High-dose monotherapy and combination therapy with calcium channel blockers for angina. A comprehensive review of the literature

Peptide Sodium Channels Modulator Mu-Agatoxin-Aa1a Prevents Ischemia-Reperfusion Injury of Cells

Ischemia-reperfusion injury (IRI) is an irreversible functional and structural injury. Restoration of normal oxygen concentration exacerbates the emergence and development of deadly cells. One of the possible moments of reperfusion damage to cells is an increase in the intracellular concentration of sodium ions. In this article, we study the mu-agatoxin-Aa1a, a modulator of sodium channels, on the processes of IRI cells damage. The toxin was synthesized using an automatic peptide synthesizer. Hypoxia was induced by reducing the content of serum and oxygen in the CHO-K1 culture. The influence of the toxin on the level of apoptosis; intracellular concentration of sodium, calcium, and potassium ions; intracellular pH; totality of reactive oxygen species (ROS), nitric oxide (NO), and ATP; and changes in the mitochondrial potential were studied. The experiments performed show that mu-agatoxin-Aa1a effectively prevents IRI of cells. Toxin reduces the level of apoptosis and prevents a decrease in the intracellular concentration of sodium and calcium ions during IRI. Mu-agatoxin-Aa1a contributes to the maintenance of elevated intracellular pH, reduces the intracellular concentration of ROS, and prevents the decrease in intracellular NO concentration and mitochondrial potential under conditions of reoxygenation/reperfusion. An analysis of experimental data shows that the mu-agatoxin-Aa1a peptide has adaptogenic properties. In the future, this peptide can be used to prevent ischemia/reperfusion tissue damage different genesis.

Engineering of Nanospheres Dispersed Microneedle System for Antihypertensive Action

BACKGROUND

A combinational therapy is mostly preferred in hypertension treatment because of low-dose and less side effects like pretibial edema, and gastrointestinal bleeding.

OBJECTIVE

So the objective of the present work was to formulate an advanced drug delivery system in the form of bio-responsive microneedles by incorporating nifedipine, a cardiodepressant and diltiazem, a vasodilator for effective synergism in the treatment of hypertension.

METHODS

The pH-responsive PLGA nanospheres of diltiazem were formulated using Water-in-Oil-in- Water (W/O/W) double emulsion and solvent-diffusion-evaporation technique. These nanospheres were added to nifedipine-PVP mixture and then incorporated into mold to develop microneedles.

RESULTS

The microneedles showed the release of nifedipine almost 96.93± 2.31% for 24 h due to high PVP solubilization. The nanospheres of diltiazem on contact with acidic pH of skin managed to form of CO2 bubbles and increase the internal pressure to burst PLGA shell due to pore formation. The mean blood pressure observed for the normal group was 89.58 ± 3.603 mmHg, whereas the treatment with the new formulation significantly reduced the mean blood pressure up to 84.11 ± 2.98 mmHg in comparison to the disease control group (109.9 ± 1.825 mm Hg).

CONCLUSION

This system co-delivers the drugs nifedipine and diltiazem in hypertension and shows an advance alternative approach over conventional drug delivery system.

Healing Properties of Some Indian Medicinal Plants against Indomethacin-Induced Gastric Ulceration of Rats

The healing activity of the ethanol extracts of Piper betel, Emblica officinalis, Terminalia bellerica, and Terminalia chebula against the indomethacin-induced stomach ulceration has been studied and compared with that of misoprostol. Compared to autohealing, all the drugs accelerated the healing process, albeit to different extents. The relative healing activities of the extracts was P. betel>E. officinalis>T. bellerica~T. chebula, that correlated well with their in vivo antioxidant and mucin augmenting activities. The excellent healing activity of the extracts of P. betel and E. officinalis indicated a major role of mucin protection and regeneration in the healing of nonsteroidal anti-inflammatory drugs mediated stomach ulceration.

Combined Effects of Benidipine and Diltiazem in a Rat Model of Experimental Angina

We examined the combined effects of the calcium channel blockers 1,4-dihydropyridine (benidipine) and benzothiazepine (diltiazem) on vasopressin-induced myocardial ischemia in anesthetized rats, an experimental model of angina. Benidipine (3, 10 microg/kg, i.v.) and diltiazem (300, 1000 microg/kg, i.v.) caused dose-related inhibition of vasopressin-induced S-wave depression, an index of myocardial ischemia. Co-administration of low doses of benidipine (3 microg/kg) and diltiazem (300 microg/kg) almost completely inhibited the S-wave depression, where the efficacy was similar to that obtained with the use of high doses of benidipine (10 microg/kg) or diltiazem (1000 microg/kg). These results suggest that the administration strategy employed may be useful in the treatment of angina pectoris.

Amlodipine in patients with angina uncontrolled by atenolol. A double blind placebo controlled cross over trial

Dihydropyridine calcium antagonists are established second line treatment for angina uncontrolled by beta-adrenergic blockers. Amlodipine is a recently introduced, dihydropyridine with a long half life. In a double blind, placebo controlled, cross over trial we assessed the efficacy and safety of amlodipine in 20 patients with persistent angina despite treatment with atenolol. 17 male patients (mean age 58 y) completed the study. Two patients were withdrawn during placebo because of worsening angina and one withdrew whilst on amlodipine because of palpitations. Compared with baseline, amlodipine prolonged exercise time to S-T segment depression by a median of 12.5%; significantly more than was found with placebo (median 0%). The improvement in exercise time and time to angina also tended to be greater for amlodipine than placebo. GTN consumption, at a median of 1.3/week, was significantly less with amlodipine than placebo (2.8). Attacks of angina were also reduced. Standing systolic and diastolic blood pressures and sitting systolic blood pressure were lower with amlodipine than placebo. Heart rate did not change. There was no change in cardiac output (measured by doppler aortovelography) when amlodipine was added to atenolol. Holter monitor measurements of 24 h maximum and minimum heart rate, heart rate variation and extrasystole counts were the same for amlodipine and placebo. In conclusion, amlodipine is effective in patients with angina inadequately controlled by atenolol alone, and does not interfere with cardiac rhythm or function.

Combination Therapy with Nicardipine and Beta-Adrenergic Blockade for Angina Pectoris

Nicardipine a second-generation dihidropyridine calcium antagonist, has been approved in oral formulation for use in the United States, and is under review for parenteral use. Nicardipine is the most vascular-selective agent of this class currently approved and should, on theoretical grounds, be ideal for combination therapy with beta-adrenergic blocking agents. Studies have shown that the combination of nicardipine and beta-blocking agents offers additional efficacy over monotherapy with either agent alone. The hemodynamic profile of combination therapy appears to be especially favorable in patients with diminished left ventricular function needing therapy with agents of both classes. Adverse effects are few and may be improved compared with other agents of the dihidropyridine class.

Calcium Channel Blockers

Calcium is an integral component in numerous physiological processes and functions. As such, drugs that interfere with the movement of calcium into or out of cells, or the activity of intracellular calcium are useful in treating a variety of disease states. This article will review the calcium channel blockers currently available, along with their approved indications, as well as select dihydropyridine investigational agents and nonapproved indications for their use.