Effect of chloroquine pre-treatment on the metoclopramide's pharmacokinetics after their co-administration.

BACKGROUND: This study evaluated the pharmacokinetic interactions of orally administered chloroquine and metoclopramide. METHODS: The study employed a randomized and two-phase cross-over design with 4-week washout plan. Twelve healthy male volunteers were shortlisted according to the set criteria and were administered with metoclopramide 10 mg PO and chloroquine (a total of 1500 mg) at different intervals which were (500 mg at 0, 6, and 24 h). The concentration of chloroquine and metoclopramide in the blood samples was estimated using a validated HPLC-UV technique to affirm the maximum concentration (Cmax), time to reach Cmax (Tmax), and area under the curve (AUC). RESULTS: Cmax, T1/2, and AUC of metoclopramide were increased up to 20, 10, and 47.8%, respectively, by the concomitantly administering Chloroquine. Chloroquine-treated phase showed increased values of Cmax (ng/ml), AUC (ng.h/ml), and T½ (h), i.e. 41.35 ± 1.61, 504.12 ± 66.25, and 5.72 ± 2.63, as compared to that reference phase i.e. 34.52 ± 4.92, 341.14 ± 112.8, and 5.19 ± 1.14, respectively. CONCLUSIONS: Chloroquine was found to attenuate CYP2D6 activity in healthy Pakistani male volunteers. Hence, patients that are prescribed with metoclopramide or other CYP2D6-substrate drugs require a dose adjustment when administered with chloroquine.

Perampanel increases seizure threshold in pentylenetetrazole-kindled mice and improves behavioral dysfunctions by modifying mRNA expression levels of BDNF/TrkB and inflammatory markers.

Perampanel (PER), a novel 3rd-generation antiseizure drug that modulates altered post-synaptic glutamatergic storming by selectively inhibiting AMPA receptors, is recently approved to treat intractable forms of seizures. However, to date, presumably consequences of long-term PER therapy on the comorbid deleterious psychiatric disturbances and its correlation with neuroinflammatory parameters are not fully investigated in chronic models of epilepsy. Therefore, we investigated the real-time effect of PER on brain electroencephalographic (EEG) activity, behavioral alterations, redox balance, and relative mRNA expression in pentylenetetrazole (PTZ) induced kindling. Male BALB/c mice were pretreated with PER (0.125, 0.25, and 0.5 mg/kg) for 3 weeks and challenged with 11 injections of PTZ at the sub-threshold dose of 40 mg/kg every other day. vEEG from implanted cortical electrodes was monitored to elucidate seizure propagation and behavioral manifestations. Recorded EEG signals exhibited that PER 0.5 mg/kg pretreatment exceptionally impeded the onset of sharp epileptic spike-wave discharges and associated motor symptoms. Additionally, qEEG analysis showed that PER prevented alterations in absolute mean spectral power and reduced RMS amplitude of epileptogenic spikes vs PTZ control. Furthermore, our outcomes illustrated that PER dose-dependently attenuated PTZ-evoked anxiety-like behavior, memory deficits, and depressive-like behavior that was validated by a series of behavioral experiments. Moreover PER, significantly reduced lipid peroxidation, AChE, and increased levels of SOD and total thiol in the mice brain via AMPAR antagonism. Post-PTZ kindling provoked overstimulation of BDNF/TrkB signaling and increased release of pro-inflammatory cytokines that were reversed by PER with suppression of iNOS in brain immune cells. In conclusion, our findings highlight that PER might play an auspicious preventive role in the proepileptic transformation of brain circuits via suppression of BDNF/TrkB signaling and reduced transcriptional levels of neuroinflammatory markers leading to improvised epilepsy-induced neurobehavioral and neurochemical effects.

Effect of clarithromycin pre-treatment on the pharmacokinetics of metoclopramide after their simultaneous oral intake.

OBJECTIVE: The objective of this study was to assess the influence of enzyme suppression on the values of various pharmacokinetic factors of orally administered metoclopramide. METHOD: This study was conducted in two phases and a 4-week duration was adopted for drug washout. This randomized study involved 12 healthy human volunteers who received a single oral dose of metoclopramide 20 mg. After the washout period, volunteers received clarithromycin 500 mg two times per day for consecutive 5 days. On test day (fifth day), a single oral dose of metoclopramide 20 mg was also given to the volunteers, and collection of blood samples was conducted at pre-decided time points. Various pharmacokinetic parameters such as Cmax, Tmax, and AUC0-∞ of metoclopramide were determined by analyzing the blood samples using a validated HPLC-UV method. RESULTS: Clarithromycin increased the mean values of Cmax, AUC0-∞, and T1/2 of metoclopramide by 46%, 78.6%, and 9.8%, respectively. CONCLUSION: Clarithromycin noticeably increased the concentration of plasma metoclopramide. This study's results provide in vivo confirmation of the CYP3A4 involvement in metoclopramide metabolism, in addition to CYP2D6. Therefore, metoclopramide pharmacokinetics may be clinically affected by clarithromycin and other potent enzyme inhibitors.

Influence of Rifampicin Pre-treatment on the In vivo Pharmacokinetics of Metoclopramide in Pakistani Healthy Volunteers Following Concurrent Oral Administration.

