngeal Nerve Insult Incidence Post Thyroidectomy for Benign and Malignant Lesions.

Background: Vocal cord paresis or paralysis caused by insult to the recurrent laryngeal nerve is one of the main hazards in thyroid surgery. The frequency of recurrent laryngeal nerve palsy varies between 1.5-20%. Hoarseness is found with unilateral recurrent laryngeal nerve insult (RLNI). Bilateral insult produces dyspnea and life-threatening glottal obstruction. The frequency of insult is more in re-do surgeries, Graves' disease, and thyroid carcinoma operations. Objective: This study aimed to evaluate the risk factors of RLNI in thyroid surgery for benign or malignant lesions. Methods: This retrospective investigation recruited 255 participants of both genders, aged 21-59 yrs. (average 39 yrs.), who were scheduled for thyroid surgery at King Hussein Hospital, King Hussein Medical City, Amman, Jordan, from October 2019 to October 2022. An indirect laryngoscopic examination was done for all participants pre and post surgery. Factors of RLNI such as benign or malignant lesions and type of surgery were investigated. Significance was tested with the chi-square test. A P-value of < 0.05 was considered significant. Results: RLNI was recorded in 25/255 patients (9.8%) following thyroidectomy. Temporary unilateral vocal cord insult was recorded in 17/255 (6.7%) participants out of which it became permanent for 3/255 (1.2%) participants. Bilateral vocal cord insult was recorded in 8/255 (3.1%) participants but did not become permanent for any of them (P < 0.05). A remarkable increase in the frequency of RLNI was found in total/near-total thyroidectomy patients (7/27, 25.9%) compared to patients with bilateral or unilateral subtotal thyroidectomy(18/228, 7.9%; P < 0.05), in malignant lesions (18/105, 17.1%) compared to in benign lesions(7/150, 4.7%; P < 0.05), and in men (9/74, 12.2%) compared to in women(16/181, 8.8%; P < 0.05). Conclusion: Thyroid carcinoma, total thyroidectomy, and male sex were correlated with a remarkable risk of surgical RLNI.

The delaying of elective surgeries after COVID-19 infection decreases postoperative complications.

BACKGROUND: Huge controversy surrounds delaying elective surgeries after COVID-19 infection. Although two studies evaluated the issue, several gaps still exist. METHODS: A propensity score matched retrospective single center cohort design was used to evaluate the optimum time of delaying elective surgeries after COVID-19 infection and the validity of the current ASA guidelines in this regard. The exposure of interest was a previous COVID-19 infection. The primary composite included the incidence of death, unplanned Intensive Care Unit admission or postoperative mechanical ventilation. The secondary composite included the occurrence of pneumonia, acute respiratory distress, or venous thromboembolic. RESULTS: The total number of patients was 774, half of them had a history of COVID-19 infection. The analysis revealed that delaying surgeries for 4 weeks was associated with significant reduction in primary composite (AOR = 0.02; 95%CI: 0.00-0.33) and the length of hospital stay (B = 3.05; 95%CI: 0.41-5.70). Furthermore, before implementing the ASA guidelines in our hospital, a significant higher risk for the primary composite (AOR = 15.15; 95%CI: 1.84-124.44; P-value = 0.011) was observed compared to after applying it. CONCLUSION: Our study showed that the optimum period of delaying elective surgery after COVID-19 infection is four weeks, with no further benefits from waiting for longer times. This finding provide further support to the current ASA guidelines about delaying elective surgeries. Further large-scale prospective studies are needed to give more evidence-based support to the appropriateness of the 4-week waiting time for elective surgeries after COVID-19 infection and to investigate the effect of type of surgery on the required delay.

Significance of Statin-Associated Muscle Symptoms and Its Impact on Patients Adherence and Outcomes.

