Pritor/Amlodipine

Pritor/Amlodipine Uses, Dosage, Side Effects, Food Interaction and all others data.

Angiotensin II is formed from angiotensin I in a reaction catalyzed by angiotensin-converting enzyme (ACE, kininase II). Angiotensin II is the principal pressor agent of the renin-angiotensin system, with effects that include vasoconstriction, stimulation of synthesis and release of aldosterone, cardiac stimulation, and renal reabsorption of sodium. Telmisartan blocks the vasoconstrictor and aldosterone-secreting effects of angiotensin II by selectively blocking the binding of angiotensin II to the AT1 receptor in many tissues, such as vascular smooth muscle and the adrenal gland. Its action is therefore independent of the pathways for angiotensin II synthesis.

There is also an AT2 receptor found in many tissues, but AT2 is not known to be associated with cardiovascular homeostasis. Telmisartan has a much greater affinity ( > 3,000 fold) for the AT1 receptor than for the AT2 receptor.

Blockade of the renin-angiotensin system with ACE inhibitors, which inhibit the biosynthesis of angiotensin II from angiotensin I, is widely used in the treatment of hypertension. ACE inhibitors also inhibit the degradation of bradykinin, a reaction also catalyzed by ACE. Because telmisartan does not inhibit ACE (kininase II), it does not affect the response to bradykinin. Whether this difference has clinical relevance is not yet known. Telmisartan does not bind to or block other hormone receptors or ion channels known to be important in cardiovascular regulation.

Blockade of the angiotensin II receptor inhibits the negative regulatory feedback of angiotensin II on renin secretion, but the resulting increased plasma renin activity and angiotensin II circulating levels do not overcome the effect of telmisartan on blood pressure.

Telmisartan is an orally active nonpeptide angiotensin II antagonist that acts on the AT1 receptor subtype. It has the highest affinity for the AT1 receptor among commercially available ARBS and has minimal affinity for the AT2 receptor. New studies suggest that telmisartan may also have PPARγ agonistic properties that could potentially confer beneficial metabolic effects, as PPARγ is a nuclear receptor that regulates specific gene transcription, and whose target genes are involved in the regulation of glucose and lipid metabolism, as well as anti-inflammatory responses. This observation is currently being explored in clinical trials. Angiotensin II is formed from angiotensin I in a reaction catalyzed by angiotensin-converting enzyme (ACE, kininase II). Angiotensin II is the principal pressor agent of the renin-angiotensin system, with effects that include vasoconstriction, stimulation of synthesis and release of aldosterone, cardiac stimulation, and renal reabsorption of sodium. Telmisartan works by blocking the vasoconstrictor and aldosterone secretory effects of angiotensin II.

Pritor/Amlodipine
Uses
Dosage
Side Effect
Precautions
Interactions
Uses during Pregnancy
Uses during Breastfeeding
Accute Overdose
Food Interaction
Half Life
Volume of Distribution
Clearance
Interaction With other Medicine
Contradiction
Storage

Trade Name	Pritor/Amlodipine
Generic	telmisartan + amlodipine besilate
Type
Therapeutic Class
Manufacturer
Available Country	Australia
Last Updated:	September 19, 2023 at 7:00 am

Uses

Essential hypertension: Amlodipine is efficacious as monotherapy in the treatment of hypertension. It may be used in combination with other antihypertensive agents.Angina pectoris: Amlodipine is indicated for the treatment of chronic stable angina pectoris ... Read more

Telmisartan is an angiotensin II receptor blocker (ARB) used for treatment of hypertension and Cardiovascular (CV) risk reduction in patients who are used for ACE inhibitors.

Pritor/Amlodipine is also used to associated treatment for these conditions: Cardiovascular Events, Diabetic Nephropathy, Heart Failure, High Blood Pressure (Hypertension)

How Pritor/Amlodipine works

Telmisartan interferes with the binding of angiotensin II to the angiotensin II AT₁-receptor by binding reversibly and selectively to the receptors in vascular smooth muscle and the adrenal gland. As angiotensin II is a vasoconstrictor, which also stimulates the synthesis and release of aldosterone, blockage of its effects results in decreases in systemic vascular resistance. Telmisartan does not inhibit the angiotensin converting enzyme, other hormone receptors, or ion channels. Studies also suggest that telmisartan is a partial agonist of PPARγ, which is an established target for antidiabetic drugs. This suggests that telmisartan can improve carbohydrate and lipid metabolism, as well as control insulin resistance without causing the side effects that are associated with full PPARγ activators.

