Older blood pressure medications-do they still have a place?

Ultrafast Reaction of the Drug Hydralazine with Apurinic/Apyrimidinic Sites in DNA Gives Rise to a Stable Triazolo[3,4-a]phthalazine Adduct

The clinically used antihypertensive agent hydralazine rapidly generates hydrazone-derived adducts by reaction with apurinic/apyrimidinic (also known as abasic or AP) sites in many different sequences of duplex DNA. The reaction rates are comparable to those of some AP-trapping reagents previously described as "ultrafast." Initially, reversible formation of a hydrazone adduct is followed by an oxidative cyclization reaction that generates a chemically stable triazolo[3,4-a]phthalazine adduct. The net result is that the reaction of hydralazine with AP sites in duplex DNA yields a rapid and irreversible adduct formation. Although the hydrazone and triazolo[3,4-a]phthalazine adducts differ by only two mass units, it was possible to use MALDI-TOF-MS and ESI-QTOF-nanospray-MS to quantitatively characterize mixtures of these adducts by deconvolution of overlapping isotope envelopes. Reactions of hydralazine with the endogenous ketone pyruvate do not prevent the formation of the hydralazine-AP adducts, providing further evidence that these adducts have the potential to form in cellular DNA. AP sites are ubiquitous in cellular DNA, and rapid, irreversible adduct formation by hydralazine could be relevant to the pathogenesis of systemic drug-induced lupus erythematosus experienced by some patients. Finally, hydralazine might be developed as a probe for the detection of AP sites, the study of cellular BER, and marking the location of AP sites in DNA-sequencing analyses.

Comparison of primary care prescriptions for old and very old hypertensive patients

BACKGROUND

Elderly and very elderly individuals might be subject to different approaches for the treatment of hypertension. We aimed to compare drug utilization in hypertensive old patients and very old patients in primary care, along with the evaluation of potentially inappropriate drug prescribing.

METHODS

In this cross-sectional study, we compared prescriptions of 65-79-year-old (old patient prescriptions [OPP], n = 433,988) vs. ≥80-year-old (very old patient prescriptions [VOPP], n = 134,079) with "essential hypertension" diagnosis, issued by 3:1 systematically-sampled primary care physicians (n = 1431) in İstanbul throughout 2016. Drug utilization patterns and distribution of antihypertensives based on drug class and combination status were evaluated. Frequency of potentially inappropriate drugs per Beers Criteria were identified and compared.

RESULTS

Antihypertensive monotherapy practice was less common in OPP than VOPP (43.3% vs. 45.3%; p < 0.001). In both groups,the most commonly prescribed drugs were beta-blockers for monotherapy (37.4% vs. 33.1%, p < 0.001) and thiazide diuretics for combined therapy (69.8% vs. 67.4%, p < 0.001). Metoprolol was the most commonly prescribed antihypertensive both in OPP and VOPP (15.3% vs. 14.8%). Furosemide was ranked 10th in OPP and 3rd in VOPP (2.7% vs. 5.5%). Cardiovascular system drugs were the most commonly encountered potentially inappropriate medications in both groups (263.9 vs. 283.4 per 10,000 prescriptions, p = 0.004). Regarding antihypertensive drugs, 2.2% of those in OPP and 2.4% of those in VOPP were identified as potentially inappropriate (p = 0.002).

DISCUSSION

Prescribing preferences to old and very old patients mostly showed slight differences. Almost half of prescriptions comprising antihypertensive monotherapy might imply hesitancy to prescribe combinations. Overuse of risky drugs such as furosemide in both groups, especially in the very elderly, requires more attention.

Risks associated with continuation of potentially inappropriate antihypertensive medications in older adults receiving hemodialysis

BACKGROUND AND OBJECTIVES

After dialysis initiation, older adults may experience orthostatic or post-dialysis hypotension. Some orthostasis-causing antihypertensives (i.e., central alpha agonists and alpha blockers), are considered potentially inappropriate medications (PIMs) for older adults because they carry more risk than benefit. We sought to (1) describe antihypertensive PIM prescribing patterns before and after dialysis initiation and (2) ascertain the potential risk of adverse outcomes when these medications are continued after dialysis initiation.

DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS

Using United States Renal Data System data, we evaluated monthly prevalence of antihypertensive PIM claims in the period before and after dialysis initiation among older adults aged ≥66 years initiating in-center hemodialysis in the US between 2013 and 2014. Patients with an antihypertensive PIM prescription at hemodialysis initiation and who survived for 120 days were classified as 'continuers' or 'discontinuers' based on presence or absence of a refill within the 120 days after initiation. We compared rates of hospitalization and risk of death across these groups from day 121 through 24 months after dialysis initiation.

