Comparative Pharmacological Properties among Calcium Channel Blockers: T-Channel versus L-Channel Blockade

Cardiology ◽  
1998 ◽  
Vol 89 (1) ◽  
pp. 10-15 ◽  
Author(s):  
Georg Noll ◽  
Thomas F. Lüscher
Keyword(s):  
Calcium Channel ◽  
Calcium Channel Blockers ◽  
Channel Blockers ◽  
Pharmacological Properties ◽  
Channel Blockade

scholarly journals The Need for a Rational Approach to Vasoconstrictive Syndromes: Transcranial Doppler and Calcium Channel Blockade in Reversible Cerebral Vasoconstriction Syndrome

2016 ◽  
Vol 8 (2) ◽  
pp. 161-171 ◽  
Author(s):  
Elisabeth B. Marsh ◽  
Wendy C. Ziai ◽  
Rafael H. Llinas
Keyword(s):  
Calcium Channel ◽  
Calcium Channel Blockers ◽  
Transcranial Doppler ◽  
Reversible Cerebral Vasoconstriction Syndrome ◽  
Rational Approach ◽  
Channel Blockers ◽  
Channel Blockade ◽  
Calcium Channel Blockade ◽  
Acute Setting ◽  
Cerebral Vasoconstriction

Introduction: Reversible cerebral vasoconstriction syndrome (RCVS) typically affects young patients and left untreated can result in hemorrhage or ischemic stroke. Though the disorder has been well characterized in the literature, the most appropriate way to diagnose, treat, and evaluate therapeutic response remains unclear. In previous studies, transcranial Doppler ultrasound (TCD) has shown elevated velocities indicative of vasospasm. This imaging modality is noninvasive and inexpensive; an attractive option for diagnosis and therapeutic monitoring if it is sensitive enough to detect changes in the acute setting given that RCVS often affects the distal vessels early in the course of disease. There is also limited data that calcium channel blockade may be effective in treating vasospasm secondary to RCVS, though the agent of choice, formulation, and dose are unclear. Methods: We report a small cohort of seven patients presenting with thunderclap headache whose vascular imaging was consistent with RCVS. All were treated with calcium channel blockade and monitored with TCD performed every 1–2 days. Results: On presentation, TCD correlated with standard neuroimaging findings of vasospasm (on MR, CT, and conventional angiography). TCD was also able to detect improvement in velocities in the acute setting that correlated well with initiation of calcium channel blockade. Long-acting verapamil appeared to have the greatest effect on velocities compared to nimodipine and shorter-acting calcium channel blockers. Conclusion: Though small, our cohort demonstrates potential utility of TCD to monitor RCVS, and relative superiority of extended-release verapamil over other calcium channel blockers, illustrating the need for larger randomized trials.

Mechanism of verapamil calcium channel blockade-induced hyperprolactinemia

1996 ◽  
Vol 270 (1) ◽  
pp. E96-E100 ◽  
Author(s):  
S. R. Kelley ◽  
T. J. Kamal ◽  
M. E. Molitch
Keyword(s):  
Calcium Channel ◽  
Calcium Channel Blockers ◽  
Channel Blocker ◽  
Serum Prolactin ◽  
Decarboxylase Activity ◽  
Channel Blockers ◽  
Low Doses ◽  
Channel Blockade ◽  
Calcium Channel Blockade ◽  
Before And After

Verapamil, a phenylalkylamine calcium channel blocker, causes a doubling of serum prolactin (PRL) levels in humans. To determine whether the mechanism involved a decrease in the PRL response to dopamine (DA), we infused low doses of DA, finding that the percent inhibition of PRL was not affected by verapamil (max %decrements for 0.003, 0.01, and 0.03 microgram.kg-1.min-1 doses of DA, respectively, 86.7 +/- 19.1, 73.2 +/- 24.8, and 65.2 +/- 20.0% without verapamil and 93.4 +/- 24.6, 79.7 +/- 14.9, and 58.0 +/- 18.1% with verapamil). To determine whether the PRL elevation was due to a decrease in hypothalamic generation of DA, we measured the inhibition of PRL by L-dopa before and after inhibition of peripheral decarboxylase activity with carbidopa. Without verapamil, L-dopa alone and carbidopa-L-dopa caused similar maximum decreases in PRL levels of 83.2 +/- 2.5 and 80.3 +/- 2.0%, respectively. With verapamil, the PRL maximum decrement with L-dopa was 85.2 +/- 2.7% and with carbidopa-L-dopa was 76.3 +/- 1.9% (P < 0.01). We also found that dihydropyridine and benzothiazepine calcium channel blockers had no effect on PRL. These results suggest that verapamil acts by decreasing central DA generation, possibly through N-type calcium channels.

Electroanalytical Methods for Determination of Calcium Channel Blockers

2019 ◽  
Vol 15 (3) ◽  
pp. 207-218 ◽  
Author(s):  
Fatma Ağın
Keyword(s):  
Calcium Channel ◽  
Calcium Channel Blockers ◽  
Channel Blocker ◽  
Heart Diseases ◽  
Dosage Forms ◽  
Channel Blockers ◽  
Electroanalytical Methods ◽  
Pharmaceutical Dosage Forms ◽  
Ischemic Heart Diseases

Background:Calcium Channel Blockers (CCBs) are widely used in the treatment of cardiovascular and ischemic heart diseases in recent years. They treat arrhythmias by reducing cardiac cycle contraction and also benefit ischemic heart diseases. Electroanalytical methods are very powerful analytical methods used in the pharmaceutical industry because of the determination of therapeutic agents and/or their metabolites in clinical samples at extremely low concentrations (10-50 ng/ml). The purpose of this review is to gather electroanalytical methods used for the determination of calcium channel blocker drugs in pharmaceutical dosage forms and biological media selected mainly from current articles.Methods:This review mainly includes recent determination studies of calcium channel blockers by electroanalytical methods from pharmaceutical dosage forms and biological samples. The studies of calcium channel blockers electroanalytical determination in the literature were reviewed and interpreted.Results:There are a lot of studies on amlodipine and nifedipine, but the number of studies on benidipine, cilnidipine, felodipine, isradipine, lercanidipine, lacidipine, levamlodipine, manidipine, nicardipine, nilvadipine, nimodipine, nisoldipine, nitrendipine, diltiazem, and verapamil are limited in the literature. In these studies, DPV and SWV are the most used methods. The other methods were used less for the determination of calcium channel blocker drugs.Conclusion:Electroanalytical methods especially voltammetric methods supply reproducible and reliable results for the analysis of the analyte. These methods are simple, more sensitive, rapid and inexpensive compared to the usually used spectroscopic and chromatographic methods.

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