ABSTRACT: Statin-associated muscle symptoms (SAMS) are one of the most common side effects of statins. This study aimed to explore the significance of SAMS among statin users by comparing statin users with a control group. To achieve our aims, a propensity score matching the retrospective cohort study was conducted in a single center tertiary hospital. The statin muscle symptoms were assessed using the Proposed Statin Myalgia Index Score, whereas the patient's adherence to medications was evaluated using the Morisky Medication Adherence Scale-8. We included 743 patients in our study; of them, 64.9% were on statin, whereas the rest were controls (35.1%). After propensity score matching, patients on statin had significantly higher rates of SAMS (5.0%) compared with control (1.6%) (AOR = 3.209; 95% CI: 1.020-10.091). However, there was no significant difference between statin users and controls in medications nonadherence ( P -value = 0.820). Our analysis among statins users revealed that moderate-intensity (2.671; 95% CI: 1.691-3.310) and high-intensity (3.552; 95% CI: 2.190-4.129) statin therapy was significantly associated with SAMS. In addition, autoimmune diseases were significantly associated with SAMS occurrence (AOR = 32.301; 95% CI: 1.785-584.374). Also, patients on PPIs had significantly less occurrence of SAMS (AOR = 0.145; 95% CI: 0.044-0.483), whereas patients on antiepileptic drugs had significantly higher SAMS occurrence (AOR = 72.337; 95% CI: 2.649-1975.201). Regarding MACE among statin users, there was no significant difference in the 1-year or 5-year MACE rate between statin users and controls. Our study suggests that SAMS are significant among statin users and must be addressed by health care providers to ensure that patients are still adherent to their medications and hence protected against cardiac events.

Perinatal risk factors for infantile hypertrophic pyloric stenosis: A systematic review and meta-analysis.

BACKGROUND: Infantile hypertrophic pyloric stenosis (IHPS) is one of the most common diseases that require surgical intervention amongst the paediatric population. Although the treatment and the diagnosis of pyloric stenosis are well established, the perinatal risk factors associated with it still need further investigation. METHODS: We searched the following databases: Cochrane, Google Scholar, PubMed, and Scopus. Studies were included if they were case-control or cohort in design and studied the perinatal risk factors associated with IHPS. The quality of the included studies was assessed using the Newcastle-Ottawa scale (NOS). RESULTS: Twenty-one articles were included in this meta-analysis, including 18,104,753 participants. Our analysis showed a significant association between IHPS and male sex (RR=2.71, 95% CI:1.93-3.78), maternal smoking (RR=1.75, 95% CI: 1.54 - 2.00), bottle-feeding (RR=1.68, 95% CI: 1.42 - 1.98), being first born (RR=1.23, 95% CI:1.07-1.40), African ethnicity (RR=0.51, 95% CI: 0.35-0.75), and cesarean section (RR=1.57, 95% CI: 1.49-1.66). On the contrary, there was no significant association between IHPS and multiple gestations, preterm labour, being born in summer, and small for gestational age (SGA). CONCLUSION: In conclusion, our analysis showed that male sex, bottle feeding, maternal smoking and African ethnicity were significantly associated with the risk of IHPS. However, most of the included articles were retrospective in design which necessitates conducting future prospective well-designed studies to further investigate the risk factors of IHPS.

Efficacy and safety of COVID-19 vaccines: A network meta-analysis.

OBJECTIVE: Several vaccines showed a good safety profile and significant efficacy against COVID-19. Moreover, in the absence of direct head to head comparison between COVID-19 vaccines, a network meta-analysis that indirectly compares between them is needed. METHODS: Databases PubMed, CENTRAL, medRxiv, and clinicaltrials.gov were searched. Studies were included if they were placebo-controlled clinical trials and reported the safety profile and/or effectiveness of COVID-19 vaccines. The quality of the included studies was assessed using the Revised Cochrane risk-of-bias tool for randomized trials and the Revised Cochrane risk-of-bias tool for nonrandomized trials. RESULTS: Forty-nine clinical trials that included 421,173 participants and assessed 28 vaccines were included in this network meta-analysis. The network meta-analysis showed that Pfizer is the most effective in preventing COVID-19 infection whereas the Sputnik Vaccine was the most effective in preventing severe COVID-19 infection. In terms of the local and systemic side, the Sinopharm and V-01 vaccines were the safest. CONCLUSION: We found that almost all of the vaccines included in this study crossed the threshold of 50% efficacy. However, some of them did not reach the previously mentioned threshold against the B.1.351 variant while the remainder have not yet investigated vaccine efficacy against this variant. Since each vaccine has its own strong and weak points, we strongly advocate continued vaccination efforts in individualized manner that recommend the best vaccine for each group in the community which is abundantly required to save lives and to avert the emergence of future variants.

Safety and Efficacy of SSRIs in Improving Poststroke Recovery: A Systematic Review and Meta-Analysis.

