Triapin
Triapin Uses, Dosage, Side Effects, Food Interaction and all others data.
Felodipine is a long-acting 1,4-dihydropyridine calcium channel blocker (CCB)b. It acts primarily on vascular smooth muscle cells by stabilizing voltage-gated L-type calcium channels in their inactive conformation. By inhibiting the influx of calcium in smooth muscle cells, felodipine prevents calcium-dependent myocyte contraction and vasoconstriction. Felodipine is the most potent CCB in use and is unique in that it exhibits fluorescent activity. In addition to binding to L-type calcium channels, felodipine binds to a number of calcium-binding proteins, exhibits competitive antagonism of the mineralcorticoid receptor, inhibits the activity of calmodulin-dependent cyclic nucleotide phosphodiesterase, and blocks calcium influx through voltage-gated T-type calcium channels. Felodipine is used to treat mild to moderate essential hypertension.
Felodipine belongs to the dihydropyridine (DHP) class of calcium channel blockers (CCBs), the most widely used class of CCBs. There are at least five different types of calcium channels in Homo sapiens: L-, N-, P/Q-, R- and T-type. It was widely accepted that CCBs target L-type calcium channels, the major channel in muscle cells that mediates contraction; however, some studies have shown that felodipine also binds to and inhibits T-type calcium channels. T-type calcium channels are most commonly found on neurons, cells with pacemaker activity and on osteocytes. The pharmacologic significance of T-type calcium channel blockade is unknown. Felodipine also binds to calmodulin and inhibits calmodulin-dependent calcium release from the sarcoplasmic reticulum. The effect of this interaction appears to be minor. Another study demonstrated that felodipine attenuates the activity of calmodulin-dependent cyclic nucleotide phosphodiesterase (CaMPDE) by binding to the PDE-1B1 and PDE-1A2 enzyme subunits. CaMPDE is one of the key enzymes involved in cyclic nucleotides and calcium second messenger systems. Felodipine also acts as an antagonist to the mineralcorticoid receptor by competing with aldosterone for binding and blocking aldosterone-induced coactivator recruitment of the mineralcorticoid receptor. Felodipine is able to bind to skeletal and cardiac muscle isoforms of troponin C, one of the key regulatory proteins in muscle contraction. Though felodipine exhibits binding to many endogenous molecules, its vasodilatory effects are still thought to be brought about primarily through inhibition of voltage-gated L-type calcium channels. Similar to other DHP CCBs, felodipine binds directly to inactive calcium channels stabilizing their inactive conformation. Since arterial smooth muscle depolarizations are longer in duration than cardiac muscle depolarizations, inactive channels are more prevalent in smooth muscle cells. Alternative splicing of the alpha-1 subunit of the channel gives felodipine additional arterial selectivity. At therapeutic sub-toxic concentrations, felodipine has little effect on cardiac myocytes and conduction cells.
Ramipril is an angiotensin converting enzyme (ACE) inhibitor, which after hydrolysis to ramiprilat, blocks the conversion of angiotensin I to the vasoconstrictor substance, angiotensin II. So, inhibition of ACE by ramipril results in decreased plasma angiotensin II, which leads to decreased vasopressor activity and decreased aldosterone secretion. Thus ramipril exerts its antihypertensive activity. It is also effective in the management of heart failure and reduction of the risk of stroke, myocardial infarction and death from cardiovascular events. It is long acting and well tolerated; so, can be used in long term therapy.
