NEPRIVAS 49/51

Indications

• Hypertension
• Heart failure
• Prevention of cardiovascular events in patients with established atherosclerotic cardiovascular disease

Dosage

Children: For neonates, 250–500 micrograms/kg every 8–12 hours, increased if necessary to 2–3

Adults: Initially 80 mg once daily, increased if necessary up to a maximum of 320 mg daily, based on clinical response.

Mechanism of action

Valsartan selectively binds to angiotensin receptor 1 (AT1), preventing angiotensin II from exerting its hypertensive effects, such as vasoconstriction and aldosterone secretion. This blockade results in reduced blood pressure, lower aldosterone levels, decreased cardiac activity, and increased sodium excretion. Additionally, valsartan modulates the renin-angiotensin-aldosterone system (RAAS), which is critical in cardiovascular and kidney function regulation.

Pharmacodynamics

Valsartan inhibits the hypertensive effects of angiotensin II, with an oral dose of 80 mg achieving approximately 80% inhibition of the pressor effect at peak, and about 30% inhibition persisting for 24 hours. It minimally affects plasma aldosterone levels and does not significantly alter total cholesterol, triglycerides, serum glucose, or uric acid levels. Hypotension is rare, but caution is advised in patients with an activated renin-angiotensin system, such as those on high-dose diuretics or with heart failure.

Pharmacokinetics

Valsartan is well absorbed after oral administration, with peak plasma concentrations occurring within 2 to 4 hours. It has an elimination half-life of approximately 6 hours, with a bioavailability of around 25% due to first-pass metabolism. Valsartan is primarily eliminated via the feces and to a lesser extent through urine, with renal impairment not significantly affecting its pharmacokinetics.

Contra-indications

• Biliary obstructive disorders
• Cholestasis

Adverse effects

• Anaemia
• Arrhythmias
• Chest pain
• Cystitis
• Depression
• Dyspnoea
• Flatulence
• Gastrointestinal disturbances
• Interstitial lung disease
• Liver disorder
• Pain in extremities
• Sepsis
• Taste alteration
• Tendon pain
• Visual impairment

Interactions

• Taxanes (unknown effect on exposure)

Precautions

• Caution in patients with heart failure
• Monitor for symptomatic hypotension in patients with activated renin-angiotensin system
• Adjust dose in hepatic impairment
• Initial lower doses in renal impairment

Pregnancy

Use only if potential benefit justifies potential risk to the fetus. Contraindicated in the second and third trimesters due to potential harm.

Breast-feeding

Not recommended due to potential adverse effects on the infant.

Storage

Store at room temperature, away from moisture and heat.

Formulations

• Valsartan 40 mg capsules
• Valsartan 80 mg capsules
• Oral suspension

Indications

• Constipation
• Dietary fiber supplementation
• Irritable bowel syndrome
• Diverticular disease
• Weight management

Dosage

Children: Refer to appropriate guidelines for specific dosage; generally taken with adequate fluid intake.

Adults: Refer to appropriate guidelines for specific dosage; generally taken with adequate fluid intake.

Mechanism of action

Cellulose acts primarily as a bulk-forming laxative. It absorbs water in the intestines, which increases stool bulk and stimulates peristalsis, thus facilitating bowel movements. Additionally, cellulose is not digestible by human enzymes, leading to fermentation by gut bacteria, which may enhance gut health and alter gut microbiota composition.

Pharmacodynamics

Cellulose increases stool weight and frequency of bowel movements. It works by retaining water in the intestines, leading to softer stools and improved passage through the gastrointestinal tract. The bulking effect of cellulose can help alleviate constipation and promote overall digestive health. It may also play a role in cholesterol reduction and glycemic control through its effects on digestion and absorption of nutrients.

Pharmacokinetics

Cellulose is not absorbed into the bloodstream due to its indigestible nature. Instead, it passes through the gastrointestinal tract, where it adds bulk to the stool. Its fermentation by colonic bacteria produces short-chain fatty acids, which may have beneficial effects on colon health. The onset of action for cellulose as a laxative can vary but is generally within 24 to 72 hours after ingestion.

Adverse effects

• Bloating
• Flatulence
• Diarrhea
• Abdominal discomfort

Precautions

• Use with caution in patients with a history of gastrointestinal disorders.
• Monitor for potential allergic reactions in sensitive individuals.

Pregnancy

Cellulose is generally considered safe during pregnancy as it is a non-toxic, indigestible fiber.

Breast-feeding

Cellulose is also considered safe during breastfeeding; it is excreted in breast milk in negligible amounts.

Storage

Store in a cool, dry place away from direct sunlight.

Formulations

• Powder
• Capsules
• Tablets
• Granules

Indications

• Hypovolemic shock
• Severe burns
• Postoperative fluid replacement
• Sepsis
• Trauma management

Dosage

Children: Refer to established guidelines for specific dosing, as it varies based on the type of colloidal solution used and the clinical condition being treated.

Adults: Refer to established guidelines for specific dosing, as it varies based on the type of colloidal solution used and the clinical condition being treated.