Background Several studies investigated the role of selective serotonin reuptake inhibitors (SSRIs) in improving poststroke recovery; thus, we have decided to conduct this systematic review and meta-analysis to investigate the efficacy and safety of SSRIs in poststroke recovery. Methods and Results In this meta-analysis we searched the following databases: PubMed, Cochrane, Scopus, and Google Scholar. The studies were included if they were placebo-controlled trials in design and reported SSRIs' effects on poststroke depression, anxiety, disability, dependence, motor abilities, and cognitive functions. The quality of the included studies was assessed using the revised Cochrane risk-of-bias tool for randomized trials. The search yielded 44 articles that included 16 164 patients, and about half of the participants were treated with SSRIs. Our results showed that SSRIs had a significant effect on preventing depression (weighted mean difference [WMD], -7.05 [95% CI, -11.78 to -2.31]), treating depression according to the Hamilton Rating Scale for Depression score (WMD, -1.45 [95% CI, -2.77 to -0.14]), anxiety (relative risk, 0.23 [95% CI, 0.09-0.61]), dependence (WMD, 8.86 [95% CI, 1.23-16.48]), motor abilities according to National Institutes of Health Stroke Scale score (WMD, -0.79 [95% CI, -1.42 to -0.15]), and cognitive functions (WMD, 1.00 [95% CI, 0.12-1.89]). On the other hand, no significant effect of SSRIs on disability was observed. Additionally, we found that treating with SSRIs increased the risk of seizures (relative risk, 1.44 [95% CI, 1.13-1.83]), whereas there was no difference in the incidence of gastrointestinal symptoms or bleeding between SSRIs and a placebo. Conclusions Our study showed that SSRIs are effective in preventing and treating depression, and improving anxiety, motor function, cognitive function, and dependence in patients after stroke. These benefits were only reproducible with the citalopram subanalysis but not fluoxetine. Further well-conducted placebo-controlled trials are needed to investigate the safety and efficacy of citalopram among patients after stroke. Registration URL: www.crd.york.ac.uk/prospero/; Unique identifier: CRD42021285766.

An ultrashort video can teach residents to perform a fingertip injury repair.

BACKGROUND: Acute fingertip injuries are common. Providers in rural and underserved areas often transfer these patients due to lack of comfort and skill with treating these injuries. Current learners prefer short and high-density educational material. It is unknown if basic hand procedures can be taught using ultrashort training videos. This study investigates whether fingertip repair can be taught using a 60-second educational video viewed immediately prior to performing the procedure. METHODS: A standardized cadaveric fingertip injury model was developed. Twenty-three emergency medicine residents each having minimal experience with fingertip injury repair were randomized into one of three study arms: A) no video, B) standard-length (8-minute) video, and C) ultrashort (60-second) video. Each subject was presented with an injured cadaveric finger and asked to prepare for and perform the repair within a 30-minute time frame. The repair was graded on a 10-point scale following a standard rubric. Time to completion, preparedness, and subjects' confidence were also assessed. Results were analyzed by one-way ANOVA and Kruskal-Wallis tests. RESULTS: Mean repair scores for the standard-length video group (9.5 ± 0.3) and the ultrashort video group (9.2 ± 0.3) were significantly higher than those of the no video group (4.0 ± 0.3, p < 0.05 for both comparisons). Mean time to completion of the exercise was significantly shorter in the ultrashort video group (19 ± 2 minutes) than in the standard-length video group (26 ± 2 minutes). Subject-reported outcomes (median preparedness, median post-repair confidence, and median change in confidence following the procedure) were all significantly higher in the standard-length video group and the ultrashort video group than in the no video group (p < 0.05 for all comparisons). CONCLUSION: A 60-second educational video viewed immediately prior to performing a fingertip injury repair can effectively teach an emergency medicine resident to correctly perform the procedure.

Quality of Distance Learning After One and a Half Year From Its Integration Due to the COVID-19 Pandemic: A Cross-Sectional Study at the University of Jordan.