RESULTS

Our study included 30,760 total patients, of whom 5981 (19%) patients had an antihypertensive PIM claim at dialysis initiation and survived ≥120 days. Most [65% (n = 3920)] were continuers. Those who continued (versus discontinued) were more likely to be black race (26% versus 21%), have dual Medicare-Medicaid coverage (31% versus 27%), have more medications on average (12 versus 9) and have no functional limitations (84% versus 80%). Continuers experienced fewer all-cause hospitalizations and deaths, but neither were statistically significant after adjustment (Hospitalization: RR 0.93, 95% CI 0.86, 1.00; Death: HR 0.89, 95% CI: 0.78-1.02).

CONCLUSIONS

Nearly one in five older adults had an antihypertensive PIM at dialysis initiation. Among those who survived ≥120 days, continuation of an antihypertensive PIM was not associated with increased risk of all-cause hospitalization or mortality.

Bioactivity-Guided Isolation and Identification of New and Immunosuppressive Monoterpenoid Indole Alkaloids from Rauvolfia yunnanensis Tsiang

Three new 11-hydroxyburnamine (1) and rauvoyunnanines A-B (2-3), and fourteen known (4-17) monoterpenoid indole alkaloids were isolated from the total alkaloids extract of Rauvolfia yunnanensis, which exhibited promising immunosuppressive activity on T cell proliferation in preliminary screening. Their structures were determined by analysis of high-resolution electrospray ionization mass (HRESIMS), ultraviolet (UV) and nuclear magnetic resonance (NMR) data, and by comparison with the literature. All the alkaloids were evaluated for inhibitory activity on T cell proliferation. Among them, one new compound (1) and reserpine (6) exhibited moderate immunosuppressive activity, with IC50 values of 5.9 μM and 5.0 μM, respectively.

No association between low-dose reserpine use and depression in older hypertensive patient: result of a multicenter, cross-sectional study

Background

Reserpine is currently used by millions of Chinese hypertensive patients, in spite of the continued concern of its depressogenic effect, even when used in low dose. This study aimed to investigate the association between low-dose reserpine use and depression in older Chinese hypertensive patient.

Methods

In this cross-sectional, case-control study, we recruited patient aged 60 years or over who had regularly taken one or two tables of “compound reserpine and triamterene tablets (CRTTs)” for more than one year (reserpine user) from 26 community health centers located in 10 provinces in China. For each patient who took CRTTs, we selected an age (within five years) and sex matched hypertensive patient who had never taken any drugs containing reserpine (non-reserpine user) as control. Depressive symptoms were evaluated using a Chinese depression scale adapted from the Zung Self-Rating Depression Scale. Demographic, clinical data and laboratory examination results within six months were collected.

Results

From August 2018 to December 2018, 787 reserpine user and 787 non-reserpine user were recruited. The mean age of all study subjects was 70.3 years, with about equal numbers of males and females. The mean depression score was 40.4 in reserpine users and 40.6 in non-reserpine users (P = 0.7). The majority of study subject had a depression score < 53 (87.6% in reserpine users and 88.2% in non-reserpine users, respectively). There were no significant differences in the prevalence of mild, moderate or severe depression in reserpine users and non-reserpine users.

Conclusions

There is no association between low-dose reserpine use and depression in older hypertensive patient. The role of reserpine in the treatment and control of hypertension should be reconsidered; and further studies, especially randomized, controlled clinical trials to compare efficacy and safety of reserpine and other widely recommended anti-hypertensive agents are needed.

Preferred Fourth-Line Pharmacotherapy for Resistant Hypertension: Are We There Yet?

Resistant hypertension (RH) is defined as blood pressure (BP) that remains above target levels despite adherence to at least three different antihypertensive medications, typically including a diuretic. Epidemiological studies estimate that RH is increasing in prevalence, and is associated with detrimental health outcomes. The pathophysiology underlying RH is complex, involving multiple, overlapping contributors including activation of the renin-angiotensin aldosterone system and the sympathetic nervous system, volume overload, endothelial dysfunction, behavioural and lifestyle factors. Hypertension guidelines currently recommend specific pharmacotherapy for 1st, 2nd and 3rd-line treatment, however no specific fourth-line pharmacotherapy is provided for those with RH. Rather, five different antihypertensive drug classes are generally suggested as possible alternatives, including: mineralocorticoid receptor antagonists, α1-adrenergic antagonists, α2-adrenergic agonists, β-blockers, and peripheral vasodilators. Each of these drug classes vary in their efficacy, tolerability and safety profile. This review summarises the available data on each of these drug classes as a potential fourth-line drug and reveals a lack of robust clinical evidence for preferred use of most of these classes in the setting of RH. Moreover, there is a lack of direct comparative trials that could assist in identifying a preferred fourth-line pharmacologic approach and in providing evidence for hypertensive guidelines for adequate treatment of RH.