Ramipril is an ACE inhibitor similar to benazepril, fosinopril and quinapril. It is an inactive prodrug that is converted to ramiprilat in the liver, the main site of activation, and kidneys. Ramiprilat confers blood pressure lowing effects by antagonizing the effect of the RAAS. The RAAS is a homeostatic mechanism for regulating hemodynamics, water and electrolyte balance. During sympathetic stimulation or when renal blood pressure or blood flow is reduced, renin is released from the granular cells of the juxtaglomerular apparatus in the kidneys. In the blood stream, renin cleaves circulating angiotensinogen to ATI, which is subsequently cleaved to ATII by ACE. ATII increases blood pressure using a number of mechanisms. First, it stimulates the secretion of aldosterone from the adrenal cortex. Aldosterone travels to the distal convoluted tubule (DCT) and collecting tubule of nephrons where it increases sodium and water reabsorption by increasing the number of sodium channels and sodium-potassium ATPases on cell membranes. Second, ATII stimulates the secretion of vasopressin (also known as antidiuretic hormone or ADH) from the posterior pituitary gland. ADH stimulates further water reabsorption from the kidneys via insertion of aquaporin-2 channels on the apical surface of cells of the DCT and collecting tubules. Third, ATII increases blood pressure through direct arterial vasoconstriction. Stimulation of the Type 1 ATII receptor on vascular smooth muscle cells leads to a cascade of events resulting in myocyte contraction and vasoconstriction. In addition to these major effects, ATII induces the thirst response via stimulation of hypothalamic neurons. ACE inhibitors inhibit the rapid conversion of ATI to ATII and antagonize RAAS-induced increases in blood pressure. ACE (also known as kininase II) is also involved in the enzymatic deactivation of bradykinin, a vasodilator. Inhibiting the deactivation of bradykinin increases bradykinin levels and may sustain the effects of ramiprilat by causing increased vasodilation and decreased blood pressure.
| Trade Name | Triapin |
| Generic | felodipine + ramipril |
| Type | Tablet |
| Therapeutic Class | |
| Manufacturer | SANOFI |
| Available Country | United Kingdom, Portugal |
| Last Updated: | September 19, 2023 at 7:00 am |
Uses
Felodipine is a calcium channel blocker used to treat hypertension.
For the treatment of mild to moderate essential hypertension.
Ramiprilis used for the following cases:
- Mild to severe hypertension
- Congestive Heart failure.
- To reduce the risk of stroke, myocardial infarction and death from cardiovascular events in patients with a history of cardiovascular disease.
- Proteinuric non-diabetic nephropathy.
Triapin is also used to associated treatment for these conditions: High Blood Pressure (Hypertension)Cardiovascular Events, Diabetic Nephropathy, Heart Failure, Heart Failure With Reduced Ejection Fraction (HFrEF), High Blood Pressure (Hypertension), Myocardial Infarction, Nondiabetic proteinuric chronic kidney disease, Stroke, High risk cardiovascular event
How Triapin works
Felodipine decreases arterial smooth muscle contractility and subsequent vasoconstriction by inhibiting the influx of calcium ions through voltage-gated L-type calcium channels. It reversibly competes against nitrendipine and other DHP CCBs for DHP binding sites in vascular smooth muscle and cultured rabbit atrial cells. Calcium ions entering the cell through these channels bind to calmodulin. Calcium-bound calmodulin then binds to and activates myosin light chain kinase (MLCK). Activated MLCK catalyzes the phosphorylation of the regulatory light chain subunit of myosin, a key step in muscle contraction. Signal amplification is achieved by calcium-induced calcium release from the sarcoplasmic reticulum through ryanodine receptors. Inhibition of the initial influx of calcium decreases the contractile activity of arterial smooth muscle cells and results in vasodilation. The vasodilatory effects of felodipine result in an overall decrease in blood pressure. Felodipine may be used to treat mild to moderate essential hypertension.
Ramipril inhibits the RAAS system by binding to and inhibiting ACE thereby preventing the conversion of angiotensin I to angiotensin II. As plasma levels of angiotensin II fall, less activation of the G-protein coupled receptors angiotensin receptor I (AT1R) and angiotensin receptor II (AT2R) occurs.
AT1R mediates vasoconstriction, inflammation, fibrosis, and oxidative stress through a variety of signaling pathways. These include Gq coupling to the inositol triphosphate pathway, activation of phospholipases C, A2, and D which contribute to eicosanoid production, activation of Ca2+ These counteracting effects are shared by the Mas receptor which is activated by Ang(1-7), a subtype of angiotensin produced by plasma esterases from AngI or by ACE2 from AngII produced through a secondary pathway by tonin and cathepsin G. Ang(1-7) also activates AT2R although the bulk of its effect is mediated by MasR.