Background The coronavirus disease 2019 (COVID-19) pandemic mandated the change from face-to-face learning to distance learning. As a result, the quality of distance learning worldwide is questionable. Objectives and aims The aim of this study is to investigate the quality of distance learning among university students at the University of Jordan, as well as its determinants and obstacles. Methods A questionnaire-based cross-sectional study was conducted among undergraduate students at the University of Jordan from May 29 to July 11, 2021. Using a quantitative approach, students' attitudes toward and perceptions of online and distance education were analyzed. The Distance Education Learning Environments Survey (DELES) tool was used to evaluate the quality of distance learning during COVID-19 pandemic. IBM SPSS Version 25 was used for data analysis. Results The total number of participants was 486, and the mean total DELES score was 61.6 ± 24.6. The lowest mean of DELES score components was for the active learning component (6.9 ± 2.9). Moreover, 65.9% of the students were very dissatisfied or dissatisfied with the quality of distance learning. The quality of distance learning derived by the total DELES score was determined by several general demographics, and students' perceptions and attitudes. Conclusions The present study showed a low quality of distance learning and high levels of dissatisfaction among students at the University of Jordan. Thus, improvement of distance learning quality by filling its infrastructural defects and the implementation of its adjunct tools are required. In addition, we recommend collaboration with regional and international educational institutions to improve the quality of distance learning.

Effect of Dosage Reduction of Hypoglycemic Multidrug Regimens on the Incidences of Acute Glycemic Complications in People With Type 2 Diabetes Who Fast During Ramadan: A Randomized Controlled Trial.

Objective: We aimed to investigate the effect of dosage reduction of four hypoglycemic multidrug regimens on the incidences of acute glycemic complications in people with type 2 diabetes who fast during Ramadan. Methods: We conducted an open-label, parallel-group, randomized controlled trial at a tertiary care center in Amman, Jordan. We recruited adults with type 2 diabetes who expressed an intention to fast during Ramadan and were adherent to one of four regimens-namely: metformin and glimepiride; metformin and vildagliptin; metformin and insulin glargine U100; or, metformin, insulin glargine U100, and human regular insulin. We randomly assigned participants in a 2:1 ratio to low- or regular-dosage therapy. The primary outcomes were the incidences of hypoglycemia and hyperglycemia during the 29 days of Ramadan 2017, and the secondary outcomes were the incidences of diabetic ketoacidosis and hyperosmolar hyperglycemic state during the same period. Results: We randomly assigned 687 participants to low-dosage therapy (n = 458) or regular-dosage therapy (n = 229) and included 678 (452 and 226, respectively) in the final analysis. The incidence of hypoglycemia was lower in the low-dosage group compared with the regular-dosage group (19 [4.2%] vs. 52 [23.0%], respectively; OR, 0.15 [95% CI, 0.08-0.26]; P < 0.001). The incidence of hyperglycemia did not differ between the low- and regular-dosage groups (319 [70.6%] vs. 154 [68.1%], respectively; OR, 1.12 [95% CI, 0.79-1.58]; P = 0.5). No participants experienced diabetic ketoacidosis or hyperosmolar hyperglycemic state. Each 1% decrease in the baseline HbA1c concentration was associated with a 19.9-fold (95% CI, 9.6-41.5; P < 0.001) increase in the odds of hypoglycemia, and each 1% increase in the baseline HbA1c concentration was associated with a 15.7-fold (95% CI, 10.0-24.6; P < 0.001) increase in the odds of hyperglycemia. Conclusion: Dosage reduction decreases the incidence of hypoglycemia without a concomitant increase in the incidences of hyperglycemia, diabetic ketoacidosis, and hyperosmolar hyperglycemic state in people with type 2 diabetes who fast during Ramadan. Clinical Trial Registration: www.ClinicalTrials.gov, identifier NCT04237493.

Chitosan gel formulations containing egg yolk oil and epidermal growth factor for dermal burn treatment.

In the present study chitosan based gel formulations containing Egg Yolk Oil (EYO) and Epidermal Growth Factor (EGF) were formulated successfully aiming at enhanced topical treatment of dermal burns the combination of traditional approaches with modern drug delivery systems. Physicochemical properties of the formulations were analyzed and efficacy of the formulations prepared were evaluated versus a commercial product; Silverdin (1% silver sulfadiazine) in vivo on Wistar rats. Burns were generated on the back of the rats and at predetermined time intervals tissue samples were collected and evaluated histologically. The analyses showed that chitosan based gel formulations containing Egg Yolk Oil (E1) and chitosan based gel formulations containing EYO and EGF (M1) formulations seem to be better alternatives for Silverdin with a significant difference (p < 0.05) considering healing ranks of tissue samples.