Herbal Medications in Cardiovascular Medicine

Herbal medications are commonly used for clinical purposes, including the treatment of cardiovascular conditions. Compared with conventional medications, herbal medications do not require clinical studies before their marketing or formal approval from regulatory agencies, and for this reason their efficacy and safety are rarely proven. In this review, we summarize available evidence on herbal medications mostly used in cardiovascular medicine. We show that the use of these medications for the treatment of cardiovascular diseases is often not supported by scientific evidence. Despite most of these herbs showing an effect on biological mechanisms related to the cardiovascular system, data on their clinical effects are lacking. Potential relevant side effects, including increased risk of drug interactions, are described, and the possibility of contamination or substitution with other medications represents a concern. Physicians should always assess the use of herbal medications with patients and discuss the possible benefits and side effects with them.

Evaluation of Biosynthetic Pathway and Engineered Biosynthesis of Alkaloids

Varieties of alkaloids are known to be produced by various organisms, including bacteria, fungi and plants, as secondary metabolites that exhibit useful bioactivities. However, understanding of how those metabolites are biosynthesized still remains limited, because most of these compounds are isolated from plants and at a trace level of production. In this review, we focus on recent efforts in identifying the genes responsible for the biosynthesis of those nitrogen-containing natural products and elucidating the mechanisms involved in the biosynthetic processes. The alkaloids discussed in this review are ditryptophenaline (dimeric diketopiperazine alkaloid), saframycin (tetrahydroisoquinoline alkaloid), strictosidine (monoterpene indole alkaloid), ergotamine (ergot alkaloid) and opiates (benzylisoquinoline and morphinan alkaloid). This review also discusses the engineered biosynthesis of these compounds, primarily through heterologous reconstitution of target biosynthetic pathways in suitable hosts, such as Escherichia coli, Saccharomyces cerevisiae and Aspergillus nidulans. Those heterologous biosynthetic systems can be used to confirm the functions of the isolated genes, economically scale up the production of the alkaloids for commercial distributions and engineer the biosynthetic pathways to produce valuable analogs of the alkaloids. In particular, extensive involvement of oxidation reactions catalyzed by oxidoreductases, such as cytochrome P450s, during the secondary metabolite biosynthesis is discussed in details.

Silymarin Constituent 2,3-Dehydrosilybin Triggers Reserpine-Sensitive Positive Inotropic Effect in Perfused Rat Heart

2,3-dehydrosilybin (DHS) is a minor flavonolignan component of Silybum marianum seed extract known for its hepatoprotective activity. Recently we identified DHS as a potentially cardioprotective substance during hypoxia/reoxygenation in isolated neonatal rat cardiomyocytes. This is the first report of positive inotropic effect of DHS on perfused adult rat heart. When applied to perfused adult rat heart, DHS caused a dose-dependent inotropic effect resembling that of catecholamines. The effect was apparent with DHS concentration as low as 10 nM. Suspecting direct interaction with β-adrenergic receptors, we tested whether DHS can trigger β agonist-dependent gene transcription in a model cell line. While DHS alone was unable to trigger β agonist-dependent gene transcription, it enhanced the effect of isoproterenol, a known unspecific β agonist. Further tests confirmed that DHS could not induce cAMP accumulation in isolated neonatal rat cardiomyocytes even though high concentrations (≥ 10 μM) of DHS were capable of decreasing phosphodiesterase activity. Pre-treatment of rats with reserpine, an indole alkaloid which depletes catecholamines from peripheral sympathetic nerve endings, abolished the DHS inotropic effect in perfused hearts. Our data suggest that DHS causes the inotropic effect without acting as a β agonist. Hence we identify DHS as a novel inotropic agent.

