Laboratory tests used to guide antimicrobial therapy

Dermatologic Disease-Directed Targeted Therapy (D3T2): The Application of Biomarker-Based Precision Medicine for the Personalized Treatment of Skin Conditions-Precision Dermatology

Precision dermatology uses individualized dermatologic disease-directed targeted therapy (D3T2) for the management of dermatoses and for the evaluation and therapy of cutaneous malignancies. Personalized/precision strategies are based on biomarkers that are most frequently derived from tissue transcriptomic expression or genomic sequencing or from circulating cytokines. For instance, the pathologic diagnosis of a pigmented lesion and determining the prognosis of a malignant melanocytic neoplasm can be enhanced by genomic/transcriptomic analysis. In addition to biopsy, innovative techniques have been developed for obtaining transcriptomes in skin conditions; as an example, patches can be applied to a psoriasis plaque for a few minutes to capture the epidermis/upper dermis transcriptome. Atopic dermatitis and prurigo nodularis may also be candidate conditions for precision dermatology. Precision dermatology has a role in managing melanoma and nonmelanoma skin cancers and rare cutaneous tumors-such as perivascular epithelioid cell tumor (PEComa)-that can originate in or metastasize to the skin. For instance, advanced/metastatic basal cell carcinomas can be treated with Hedgehog inhibitors (vismodegib and sonidegib) targeting the smoothened (SMO) or patched 1 (PTCH1) gene alterations that are a hallmark of these cancers and activate the Hedgehog pathway. Advanced/metastatic basal and cutaneous squamous cell cancers often have a high tumor mutational burden (which predicts immunotherapy response); immune checkpoint blockade with cemiplimab, a programmed cell death protein 1 (PD1) inhibitor, is now approved for these malignancies. Gene expression profiling of primary cutaneous squamous cell carcinoma can identify those individuals at high risk for subsequent metastases. In the realm of rare neoplasms, PEComas-which can originate in the skin, albeit uncommonly-have tuberous sclerosis complex 1 (TSC1)/tuberous sclerosis complex 2 (TSC2) gene alterations, which activate mammalian target of rapamycin (mTOR) signaling, and can be suppressed by nab-sirolimus, now approved for this condition. In summary, precision dermatologic techniques/strategies are an important emerging approach for evaluation and management of skin disorders and cutaneous neoplasms, and may serve as a paradigm for the application of precision medicine beyond dermatology.

The use of referenced-EEG (rEEG) in assisting medication selection for the treatment of depression

OBJECTIVE

To evaluate the efficacy of rEEG(®)-guided pharmacotherapy for the treatment of depression in those circumstances where rEEG and STAR*D provided different recommendations.

MATERIALS AND METHODS

This was a randomized, single-blind, parallel group, 12 center, US study of rEEG-guided pharmacotherapy vs. the most effective treatment regimens reported in the NIH sponsored STAR*D study. Relatively treatment-resistant subjects ≥18 years who failed one or more antidepressants were required to have a QIDS-16-SR score ≥13 and a MADRS score ≥26 at baseline. All subjects underwent a washout of all current medications (with some protocol-specified exceptions) for at least five half-lives before receiving a QEEG and rEEG report. Subjects randomized to rEEG were assigned a regimen based on the rEEG report. Control subjects who had failed only SSRI's in their current episode were randomized to receive venlafaxine XR. Control subjects who had failed antidepressants from ≥2 classes of antidepressants were randomized to receive a regimen from Steps 2-4 of the STAR*D study. Treatment lasted 12 weeks. The primary outcome measures were change from baseline for self-rated QIDS-SR16 and Q-LES-Q-SF.

RESULTS

A total of 114 subjects were randomized and 89 subjects were evaluable. rEEG-guided pharmacotherapy exhibited significantly greater improvement for both primary endpoints, QIDS-SR16 (-6.8 vs. -4.5, p<0.0002) and Q-LES-Q-SF (18.0 vs. 8.9, p<0.0002) compared to control, respectively, as well as statistical superiority in 9 out of 12 secondary endpoints.

CONCLUSIONS

These results warrant additional studies to determine the role of rEEG-guided psychopharmacology in the treatment of depression. If these results were confirmed, rEEG-guided pharmacotherapy would represent an easy, relatively inexpensive, predictive, objective office procedure that builds upon clinical judgment to guide antidepressant medication choice.