Solid lipid and chitosan particulate systems for delivery of siRNA.

Due to the recent advances in molecular biology, there are promising gene therapy studies for prevention and treatment of cancer, genetic and infectious diseases. Many technologies in molecular biology and biotechnology were developed, and among those technologies, 'antisense technology' has become prominent in recent years. In this study, non-viral gene delivery systems such as solid lipid and chitosan nanoparticles were developed for improving intercellular delivery of siRNA. Commercially available Bcl-2 siRNA which is specific for Bcl-2 mRNA was used as a genetic material. Particle size, zeta potential, siRNA binding abilities and cytotoxic properties of the systems were evaluated and transfection assay was performed on among the prepared formulations. When the results of those studies were compared with Lipofectamine 2000, prepared formulations were found to show usable results. A novel method was developed in this study for producing solid lipid nanoparticles (SLNs) with highly efficient siRNA encapsulation. The results of this study showed that the genetic materials can be encapsulated in SLNs and SLNs have the potential to be used as a transfection agents.

Solid lipid nanoparticles: a possible vehicle for zinc oxide and octocrylene.

An efficient sunscreen formulation shows good absorption in the relevant UV range. Efficacy also means that the UV absorber must be easily incorporated in any kind of formulation. In this study, a chemical absorber, octocrylene, and one of the most important physical blockers, zinc oxide, could be successfully incorporated into Solid Lipid Nanoparticle (SLN) systems which themselves have UV blocking potential similar to physical sunscreens, and remained stable for a period of 360 days while providing UVA and UVB protection. Crystalline structure related to the chemical nature of the solid lipid is a key factor to decide whether a sunscreening agent will be expelled or incorporated in the long-term and for a controlled optimization of active ingredient incorporation and loading, intensive characterization of the physical state of the lipid particles was highly essential. Thus, FT-IR, NMR, XRD and DSC analyses were performed and the results did not indicate stability problems. pH values of the SLN systems were found to be between 5.4-5.9 in all formulations which may be buffered by the skin. Transpore test results proved the UV blocking potential of the SLNs with not any active ingredient and the synergistic effects by the incorporation of molecular sunscreens. Therefore, concentration of molecular sunscreens in the formulations was decreased to 0.6%. UVA and UVB screening potentials of octocrylene and zinc oxide formulations were compared in the 290-400 nm wavelength region. Zinc oxide loaded SLN suspensions were found to be more effective in the UVA region while octocrylene loaded ones performed better in the UVB region.

A validated HPLC method for the determination of octocrylene in solid lipid nanoparticle systems.

UV filters are traditionally classified as chemical absorbers and physical blockers depending on their mechanism of action. In this study, one of the most important chemical UVB absorber, octocrylene, was incorporated into Solid Lipid Nanoparticle (SLN) systems which themselves have UV blocking potential similar to physical blockers. Determination of octocrylene in the formulations was performed by HPLC (High Performance Liquid Chromatography) using a new validated method based on ICH harmonised tripartite guideline "validation of analytical procedures Q2(R1)". Determination and validation studies were carried out on a 4.6 x 250 mm, 5 microm C18 ACE column using an optimized mobile phase of acetonitrile:water (75:25, v/v) at a flow rate of 1.5 mL x min(-1). UV detection was performed at 210 nm and the column temperature was adjusted to 50 degrees C. Cyclosporine A was used as an internal standard (IS). The specified working range was derived from linearity studies and kept in the concentration range of 2.5 x -5.5 x 10(-5) M. Good correlation and accuracy were obtained. Limit of detection (LOD) and limit of quantitation (LOQ) values were determined to be 1.64 x 10(-6) M and 4.97 x 10-6 M, respectively. Octocrylene recovery % results of the SLN formulations stored at 25 degrees C, 4 degrees C and 40 degrees C for 360 days were investigated and compared to the freshly prepared samples.

Enhancement in dissolution pattern of piribedil by molecular encapsulation with beta-cyclodextrin.

The aim of this study was to improve the dissolution behavior of piribedil by molecular encapsulation with beta-cyclodextrin (beta-CD). Toward this aim, physical mixing, co-grinding, and spray-drying methods were used to prepare solid binary systems. Differential scanning calorimetry, X-ray diffractometry, and particle size analysis were used to characterize the binary systems obtained. Complexes of piribedil and beta-CD could be prepared using the spray-drying method. Dissolution of piribedil was improved to a great extent by the complex prepared.