BACKGROUND: Metoclopramide is metabolized by various cytochrome P450 (CYP) enzymes such as CYP3A4, CYP1A2, CYP2D6, CYP2C9, and CYP2C19. Rifampicin is a non-selective inducer of P-glycoprotein (P-gp) and CYP enzymes such as CYP3A4 and others. OBJECTIVE: This study was aimed at the evaluation of rifampicin's enzyme induction effect on the pharmacokinetic parameters of orally administered metoclopramide. METHOD: This randomized, single-blind, two-phase cross-over pharmacokinetic study separated by a 4-week washout period was conducted at a single center in Pakistan. It involved twelve Pakistani healthy male volunteers (nonsmokers) divided into two groups. In the reference phase, each volunteer received a single oral dose of 20 mg metoclopramide (Maxolon 10 mg, GlaxoSmithKline, Pakistan), while in the rifampicin-treated phase, each volunteer received 600 mg rifampicin once daily for 6 days through oral route. On day 6, metoclopramide (20 mg) was administered 2 hours after the last pretreatment dose of rifampicin. The serial blood samples were collected on predetermined time points (0, 0.5, 1, 1.5, 2, 3, 4, 6, 8, 10, 12, 14, and 18 h) and analyzed using a validated HPLC method for the determination of pharmacokinetic parameters, i.e. Cmax, Tmax, and AUC0-∞ of metoclopramide. The whole study was monitored by an unblinded clinician for the purpose of volunteer's health safety. RESULTS: All the volunteers participated in the study until the end. Twelve healthy Pakistani males having mean age 26.0 (range 20.6-34.1) years and body mass index 25.1 (range 16.2-31.5) kg/m2 were included in this study after taking written informed consent. Rifampicin significantly (P<0.05) decreased the mean Cmax, AUC0-∞ and T1/2 of metoclopramide by 35%, 68%, and 44%, respectively. The laboratory tests did not reveal any significant change in the biochemical, physical, hematological, or urinalytical values before and after metoclopramide treatment. None of the volunteers complained of any discomfort during the study. CONCLUSION: Rifampicin noticeably decreased the concentration of plasma metoclopramide. These results give in vivo confirmation of the CYP3A4 involvement in the metoclopramide metabolism, in addition to CYP2D6. Therefore, metoclopramide pharmacokinetics may be clinically affected by rifampicin and other potent enzyme inducers.

Evaluation of Pharmacokinetic Interaction of Cilostazol with Metoclopramide after Oral Administration in Human.

BACKGROUND: Metoclopramide is mainly metabolized by CYP2D6, CYP3A4, CYP2C19, and CYP1A2 enzymes, while cilostazol is also metabolized by CYP3A4, CYP2C19, and CYP1A2 enzymes. AIM: This study evaluates the effect of cilostazol on the pharmacokinetics of oral metoclopramide. METHODS: This was a randomized, two-phase cross-over pharmacokinetic study separated by a 4-week wash-out time period, 12 healthy non-smoking volunteers received metoclopramide 20 mg as a single oral dose and after 4 weeks, cilostazol 100 mg twice daily for 4 days then with metoclopramide 20 mg on test day. Serial blood samples were analyzed by using a validated high-performance liquid chromatography-ultraviolet method to determine maximum plasma drug concentration (Cmax), time to reach (Tmax), and area under the curve (AUC0-∞) of metoclopramide. RESULTS: Cilostazol increased the mean Cmax, AUC0-∞ and half-life (T1/2) of metoclopramide by 6%, 27% and by 0.79 %, respectively. In addition, Tmax of metoclopramide was delayed by cilostazol. CONCLUSION: The results showed delayed Tmax of metoclopramide by cilostazol, which could lead to the conclusion that cilostazol affects the absorption of metoclopramide. Both drugs when necessary to administer together must not be administered at the same time especially when given in gastroparesis patients.

PREVALENCE OF HEPATITIS C IN DIABETIC PATIENTS: A PROSPECTIVE STUDY.

There is a strong evidence of the relationship between diabetes and hepatitis C however, there are certain gaps in the literature. Therefore, this study was carried out to determine the prevalence of hepatitis C in diabetic patients and risk factors associated with it, to evaluate the presence of possible relationship between hepatitis C and diabetes. Serological testing for anti HCV antibody was carried out on a sample of 100 diabetic patients visiting the diabetic clinic Nishtar Medical College and Hospital Multan. An anti HCV antibody test was carried out on HCV ELISA 3.0 (third generation) kit, locally purchased. Data about demographic information and history of risk factors for HCV was collected from diabetic patients using a structured questionnaire as an experimental tool, after taking informed consent. Data of about 100 non diabetic subjects (volunteer blood donors) was taken from the blood bank of that hospital. Prevalence rate of HCV infection among diabetic patients was recorded 19% and in the control group (non-diabetics) was 3%. Prevalence of HCV infection is higher in type 2 diabetic patients as compared to type 1 diabetic patients (84% vs. 16%). Diabetic patients between age group 46-55 years of age has high prevalence rates (47%) as compared to healthy individuals. Female diabetic patients have higher seropositivity (74%) as compared to male diabetic patients (26%). High prevalence of HCV infection has been reported among diabetic patients with duration of disease = 11 years (47%). Most of the patients were married (95%) and from urban locality (89%) and almost all were poor (99%). HCV positive diabetic patients have also history of blood transfusion (16%), hospital admissions (84%), major surgical procedure (63%), family history of hepatitis C (16%), razor sharing among males (16%) and comb sharing (79%). There was not any I/V drug addict (or history of I/V drug addiction), and tattooing, nose/ear piercing from contaminated needle and toothbrush sharing have not been seen among the participants of research.The results showed that in the present study the prevalence of HCV infection is six times higher in diabetic patients as compared to non-diabetic subjects (control group).