Effects of pharmacogenetics on pharmacokinetics and toxicity of doxorubicin in Egyptian breast cancer patients

This study investigates the impact of single nucleotide polymorphisms in genes (SLC22A16 and CBR1) involved in the pharmacokinetics and toxicity of doxorubicin (DOX) in Egyptian female patients with breast cancer.Patients administered DOX (60 mg/m2) for 4 cycles every 3 weeks. The peak DOX plasma concentration was measured using a validated chromatographic method. The genotyping for the selected SNPs, SLC22A16 T > C (rs714368), and CBR1 C > T (rs20572), was performed by RT-PCR. Patients were monitored for hematological and cardiac toxicities.The variant carriers of CBR1 C > T (rs20572) exhibited significantly higher DOX concentration, but no significant association to DOX-induced hematological toxicity. On the other hand, SLC22A16 T > C (rs714368) had no significant influence on DOX plasma concentration, but was significantly correlated with lower risk of neutropenia (OR 0.31, 95% CI 0.12-0.75, p = 0.01) and leukopoenia (OR 0.18, 95% CI 0.07-0.5, p = 0.001). DOX-related cardiotoxicity was correlated with the cumulative dose of DOX (R = 0.238, p = 0.017), but not with any of the two examined SNPs.Genetic polymorphisms in SLC22A16 and CBR1 may explain the inter-individual variations in DOX pharmacokinetics and toxicity. Using pharmacogenetic testing is important to customise drug therapy for cancer patients treated with anthracyclines.

Statins Increase the Bioavailability of Fixed-Dose Combination of Sofosbuvir/Ledipasvir by Inhibition of P-glycoprotein

BACKGROUND

Coadministration of statins and direct acting antiviral agents is frequently used. This study explored the effects of both atorvastatin and lovastatin on pharmacokinetics of a fixed-dose combination of sofosbuvir/ledipasvir "FDCSL".

METHODS

12 healthy volunteers participated in a randomized, three-phase crossover trial and were administered a single atorvastatin dose 80 mg plus tablet containing 400/90 mg FDCSL, a single lovastatin dose 40 mg plus tablet containing 400/90 mg FDCSL, or tablets containing 400/90 mg FDCSL alone. Liquid chromatography-tandem mass spectrometry was used to analyze plasma samples of sofosbuvir, ledipasvir and sofosbuvir metabolite "GS-331007" and their pharmacokinetic parameters were determined.

RESULTS

Atorvastatin caused a significant rise in sofosbuvir bioavailability as explained by increasing in AUC0-∞ and Cmax by 34.36% and 11.97%, respectively. In addition, AUC0-∞ and Cmax of GS-331007 were increased by 73.73% and 67.86%, respectively after atorvastatin intake. Similarly, co-administration of lovastatin with FDCSL increased the bioavailability of sofosbuvir, its metabolite (AUC0-∞ increase by 17.2%, 17.38%, respectively, and Cmax increase by 12.03%, 22.24%, respectively). However, neither atorvastatin nor lovastatin showed a change in ledipasvir bioavailability. Hepatic elimination was not affected after statin intake with FDCSL. Compared to lovastatin, atorvastatin showed significant increase in AUC0-∞ and Cmax of both sofosbuvir and its metabolite.

CONCLUSIONS

Both atorvastatin and lovastatin increased AUC of sofosbuvir and its metabolite after concurrent administration with FDCSL. Statins' P-glycoprotein inhibition is the attributed mechanism of interaction. The increase in sofosbuvir bioavailability was more pronounced after atorvastatin intake. Close monitoring is needed after co-administration of atorvastatin and FDCSL.

A randomized controlled trial comparing the effects of Vitamin E, Ursodeoxycholic acid and Pentoxifylline on Egyptian non-alcoholic steatohepatitis patients

OBJECTIVE

Currently, no NASH-specific therapies are approved by the US Food and Drug Administration. This study aimed to compare the clinical effect of vitamin E (Vit. E), Ursodeoxycholic Acid (UDCA) and pentoxifylline (PTX) on Egyptian patients with NASH with exploration of their possible roles on inflammatory cytokines and chemokines mainly Interleukin 6 (IL6) and Monocyte Chemoattractant Protein-1 (CCL2/MCP-1).

PATIENTS AND METHODS

We conducted a 3-month, randomized, single-blind study in 102 Egyptian NASH patients who were divided into three groups; group 1 received Vit. E 400 mg twice a day, group 2 received UDCA 250 mg twice a day and group 3 received PTX 400 mg twice daily. Liver aminotransferases (AST, ALT), IL6, CCL2/MCP-1, albumin, bilirubin, and lipid panel were measured both before and after intervention intake.