Sunblocking efficiency of various TiO(2)-loaded solid lipid nanoparticle formulations(1).

In this study, titanium dioxide (TiO(2)) was incorporated into solid lipid nanoparticle (SLN) formulations using both classical and novel preparation methods. The SLNs were investigated by evaluating their stabilities and physicochemical characteristics. UV-protection abilities of formulations were investigated using in vitro Transpore and Sun To See(TM) test methods. Results have been discussed by comparing the classical SLN formulation with the novel SLN, hybrid SLN (H-SLN) and the emulsion formulations. The results showed the superiority of the H-SLN formulations compared with the classical SLN; all SLN formulations were better when compared with the emulsion formulations considering the UV protection. Incorporation of TiO(2) as a sunscreen agent into SLN formulations gives opportunity to produce stable and safe formulations with reduced amount but high UV-protection ability.

Formulation and in vitro-in vivo evaluation of piribedil solid lipid micro- and nanoparticles.

Modification of the dissolution rate and, thus, the enhancement of the bioavailability of a dopaminergic drug, piribedil, which has a low aqueous solubility and short elimination half-life have been the aim in this study. Preparations of micron and submicron particles using solid lipid carriers have been performed for this purpose. For the avoidance of solvent residues resulting from the preparation technique, cold and hot homogenization methods have been used to prepare solid lipid particles. After obtaining an appropriate particle size, piribedil loading and preparation yield by the use of those two methods, various formulations have been prepared with different lipid, drug and surfactant materials. The factors mentioned were found to affect properties of the particles, and the release rate was found to be the fastest in acidic medium. Suspensions of pure piribedil and a formulation, selected according to the results obtained from in vitro dissolution and particle size experiments, were compared using tremor tests in mice. The same suspensions were applied perorally to rabbits and bioavailability of the solid lipid particle was found to be higher than the pure piribedil. After an in vitro-in vivo evaluation of piribedil solid lipid particles developed for Parkinson's disease therapy, it has been determined that release rate could be controlled and piribedil bioavailability could be improved.

The effect of the type and the concentration of the lipophilic surfactant on the stability and release kinetics of the W/O/W multiple emulsions.

Stable multiple emulsions that contain different lipophilic surfactants in the internal aqueous phase have been formulated. The multiple systems were assessed by evaluating several parameters such as macroscopic aspect, droplet size, percent release and accelerated stability under centrifugation or elevated temperature. The effect of polymeric and monomeric surfactants on the release mechanism and stability was examined. An excess of monomeric surfactant in the oil phase enhances the release rate and decreases stability. The release rate can be decreased by an increase of the lipophilic surfactant concentration. It appears that the more the oil globule swells, the less hydrosoluble drug is released. As a result a high swelling capacity is associated with better stability.

Preparation and in vitro dissolution of salbutamol sulphate microcapsules and tabletted microcapsules.

Salbutamol sulphate is a sympathomimetic amine having a rather short plasma half-life. Aiming to achieve sustained release of this drug through microencapsulation, the coacervation method with a 1:1 core-shell ratio was used. In vitro release rate experiments were performed on the microcapsules prepared using ethyl cellulose as the coating agent and compared to the results of intact drug, the tabletted microcapsules and a commercial tablet. The release rate of salbutamol sulphate could be controlled through microencapsulation. The time for the 50% release of the drug was 15 and 90 min for the tabletted microcapsules and microcapsules respectively. The specific surface area of the intact drug was 0.35 m2/cc while it reduced to 0.06 m2/cc after encapsulation.

Rapid analysis of verapamil in plasma by reversed phase HPLC.

A modified and simple HPLC procedure has been developed for verapamil in plasma. Plasma samples have been vortex-mixed and centrifuged without any need of extraction. The analysis has been performed on a C20 reversed-phase column with fluorometric detection using 5,6-benzoquinoline as an internal standard. Standard curve has been found to be linear for concentrations from 30 to 1000 ng/ml (plasma) for verapamil and no potential source of interference was present. The method has the advantages of speed, small sample requirement and reproducibility. Applicability of the method has been demonstrated by a pharmacokinetic study in 7 rabbits which received a single dose of 0.25 mg verapamil hydrochloride by intravenous administration.