ACE is also responsible for the breakdown of bradykinin. The resulting buildup of bradykinin due to ACE inhibition is thought to mediate the characteristic dry-cough as a side effect of ACE inhibitor medications.
Dosage
Triapin dosage
Dosage of Ramipril must be adjusted according to the patient tolerance and response.
Hypertension: For the management of hypertension in adults not receiving a diuretic, the usual initial dose of Ramipril is 1.25 - 2.5 mg once daily. Dosage generally is adjusted no more rapidly than at 2 week intervals. The usual maintenance dosage in adults is 2.5 - 20 mg daily given as a single dose or in 2 divided doses daily. If BP is not controlled with Ramipril alone, a diuretic may be added.
Congestive heart failure after myocardial infarction: In this case, Ramipril therapy may be initiated as early as 2 days after myocardial infarction. An initial dose of 2.5 mg twice daily is recommended, but if hypotension occurs, dose should be reduced to 1.25 mg twice daily. Therapy is then titrated to a target daily dose of 5 mg twice daily.
Prevention of major cardiovascular events: In this case, the recommended dose is 2.5 mg once daily for the first week of therapy and 5 mg once daily for the following 3 weeks; dosage then may be increased, as tolerated, to a maintenance dosage of 10 mg once daily.
Side Effects
Ramipril is generally well tolerated. Dizziness, headache, fatigue and asthenia are commonly reported side effects. Other side effects occurring less frequently include symptomatic hypotension, cough, nausea, vomiting, diarrhoea, rash, urticaria, oliguria, anxiety, amnesia etc. Angioneurotic oedema, anaphylactic reactions and hyperkalaemia have also been reported rarely.
Toxicity
Symptoms of overdose include excessive peripheral vasodilation with marked hypotension and possibly bradycardia. Oral rat LD50 is 1050 mg/kg.
Symptoms of overdose may include excessive peripheral vasodilation (with marked hypotension and shock), bradycardia, electrolyte disturbances, and renal failure. Cases of ACE inhibitor induced hepatotoxicity have been reported in humans and presented as acute jaundice and elevated liver enzymes. Removal of the ACE inhbitor resulted in a decline in liver enzymes and re-challenge produced a subsequent increase.
There were no observed tumerogenic effects at chronic doses up to 500mg/kg/day to rats for 24 months or at doses up to 1000mg/kg/day to mice for 18 months. For both species doses were administered by gavage and equivalent to 200 time the maximum recommended human exposure based on body surface area.
No mutagenic activity was detected in the Ames test in bacteria, the micronucleus test in mice, unscheduled DNA synthesis in a human cell line, or a forward gene-mutation assay in a Chinese hamster ovary cell line. Several metabolites of ramipril also produced negative results in the Ames test.
No effects on fertility were seen in rats at doses up to 500mg/kg/day. No teratogenicity was observed in rats and cynomolgus monkeys at doses 400 times the maximum recommended human exposure nor in rabbites at 2 times the maximum recommended human exposure.
LD50 10 g/kg (rat). LD50 10.5 g/kg (mouse). LD50 1 g/kg (dog).
Precaution
Ramipril should be used with caution in patients with impaired renal function, hyperkalaemia, hypotension, and impaired hepatic function.
Interaction
With Diuretics: Patients on diuretics, especially those in whom diuretic therapy was recently instituted, may occasionally experience an excessive reduction of blood pressure after initiation of therapy with ramipril.
With Potassium Supplements and Potassium-sparing Diuretics: Ramipril can attenuate potassium loss caused by thiazide diuretics. Potassium-sparing diuretics (spironolactone, amiloride, triamterene, and others) or potassium supplements can increase the risk of hyperkalemia.
