Quantification of letermovir in human serum using high-performance liquid chromatography with diode array detection.

A simple, rapid, cost-effective and sensitive high-performance liquid chromatography method with diode array detection was developed and validated for the quantification of letermovir, a compound approved for prophylaxis of cytomegalovirus infection and disease in adult recipients of an allogeneic hematopoietic stem cell transplant. Sorafenib was used as internal standard. Samples were pre-treated by liquid-liquid extraction with tert-butyl methylether.

Association of mitotane with chylomicrons and serum lipoproteins: practical implications for treatment of adrenocortical carcinoma.

Objective: Oral mitotane (o,p'-DDD) is a cornerstone of medical treatment for adrenocortical carcinoma (ACC).

Aim: Serum mitotane concentrations >14  mg/l are targeted for improved efficacy but not achieved in about half of patients. Here we aimed at a better understanding of intestinal absorption and lipoprotein association of mitotane and metabolites o,p'-dichlorodiphenylacetic acid (o,p'-DDA) and o,p'-dichlorodiphenyldichloroethane (o,p'-DDE).

Impact of benzodiazepines on posaconazole serum concentrations. A population-based pharmacokinetic study on drug interaction.

Objectives: Posaconazole is broadly used for antifungal prophylaxis and therapy. Current data suggest a concentration-dependent effect. Unlike other triazoles, cytochrome P450 is not a relevant route of biotransformation for posaconazole but glucuronidation, which might lead to a different spectrum of drug interactions.

Relevance of timing for determination of posaconazole plasma concentrations.

For posaconazole, drug monitoring is suggested, but the relevance of timing for the determination of posaconazole concentration (PC) remains unclear. We investigated the variation of PC before and 4 and 8 h after the administration of 400 mg of posaconazole. Mean concentrations were 645, 678, and 616 ng/ml.

High-performance liquid chromatographic method for the determination of sorafenib in human serum and peritoneal fluid.

Purpose: Sorafenib is recommended for therapy of advanced hepatocellular carcinoma and renal cell carcinoma. Preclinical data indicate a relation between dose and antitumor efficacy. In clinical trials, adverse events improve after dose reduction suggesting a dose-dependent toxicity.

Simultaneous determination of voriconazole and posaconazole concentrations in human plasma by high-performance liquid chromatography.

A simple, sensitive, and selective high-performance liquid chromatographic method for the simultaneous determination of voriconazole and posaconazole concentrations in human plasma was developed and validated. Quantitative recovery following liquid-liquid extraction with diethyl ether was achieved. Linearity ranged from 0.

Drug monitoring of pyrimethamine during maintenance therapy of toxoplasmic encephalitis in patients with advanced HIV infection during HAART.

Background: Prophylaxis of toxoplasmic encephalitis was performed with pyrimethamine in 6 patients with advanced HIV infection during combination therapy with protease inhibitors.

Material/methods: Steady-state plasma pyrimethamine (PYR) levels were measured by gas chromatography. Protease inhibitor plasma concentrations were analyzed trough concentration by high pressure liquid chromatography.

Highly sensitive gas chromatographic determination of ethanol in human urine samples.

In order to evaluate recent alcohol consumption, a very sensitive and specific gas chromatographic method for ethanol determination in human urine samples was developed. The non-invasive method was performed without any pretreatment and carried out on a Stabilwax capillary column, 30 m x 0.53 mm x 1.

Rapid determination of nevirapine in human plasma by gas chromatography.

A sensitive and rapid gas chromatographic method has been developed to determine the levels of the HIV-1 non-nucleoside reverse transcriptase inhibitor nevirapine in human plasma. Quantitative recovery following liquid-liquid-extraction with diethylether from 500 microl of human plasma was achieved. Subsequently, the assay was performed with a CP-Sil 5CB capillary column, 15 m x 0.