Pharmacokinetic/Pharmacodynamic Considerations in Community-Acquired Lower Respiratory Tract Infections

To accomplish the goal of both clinical and microbiological cure in the treatment of lower respiratory tract infections, microbiological data along with pharmacokinetic and pharmacodynamic data should be used. Recent studies have determined 2important antibacterial pharmacokinetic/ pharmacodynamic parameters that differ among classes of antimicrobial agents. The 2major groups include the antibiotics that exhibit concentration-dependent killing with a postantibiotic effect and time-dependent killing with minimal to moderate postantibiotic effects. For drugs that are concentration dependent (aminoglycosides, fluoroquinolones), the area under the concentration-time curve (AUC/MIC) is the most important predictor of bacteriological eradication. Alternatively, for antibiotics that exhibit time-dependent killing (-lactams, macrolides), time above the MIC ( T >MIC) is probably the major parameter that determines efficacy. Using these parameters provides the tools needed for appropriate antibiotic dosing.

Susceptibility testing. Phenotypic and genotypic tests for bacteria and mycobacteria

Genotypic-based methods hold promise for the rapid and accurate detection or confirmation of antimicrobial resistance; however, phenotypic methods will continue to have an advantage when resistance to the same antimicrobial agent may be caused by several different mechanisms. The diversity of genetic mechanisms may exceed the capabilities of current molecular technology. Genotypic assays have the ability to detect resistance but not susceptibility. Although resutls can be obtained rapidly, many molecular methods are labor-intensive, expensive, and lack standardization. Clinical studies will be required to validate the genotypic approach to detection of antimicrobial resistance. Molecular assays are also at risk for false-positive results because of contamination of specimens by other specimens that carry the DNA targeted for the assay, or carryover of amplified target DNA (amplicons) from a previous PCR assay during sample preparation. Detection of certain genetic resistance loci in clinical specimens must be interpreted with caution, because organisms in normal flora may also harbor the same loci. All these factors must be taken into consideration when introducing a genotypic method in the clinical laboratory. Other considerations include cost, turnaround time, and assay performance. It must be emphasized that the bedside assessment of the patient should always be considered in addition to the results of antimicrobial susceptibility tests (whether phenotypic or genotypic) so that the best outcome is assured for the patient.

Principles of selection and use of antibacterial agents. In vitro activity and pharmacology

The selection of an antimicrobial treatment regimen is based on many factors, including the nature of the infection, the identity and susceptibility pattern of the infecting organisms, and the pharmacokinetics and pharmacodynamics of the antibacterial drugs. This article discusses principles of susceptibility testing, pharmacology, and monitoring of therapy.

Antibiotic troubleshooting in primary care

Allergic reactions, adverse effects, and drug interactions are an inevitable part of antimicrobial prescribing. A working knowledge of these issues remains paramount, especially when administering such agents to patients who are pregnant, infected with HIV, or who have renal insufficiency. The discussion also includes antibiotic-OTC drug interactions and antibiotic hypersensitivity.

Therapeutic Drug Monitoring of Therapy for Infectious Diseases

Optimal use of antimicrobial agents is dependent on a multitude of factors. Empiric therapy should be based on the patient's underlying disease states, the most likely organisms suspected, and susceptibility patterns. Once susceptibilities are known, therapy should be streamlined. A number of factors must be evaluated during therapy. The site of infections must be considered when choosing antimicrobial agents. The minimum inhibitory concentration (MIC) should be evaluated; the antimicrobial agent's MIC should be at or below the breakpoint for the organism to be considered susceptible. Antimicrobial agent selec tion and dosing should take into consideration not only the MIC, but also the post-antibiotic effect, if appli cable. Serum concentrations of antimicrobial agents should be obtained and evaluated to ensure thera peutic levels and to avoid potential toxicities. The choice of an antimicrobial agent is complicated by the emergence of antibiotic resistance. Drug-resistant gram-positive and gram-negative infections are in creasing. We must attempt to control resistance by choosing appropriate antimicrobial agents and maxi mizing dosages. Pharmacists can play a critical role in the management of patients who receive antimi crobial agents.

Therapeutic Drug Monitoring of Therapy for Infectious Diseases

Optimal use of antimicrobial agents is dependent on a multitude of factors. Empiric therapy should be based on the patient's underlying disease states, the most likely organisms suspected, and susceptibility patterns. Once susceptibilities are known, therapy should be streamlined. A number of factors must be evaluated during therapy. The site of infections must be considered when choosing antimicrobial agents. The minimum inhibitory concentration (MIC) should be evaluated ; the antimicrobial agent's MIC should be at or below the breakpoint for the organism to be considered susceptible. Antimicrobial agent selection and dosing should take into consideration not only the MIC, but also the post-antibiotic effect, if applicable. Serum concentrations of antimicrobial agents should be obtained and evaluated to ensure therapeutic levels and to avoid potential toxicities. The choice of an antimicrobial agent is complicated by the emergence of antibiotic resistance. Drug-resistant gram-positive and gram-negative infections are increasing. We must attempt to control resistance by choosing appropriate antimicrobial agents and maximizing dosages. Pharmacists can play a critical role in the management of patients who receive antimicrobial agents.