Mechanism of action

Colloidal solutions work by maintaining oncotic pressure in the blood, thus helping to retain fluid within the vascular system. This is primarily due to the large molecular weight of the colloidal particles, which cannot easily pass through capillary walls. The presence of colloids in the blood helps to draw water into the circulation, increasing blood volume and improving tissue perfusion.

Pharmacodynamics

The pharmacodynamics of colloidal solutions are centered on their ability to exert osmotic pressure, which helps maintain blood volume and pressure. This effect is particularly important in conditions such as hypovolemia and shock, where fluid replacement is necessary to restore hemodynamic stability. The efficacy of colloidal solutions can vary depending on the type of colloid used, as well as the underlying clinical condition being treated.

Pharmacokinetics

Colloidal solutions are typically administered intravenously and their pharmacokinetics can vary based on the specific formulation. Generally, colloids are distributed throughout the vascular compartment and have a longer duration of action compared to crystalloids, as they remain in circulation longer. The elimination of colloids is primarily through the reticuloendothelial system, where they are metabolized or eliminated by the liver and spleen. Factors such as particle size and composition can influence their distribution and clearance.

Adverse effects

• Allergic reactions
• Injection site reactions
• Nausea
• Vomiting
• Headache
• Fever

Precautions

• Use with caution in patients with known allergies to any component of the formulation
• Monitor for signs of hypersensitivity during administration
• Consider volume overload in patients with cardiac or renal impairment

Pregnancy

The safety of colloidal solutions during pregnancy has not been established. Use only if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

It is not known whether colloidal solutions are excreted in human milk. Caution should be exercised when administering to breastfeeding mothers.

Storage

Store at room temperature, protect from light, and do not freeze. Keep out of reach of children.

Formulations

• Colloidal silver
• Colloidal gold
• Colloidal iron
• Other metal colloids

Indications

• Used as a disintegrant in tablet formulations
• Enhances the bioavailability of active pharmaceutical ingredients

Dosage

Children: Refer to the specific formulation guidelines, as dosage will vary based on the active ingredient and formulation type.

Adults: Refer to the specific formulation guidelines, as dosage will vary based on the active ingredient and formulation type.

Mechanism of action

Croscarmellose sodium works by swelling and absorbing water when it comes into contact with gastrointestinal fluids. This swelling leads to the rapid disintegration of the tablet or capsule matrix, facilitating the release and absorption of the active pharmaceutical ingredients.

Pharmacodynamics

Croscarmellose sodium is classified as a superdisintegrant. Its ability to rapidly disintegrate solid dosage forms can significantly enhance the dissolution rate of the active ingredient, which is crucial for achieving therapeutic effects in a timely manner.

Pharmacokinetics

Croscarmellose sodium is not absorbed in the gastrointestinal tract and does not exert pharmacological effects in the body. It is considered non-toxic and is excreted unchanged. Its main role is as an excipient, influencing the formulation's characteristics rather than the pharmacokinetics of the active ingredients.

Precautions

• Use with caution in patients with known hypersensitivity to croscarmellose or its components.

Pregnancy

Safety in pregnancy has not been established. Use only if clearly needed.

Breast-feeding

Caution is advised when using during breastfeeding, as safety has not been established.

Storage

Store in a cool, dry place, away from moisture and heat.

Formulations

• Powder
• Granules

Indications

• Used as an excipient in solid dosage forms
• Facilitates drug disintegration and dissolution

Dosage

Children: Refer to specific product formulation guidelines as crospovidone is used as an excipient and does not have a direct dosage.

Adults: Refer to specific product formulation guidelines as crospovidone is used as an excipient and does not have a direct dosage.

Mechanism of action

Crospovidone acts by rapidly absorbing water and swelling upon contact with moisture. This action leads to the disintegration of solid dosage forms, thus increasing the surface area of the active ingredients and promoting their dissolution and subsequent absorption in the gastrointestinal tract. It does not affect the pH of the formulation, ensuring that the active ingredients remain stable.

Pharmacodynamics

Crospovidone exhibits properties that enhance the bioavailability of active ingredients in pharmaceutical formulations. Its ability to rapidly disintegrate tablets and capsules leads to quicker release and absorption of the drug into systemic circulation. As a disintegrant, it aids in the effective delivery of drugs that may otherwise be poorly soluble.

Pharmacokinetics

Crospovidone itself is not absorbed systemically when administered orally. It remains in the gastrointestinal tract, where it performs its function as a disintegrant. The pharmacokinetic profile of drugs formulated with crospovidone may be influenced by the enhanced dissolution and absorption rates provided by this excipient.

Pregnancy

Crospovidone is considered to have low toxicity and is generally regarded as safe for use during pregnancy, but specific studies are limited.

Breast-feeding

There is insufficient data on the excretion of crospovidone in human milk, but it is deemed safe for use during breastfeeding.

Storage

Store in a cool, dry place away from light and moisture, in tightly closed containers.

Formulations

• Powder
• Tablets

Indications

• Monitoring respiratory function
• Assessment of metabolic status
• Management of respiratory acidosis
• Management of respiratory alkalosis

Dosage

Children: Dosing for interventions related to carbon dioxide levels in pediatric patients should be guided by clinical protocols and the BNF for Children.