RESULTS

A significant decrease was found in liver aminotransferases, serum cytokine and chemokine in participants after Vit. E, UDCA or PTX intake. Compared to the UDCA and PTX groups, liver aminotransferases, serum cytokine and chemokine showed a more statistically significant reduction after Vit. E administration (50%, 43%, 57% and 55% for ALT, AST, IL6 and CCL2/MCP-1, respectively). In contrast, other biochemical tests showed non-significant change after any drug intake. None of the tested drugs showed significant safety issues in this population.

CONCLUSIONS

Treatment with Vit. E, UDCA and PTX was both safe and effective in improving hepatic aminotransferases and inflammatory markers in Egyptian NASH patients. The superior effect of Vit. E compared to UDCA and PTX may suggest that oxidative stress plays a key role in disease progression of NASH patients. Moreover, IL6 and CCL2/MCP-1 may be used with or without ALT for treatment evaluation of NASH people.

Pharmacokinetic interaction between atorvastatin and fixed-dose combination of sofosbuvir/ledipasvir in healthy male Egyptian volunteers

PURPOSE

Comorbid conditions of heart and liver disorders added to HCV-induced hepatic steatosis make co-administration of statins, and direct-acting antivirals is common in clinical practice. This study aimed to evaluate the pharmacokinetic interaction of atorvastatin and fixed-dose combination of sofosbuvir/ledipasvir "FDCSL" with rationalization to the underlying mechanism.

METHODS

A randomized, three-phase crossover study that involves 12 healthy volunteers was performed. Participants received a single-dose of atorvastatin 80 mg alone, atorvastatin 80-mg plus tablets containing 400/90 mg FDCSL, or tablets containing 400/90 mg FDCSL alone. Plasma samples were analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) for atorvastatin, sofosbuvir, ledipasvir, and sofosbuvir metabolite "GS-331007," and their pharmacokinetics parameters were determined.

RESULTS

Compared to atorvastatin alone, the administration of FDCSL caused a significant increase in both areas under the concentration-time curve from time zero to infinity (AUC_0-∞) and maximum plasma concentration (C_max) of atorvastatin by 65.5% and 156.0%, respectively. Also, atorvastatin caused a significant increase in the AUC_0-∞ and C_max of sofosbuvir by 32.0% and 11.0%, respectively. Similarly, AUC_0-∞ and C_max of sofosbuvir metabolite significantly increased by 84.0% and 74.0%, respectively. However, ledipasvir AUC_0-∞ showed no significant change after atorvastatin intake. The elimination rate in all drugs revealed no significant changes.

CONCLUSION

After concurrent administration of FDCSL with atorvastatin, the AUC_0-∞ of both atorvastatin and sofosbuvir were increased. Caution should be taken with close monitoring for possible side effects after co-administration of atorvastatin and FDCSL in clinical practice.

The effect of genetic variations on ribavirin pharmacokinetics and treatment response in HCV-4 Egyptian patients receiving sofosbuvir/daclatasvir and ribavirin

PURPOSE

This study aimed to investigate the effect of single nucleotide polymorphisms (SNPs) of genes involved in ribavirin (RBV) transport (SLC28A2 gene, ABCB1 gene and ABCB11 gene) on the clinical outcome and pharmacokinetics of ribavirin in HCV- 4 Egyptian patients.

METHOD

100 patients treated with sofosbuvir/daclatasvir and ribavirin for 12 weeks. The SNP genotyping was performed by real-time PCR using high resolution melting analysis. Ribavirin plasma trough concentrations were determined at week 4 of therapy using a liquid chromatography/tandem mass spectrometry (LC-MS/MS). For clinical outcomes, sustained virological response (SVR), liver function tests (ALT and AST), total bilirubin, albumin, serum creatinine, hemoglobin, leukocyte count, and platelet count were measured.

RESULTS

Concerning RBV pharmacokinetics, ABCB1 2677 G > T SNP and ABCB11 1331 T > C SNP were statistically associated with RBV C_trough levels after 4 weeks of therapy. ABCB11 1331 T > C SNP revealed significant association with clinical outcomes (SVR). SLC28A2-146 A > T SNP has not showed any statistically significant association with RBV plasma levels or response.

CONCLUSION

SNP genotyping for ABCB1 and ABCB11 genes can help in better personalized medicine for maximizing response for ribavirin as explored by the significant association between polymorphism in ABCB1 and ABCB11 genes and ribavirin pharmacokinetics and the significant association of ABCB11 1331 T > C SNP with clinical response.