Dosage

Pritor/Amlodipine dosage

Hypertension: Usual dose is 5 mg once daily. The maximum dose is 10 mg once daily. Elderly patients with hepatic insufficiency may be started on 2.5 mg once daily; this dose may also be used when adding Amlodipine to other antihypertensive therapy.Angina (Chronic stable or Vasospastic): 5 to 10 mg, using the lower dose for elderly and in patients with hepatic insufficiency. Most patients require 10 mg.Administrations: May be taken without regard to meals.

Hypertension: Dosage must be individualized. The usual starting dose of Telmisartan tablets is 40 mg once a day. Blood pressure response is dose-related over the range of 20 to 80 mg

Most of the antihypertensive effect is apparent within 2 weeks and maximal reduction is generally attained after 4 weeks. When additional blood pressure reduction beyond that achieved with 80 mg Telmisartan is required, adiuretic may be added.

No initial dosage adjustment is necessary for elderly patients or patients with renal impairment, including those on hemodialysis. Patients ondialysismay develop orthostatic hypotension; their blood pressure should be closely monitored.

Cardiovascular Risk Reduction: The recommended dose of Telmisartan tablets is 80 mg once a day and can be administered with or without food. It is not known whether doses lower than 80 mg of telmisartan are effective in reducing the risk of cardiovascular morbidity and mortality.

When initiating Telmisartan therapy for cardiovascular risk reduction, monitoring of blood pressure is recommended, and if appropriate, adjustment of medications that lower blood pressure may be necessary.

Telmisartan tablets may be administered with other antihypertensive agents with or without food.

Side Effects

The most common adverse effects of amlodipine are associated with vasodilatory action, such as dizziness, flushing, headache, hypotension and peripheral edema. Gastrointestinal disturbances, increased micturition frequency, lethargy, eye pain and mental depression may also occur. A paradoxical increase in ischaemic chest pain may occur at the start of the treatment and in a few patients excessive fall in blood pressure has led to cerebral or myocardial ischaemia or transient blindness. Rashes, fever and abnormalities in liver function due to hypersensitivity reaction of Amlodipine may occur.

Most people tolerate telmisartan well. Side effects are usually minor and either require no treatment or can easily be treated by physician. The most common telmisartan side effects include-Upper respiratory infection such as the common cold or flu up to 7 percent of people, Back pain up to 3 percent of people, Diarrhea up to 3 percent of people, Inflammation of the sinuses up to 3 percent of people.

Toxicity

Intravenous LD₅₀ in rats is 150-200 mg/kg in males and 200 to 250 mg/kg in females. Acute oral toxicity is low: no deaths and no changes occurred in rats or dogs at 2000 mg/kg, the highest dose tested. Limited data are available with regard to overdosage in humans. The most likely manifestations of overdosage with telmisartan would be hypotension, dizziness and tachycardia; bradycardia could occur from parasympathetic (vagal) stimulation.

Precaution

Precaution should be taken in patients with hepatic impairment and during pregnancy and breast feeding.

Use of drugs that act on the renin-angiotensin system during the second and third trimesters of pregnancy reduces fetal renal function and increases fetal and neonatal morbidity and death. Telmisartan may potentially cause extreme low blood pressure or a decrease in kidney function. Hyperkalemia may occur in patients on ARBs, particularly in patients with advanced renal impairment, heart failure, on renal replacement therapy or on potassium supplements, potassium-sparing diuretics, potassium containing salt substitutes or other drugs that increase potassium levels.

Interaction

Drug Interactions- Potentially hazardous interactions: Little or no data are available in patients with markedly impaired cardiac left ventricular function; however, as with other calcium antagonist drugs, the combination of Amlodipine and p-blockers should be avoided in such patients. Other Significant Interactions- Digoxin: Absence of any interaction between Amlodipine and Digoxin in healthy volunteers has been documented in a controlled clinical study. Cimetidine: An unpublished clinical study indicated no interaction between, Amlodipine and Cimetidine in healthy volunteers. Warfarin: An unpublished clinical study in healthy volunteers indicates that Amlodipine did not significantly alter the effect of Warfarin on prothrombin time. Food: Food does not alter the rate or extent of absorption of Amlodipine.

