Effect of Zidovudine Therapy in Patients with HIV Infection on Endogenous Interferon Plasma Levels and the Hepatic Cytochrome P450 Enzyme System

Chemotherapy ◽  
1998 ◽  
Vol 44 (3) ◽  
pp. 174-180 ◽  
Author(s):  
N.H. Brockmeyer ◽  
B. Barthel ◽  
L. Mertins ◽  
M. Goos
Keyword(s):  
Cytochrome P450 ◽  
Hiv Infection ◽  
Plasma Levels ◽  
Enzyme System ◽  
Zidovudine Therapy ◽  
Cytochrome P450 Enzyme ◽  
P450 Enzyme ◽  
Cytochrome P450 Enzyme System ◽  
Hepatic Cytochrome

Pharmacogenetics of the hepatic cytochrome P450 enzyme system: its relevance for prescribing in psychiatry

1998 ◽  
Vol 15 (3) ◽  
pp. 96-99
Author(s):  
Alan O'Donohoe ◽  
Michael Gill
Keyword(s):  
Genetic Variation ◽  
Cytochrome P450 ◽  
Current Knowledge ◽  
Enzyme System ◽  
Genetic Influences ◽  
Cytochrome P450 Enzyme ◽  
Cytochrome P450 Enzymes ◽  
P450 Enzyme ◽  
Cytochrome P450 Enzyme System ◽  
Hepatic Cytochrome

AbstractThis article reviews the current knowledge regarding the hepatic cytochrome P450 system, with particular reference to its effect on psychotherapeutic medication. The metabolic processes – by which drugs are broken down in the liver by cytochrome P450 enzymes – are affected by genetic variation between individuals, inhibition and induction of these enzymes by other drugs, disease and age. Genetic influences and enzyme inhibition/induction are discussed in particular detail in this article.

Drug Interactions of Macrolides: Emphasis on Dirithromycin

1997 ◽  
Vol 31 (3) ◽  
pp. 349-356 ◽  
Author(s):  
Vish S Watkins ◽  
Ron E Polk ◽  
Jennifer L Stotka
Keyword(s):  
Cytochrome P450 ◽  
Drug Interactions ◽  
Ethinyl Estradiol ◽  
Enzyme System ◽  
Cytochrome P450 Enzyme ◽  
Cytochrome P450 Enzymes ◽  
Kidney Transplant Recipients ◽  
P450 Enzyme ◽  
Cytochrome P450 Enzyme System ◽  
Clinically Significant

Objective To describe the drug interactions of dirithromycin, a new macrolide, and to compare them with those of other macrolides. Data Sources A literature search was performed using MEDLINE to identify articles published between January 1980 and July 1995 concerning the drug interactions of macrolides. Published abstracts were also examined. All studies using dirithromycin were performed under the sponsorship of Eli Lilly and Company. Data Synthesis Erythromycin, the first macrolide discovered, is metabolized by the cytochrome P450 enzyme system. By decreasing their metabolism, erythromycin can interact with other drugs metabolized by the cytochrome P450 enzymes. The lack of such interactions would be a desirable feature in a newer macrolide. We describe studies performed to detect any interactions of dirithromycin with cyclosporine, theophylline, terfenadine, warfarin, and ethinyl estradiol. The studies showed that dirithromycin, like azithromycin, is much less likely to cause the interactions detected with clarithromycin and erythromycin. A review of the literature showed differences among macrolides in their abilities to inhibit cytochrome P450 enzymes and, thus, to cause drug–drug interactions. Erythromycin and clarithromycin inhibit cytochrome P450 enzymes, and have been implicated in clinically significant interactions. Azithromycin and dirithromycin neither inhibit cytochrome P450 enzymes nor are implicated in clinically significant drug–drug interactions. Conclusions Dirithromycin, a new macrolide, does not inhibit the cytochrome P450 enzyme system. The concomitant use of dirithromycin with cyclosporine, theophylline, terfenadine, warfarin, or ethinyl estradiol was studied in pharmacokinetic and pharmacodynamic studies. In vitro, dirithromycin did not bind cytochrome P450. In healthy subjects, erythromycin increases the clearance of cyclosporine by 51%, whereas dirithromycin causes no significant changes in the pharmacokinetics of cyclosporine. In kidney transplant recipients, administration of dirithromycin was associated with a significant (p < 0.003) decrease of 17.4% in the clearance of cyclosporine. In patients taking low-dose estradiol, the administration of dirithromycin caused a significant (p < 0.03) increase of 9.9% in the clearance of ethinyl estradiol; escape ovulation did not occur. Unlike erythromycin and clarithromycin, dirithromycin had no significant effects on the pharmacokinetics of theophylline, terfenadine, or warfarin. The alterations typical of drug interactions that are based on inhibition of the cytochrome P450 system occurring with erythromycin and clarithromycin were not observed with dirithromycin.

Serotonin syndrome in a Parkinson disease patient after intake of an ethanol-containing homeopathic medication

2020 ◽  
Vol 10 (4) ◽  
pp. 219-222 ◽  
Author(s):  
Cezar Thomas R Suratos ◽  
Mark M Del Rosario ◽  
Roland Dominic G Jamora
Keyword(s):  
Nervous System ◽  
Cytochrome P450 ◽  
Parkinson Disease ◽  
Serotonin Syndrome ◽  
Enzyme System ◽  
Disease Patient ◽  
Cytochrome P450 Enzyme ◽  
Parkinson Disease Patient ◽  
P450 Enzyme ◽  
Cytochrome P450 Enzyme System

Serotonin syndrome is due to excess serotonin in the nervous system. We document a case of an elderly Parkinson disease patient who has been neurologically stable on rasagiline and escitalopram for 1 year but developed serotonin syndrome after intake of an ethanol-containing homeopathic medication. The patient presented with seizures, autonomic dysfunction and neuromuscular hyperexcitability. Maintenance medications were discontinued, hydration, sedation and respiratory support were provided with resolution of the symptoms. The combination of escitalopram and ethanol, both metabolized by the cytochrome P450 enzyme system can lead to serotonin syndrome. Our case highlights the importance of drug interactions in patients taking several medications. Additionally, the intake of medicines, may it be conventional or homeopathic medicine, without the guidance of a trained and competent physician, may lead to serious consequences for the patient.

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