Development of an LC-MS/MS method for determining the pharmacokinetics of clonidine following oral administration of Zhenju antihypertensive compound

Zhenju antihypertensive compound (ZJAHC) is a combined Chinese-Western medicine formula including clonidine (CLO), hydrochlorothiazide (HCT), rutin, Chrysanthemum indicum extract and pearl powder. Compared with CLO preparations, ZJAHC shows improved activities and decreased adverse effects. It is believed that the side effects of CLO are caused by its high peak plasma concentration. Hence, study of the influence of ZJAHC on the pharmacokinetic behaviors of clonidine seems essential. In present study, the plasma concentrations of CLO were determined with a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. The MS/MS transitions monitored for clonidine and internal standard were 230.2 → 213.1 and 152.2 → 110.2, respectively. The analyte was quantified in a single run within 3 min. The pharmacokinetic study showed that the area under the plasma concentration-time curve of CLO in ZJAHC (60 µg/kg CLO) was similar to that of CLO-HCT-high (120 µg/kg CLO) but the peak concentration was much lower than that in CLO-HCT-high. ZJAHC could enhance the bioavailability without greatly increasing peak concentration of clonidine. This comprehensive effect of enhancing the bioavailability and avoiding the high peak plasma concentration for CLO might mainly result from the co-contribution of Western medicine and traditional Chinese medicine (TCM), while the effect of TCM was stronger than that of Western medicine.

Covalent adduct formation between the antihypertensive drug hydralazine and abasic sites in double- and single-stranded DNA

Hydralazine (4) is an antihypertensive agent that displays both mutagenic and epigenetic properties. Here, gel electrophoretic, mass spectroscopic, and chemical kinetics methods were used to provide evidence that medicinally relevant concentrations of 4 rapidly form covalent adducts with abasic sites in double- and single-stranded DNA under physiological conditions. These findings raise the intriguing possibility that the genotoxic properties of this clinically used drug arise via reactions with an endogenous DNA lesion rather than with the canonical structure of DNA.

Prescribing of potentially inappropriate medications for the elderly: an analysis based on the PRISCUS list

BACKGROUND

The PRISCUS list of potentially inappropriate medications (PIM) for the elderly was published in 2010 and is the first systematically constructed list of this type in Germany. The aim of the present study is to estimate the baseline prevalence of the prescribing of PIM, as defined by the PRISCUS list.

METHODS

Pseudonymized claims data from three statutory health insurances in Germany, which together covered more than 8 million insurants, for the year 2007 were used to determine the age- and sex-standardized one-year period prevalence of PIM among the elderly, as well as the frequency of PIM prescribing per person. The study population included all insurants who were at least 65 years old and were continuously insured throughout the year 2007 or died during that year.

RESULTS

Of the 804 400 elderly persons in the study population, 201 472 (25.0%) received at least one PIM prescription in 2007. The PIM prevalence was higher in women than in men (32.0% vs. 23.3%) and increased with age. The most commonly prescribed PIM were amitriptyline (2.6%), acetyldigoxin (2.4%), tetrazepam (2.0%), and oxazepam (2.0%). 8.8% of all elderly persons received the same PIM drug four or more times in 2007.

CONCLUSION

These data show that PIM were frequently prescribed to elderly persons in Germany before the PRISCUS list was published. Medications on the PRISCUS list are not necessarily absolutely contraindicated, and this study contained no information about the individual risk/benefit analyses that may have been carried out before these drugs were prescribed; thus, no conclusion can be drawn about the prevalence of inappropriate prescribing. Further research is needed to validate the PRISCUS list, which was generated by expert consensus, as a basis for therapeutic guidelines in geriatric medicine.

What is the role of aldosterone excess in resistant hypertension and how should it be investigated and treated?

Resistant hypertension has evolved as an important global health care problem. Primary aldosteronism is one of several potentially reversible causes of resistant hypertension. Primary aldosteronism can be effectively treated, when recognized, with a mineralocorticoid receptor antagonist, such as spironolactone and eplerenone. Each of these compounds can reduce blood pressure as monotherapy or when given with a range of other antihypertensive drug classes. These compounds have distinctive pharmacokinetic and pharmacodynamic patterns that require some forethought in their use before they are prescribed. However, as the use of mineralocorticoid-blocking agents has gradually increased, the hazards inherent to use of such drugs has become more apparent. Whereas the endocrine side effects of spironolactone are in most cases little more than a cosmetic annoyance, the potassium-sparing effects of both spironolactone and eplerenone can prove fatal if sufficient degrees of hyperkalemia develop. However, for most patients the risk of developing hyperkalemia in and of itself should not discourage the prudent clinician from bringing these compounds into play. Hyperkalemia should always be considered as a likelihood in any patient receiving one or the other of these medications. As such, steps should be taken to lessen the likelihood of it occurring if therapy is being contemplated with agents in this class.