Other: Neither ramipril nor its metabolites have been found to interact with food, digoxin, antacid, furosemide, cimetidine, indomethacin, and simvastatin. The combination of ramipril and propranolol showed no adverse effects on dynamic parameters (blood pressure and heart rate). The co-administration of ramipril and warfarin did not adversely affect the anticoagulant effects of the latter drug.
Volume of Distribution
- 10 L/kg
Elimination Route
Is completely absorbed from the gastrointestinal tract; however, extensive first-pass metabolism through the portal circulation results in a low systemic availability of 15%. Bioavailability is unaffected by food.
The extent of absorption is at least 50-60%.. Food decreases the rate of absorption from the GI tract without affecting the extent of absorption. The absolute bioavailabilities of ramipril and ramiprilat were 28% and 44%, respectively, when oral administration was compared to intravenous administration. The serum concentration of ramiprilat was unchanged when capsules were opened and the contents dissolved in water, dissolved in apple juice, or suspended in apple sauce.
Half Life
17.5-31.5 hours in hypertensive patients; 19.1-35.9 hours in elderly hypertensive patients; 8.5-19.7 in healthy volunteers.
Plasma concentrations of ramiprilat decline in a triphasic manner. Initial rapid decline represents distribution into tissues and has a half life of 2-4 hours. The half life of the apparent elimination phase is 9-18 hours, which is thought to represent clearance of free drug. The half-life of the terminal elimination phase is > 50 hours and thought to represent clearance of drug bound to ACE due to its slow dissociation. The half life of ramiprilat after multiple daily doses (MDDs) is dose-dependent, ranging from 13-17 hours with 5-10 mg MDDs to 27-36 hours for 2.5 mg MDDs.
Clearance
- 0.8 L/min [Young healthy subjects]
The renal clearance of ramipril and ramiprilat was reported to be 7.2 and 77.4 mL/min/1.73m2. The mean renal clearance of ramipril and ramiprilat is reported to be 10.7 and 126.8 mL/min in healthy elderly patients with normal renal function, additionally the Cmax of ramiprilat is approximately 20% higher in this population. While the pharmacokinetics of ramipril appear unaffected by reduced renal function, the plasma concentration and half-life of ramiprilat are increased. In patient's with hepatic failure the concentration of ramipril is initially increased while the tmax of ramiprilat is prolonged due to a reduced ability to metabolize the drug. However, steady state concentrations of ramiprilat are the same in hepatic failure as in healthy patients.
Elimination Route
Although higher concentrations of the metabolites are present in the plasma due to decreased urinary excretion, these are inactive. Animal studies have demonstrated that felodipine crosses the blood-brain barrier and the placenta.
Following oral administration, about 60% of the dose is eliminated in the urine as unchanged ramipril (6
Pregnancy & Breastfeeding use
If pregnancy is detected, ramipril should be discontinued as early as possible unless continued use is considered life saving. Ramipril should not be used during lactation.
Contraindication
It is contraindicated in patients who are hypersensitive to any component of this product and in patients with a history of angioedema related to previous treatment with a ACE inhibitor.
Special Warning
Dosage in renal impairment: For the patients with hypertension and renal impairment, the recommended initial dose is 1.25 mg Ramipril once daily. Subsequent dosage should be titrated according to individual tolerance and BP response, up to a maximum of 5 mg daily. For the patients with heart failure and renal impairment, the recommended dose is 1.25 mg once daily. The dose may be increased to 1.25 mg twice daily and up to a maximum dose of 2.5 mg twice daily depending upon clinical response and tolerability.
Use in children: No information is yet available on the use of Ramipril in children.
Acute Overdose
Limited data on human overdosage are available. The most likely clinical manifestations would be symptoms attributable to hypotension. Because the hypotensive effect of Ramipril is achieved through vasodilation and effective hypovolemia, it is reasonable to treat Ramipril overdosage by infusion of normal saline solution.
Storage Condition
Store at cool & dry place, protect from light and moisture.
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