When certain medicines are taken together, there is a possibility of developing drug interactions. With Telmisartan, drugs such as potassium supplements or potassium-sparing diuretics may cause an interaction. When Telmisartan was co-administered with digoxin, median increases in digoxin peak plasma concentration (49%) and in through concentration (20%) where observed. Therefore, monitor digoxin levels when initiating, adjusting and discontinuing Telmisartan for the purpose of keeping the digoxin level within the therapeutic range. NSAID use may lead to increase risk of renal impairment and loss of antihypertensive effect. Monitor renal function periodically in patients receiving Telmisartan and NSAID therapy.

Volume of Distribution

500 L

Elimination Route

Absolute bioavailability depends on dosage. Food slightly decreases the bioavailability (a decrease of about 6% is seen when the 40-mg dose is administered with food).

Half Life

Bi-exponential decay kinetics with a terminal elimination half-life of approximately 24 hours.

Clearance

>800 mL/min

Elimination Route

Following either intravenous or oral administration of 14C-labeled telmisartan, most of the administered dose (>97%) was eliminated unchanged in feces via biliary excretion; only minute amounts were found in the urine (0.91% and 0.49% of total radioactivity, respectively).

Pregnancy & Breastfeeding use

Pregnancy Category C. There are no adequate and well-controlled studies of Amlodipine in pregnant women. Amlodipine should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. It is not known whether Amlodipine is excreted in human milk. In the absence of this information, it is recommended that nursing be discontinued while Amlodipine is administered.

Telmisartan has been assigned to pregnancy categories C (use during first trimester) by the FDA. When pregnancy is detected or expected, Telmisartan should be discontinued as soon as possible. The use of drugs that act directly on the RAA system during the second and third trimesters has been associated with fetal and neonatal injury, including hypotension, neonatal skull hypoplasia, anuria, reversible or irreversible renal failure and death. There are no data on the excretion of Telmisartan into human milk, due to the potential for serious adverse effects in the nursing infant, a decision should be made to discontinue nursing or discontinue the drug.

Contraindication

Hypersensitivity to dihydropyridine derivatives. Pregnant woman.

Telmisartan is contraindicated in conditions like Pregnancy, Adjunct in treatment of opioid dependence, Dry or painful cough. Telmisartan is also contraindicated in patients with known hypersensitivity to telmisartan.

Special Warning

Children with hypertension from 6 years to 17 years of age: 2.5 mg once daily as a starting dose, up-titrated to 5 mg once daily if blood pressure goal is not achieved after 4 weeks. Doses in excess of 5 mg daily have not been studied in pediatric patients.Children under 6 years old: The effect of amlodipine on blood pressure in patients less than 6 years of age is not known.Elderly: Amlodipine used at similar doses in elderly or younger patients is equally well tolerated. Normal dosage regimens are recommended in the elderly, but increase of the dosage should take place with care.Renal impairment: Changes in amlodipine plasma concentrations are not correlated with degree of renal impairment, therefore the normal dosage is recommended. Amlodipine is not dialysable.Hepatic impairment: Dosage recommendations have not been established in patients with mild to moderate hepatic impairment; therefore dose selection should be cautions and should start at the lower end of the dosing range. The pharmacokinetics of Amlodipine have not been studied in severe hepatic impairment. Amlodipine should be initiated at the lowest dose (2.5 mg once daily) and titrated slowly in patients with severe hepatic impairment.

Renal Impairment: Severe impairment or on haemodialysis: Initially, 20 mg once daily.

Hepatic Impairment: Mild to moderate: Max: 40 mg once daily. Severe: Contraindicated.

Acute Overdose

Symptoms: Available data suggest that large overdosage could result in excessive peripheral vasodilatation and possibly reflex tachycardia. Marked and probably prolonged systemic hypotension up to and including shock with fatal outcome have been reported.Management: Clinically significant hypotension due to amlodipine overdosage calls for active cardiovascular support including frequent monitoring of cardiac and respiratory function, elevation of extremities, and attention to circulating fluid volume and urine output. A vasoconstrictor may be helpful in restoring vascular tone and blood pressure, provided that there is no contraindication to its use. Intravenous calcium gluconate may be beneficial in reversing the effects of calcium channel blockade. Gastric lavage may be worthwhile in some cases. In healthy volunteers the use of charcoal up to 2 hours after administration of amlodipine 10 mg has been shown to reduce the absorption rate of amlodipine. Since amlodipine is highly protein-bound, dialysis is not likely to be of benefit.

Symptoms: Hypotension, bradycardia, tachycardia, dizziness, acute renal failure and elevated serum creatinine.

Management: Supportive and symptomatic treatment. Induction of emesis and/or gastric lavage. Activated charcoal may be useful. Salt and volume replacement should be given immediately if hypotension occurs and place patient in supine position.