Adults: Dosing for interventions related to carbon dioxide levels is typically based on clinical assessment and individual patient needs. Refer to clinical guidelines for specific scenarios.

Mechanism of action

Carbon dioxide acts primarily as a signaling molecule in the body, influencing respiratory drive and blood pH. It is produced during cellular respiration and is a critical component of the bicarbonate buffering system, which helps maintain acid-base homeostasis. Elevated levels of CO2 in the blood stimulate ventilation in the lungs, increasing the rate of gas exchange and facilitating the removal of excess CO2.

Pharmacodynamics

The pharmacodynamic effects of dioxides, particularly carbon dioxide, are closely related to its concentration in the blood. As CO2 levels increase, it leads to respiratory acidosis, which can stimulate the respiratory centers in the brain to increase ventilation. Conversely, low levels of CO2 can cause respiratory alkalosis, potentially leading to decreased respiratory drive. CO2 also plays a role in vasodilation and can affect blood flow and pressure through its influence on smooth muscle tone.

Pharmacokinetics

Carbon dioxide is produced endogenously during metabolic processes and is transported in the bloodstream primarily in three forms: dissolved in plasma, as bicarbonate ions (HCO3-), and bound to hemoglobin. The half-life of CO2 in the bloodstream is very short due to its rapid exchange with alveolar gas in the lungs. The elimination of CO2 occurs through exhalation, making it a dynamic component of respiratory physiology.

Pregnancy

Data on the effects of dioxide during pregnancy are limited. Caution is advised due to potential risks associated with exposure.

Breast-feeding

Limited data are available regarding the excretion of dioxide in human milk. Caution is recommended.

Storage

Store in a cool, dry place, away from direct sunlight and moisture.

Dosage

Children: Paediatric fluid requirements should be calculated based on age, weight, and clinical condition. Refer to the guidelines in the BNF for Children for detailed recommendations.

Adults: Dosage in litres may vary depending on clinical circumstances, such as fluid resuscitation needs, maintenance fluid requirements, or medication delivery. Refer to clinical guidelines for specific scenarios.

Mechanism of action

Litres do not have a pharmacological mechanism of action as they are a unit of measurement rather than a drug. However, the administration of fluids measured in litres can influence various physiological processes, including hydration status, electrolyte balance, and overall fluid homeostasis in the body.

Pharmacodynamics

As a measurement unit, litres do not exhibit pharmacodynamics. However, the volume of fluid administered can impact the pharmacodynamics of medications that are diluted or delivered in fluid form, affecting the rate of absorption, distribution, metabolism, and excretion of drugs.

Pharmacokinetics

Litres as a unit of volume do not possess pharmacokinetic properties. The pharmacokinetics of a drug may be influenced by the volume of fluid in which it is administered, as this can affect the concentration of the drug in the bloodstream and its subsequent pharmacological effects.

Indications

• Used as an excipient in tablet formulations
• Used as a bulking agent in capsule formulations
• Used in food products as a thickener or stabilizer

Dosage

Children: Refer to specific product guidelines as dosage will depend on the formulation and the active ingredients.

Adults: Refer to specific product guidelines as dosage will depend on the formulation and the active ingredients.

Mechanism of action

Microcrystalline cellulose acts as a non-digestible filler that enhances the flow properties of powders during the manufacturing of tablets and capsules. It does not have a direct pharmacological action on the body but ensures that the active ingredients are effectively delivered to the patient.

Pharmacodynamics

As a non-active ingredient, microcrystalline cellulose does not exert pharmacodynamic effects typical of active pharmaceutical ingredients. Its primary role is to provide a stable and consistent matrix for the drug, facilitating the release of the active compound once ingested.

Pharmacokinetics

Microcrystalline cellulose is not absorbed in the gastrointestinal tract; it passes through the digestive system largely unchanged. It adds bulk to the stool, which may aid in promoting regular bowel movements. The substance is excreted in feces, where it contributes to dietary fiber intake.

Pregnancy

Data regarding the use of microcrystalline cellulose during pregnancy is limited. It is advisable to consult with healthcare professionals before use.

Breast-feeding

Microcrystalline cellulose is considered safe during breastfeeding, as it is not absorbed systemically.

Storage

Store in a cool, dry place away from direct sunlight and moisture.

Indications

• Tablet coating
• Granule coating
• Improvement of drug stability
• Taste masking
• Aesthetic enhancement of pharmaceuticals

Dosage

Children: Dosage will depend on the specific formulation and active ingredients of the medication being coated. Refer to the specific product information for guidance.

Adults: Dosage will depend on the specific formulation and active ingredients of the medication being coated. Refer to the specific product information for guidance.

Mechanism of action

Opadry functions primarily as a coating polymer that adheres to the surface of tablets or granules, creating a protective layer. This layer can control the release of the active ingredient and protect it from environmental factors such as moisture and light. The specific composition of Opadry can vary, but it typically includes film-forming agents, plasticizers, and colorants that work together to achieve the desired coating characteristics.

Pharmacodynamics

The pharmacodynamics of Opadry is largely focused on its physical and chemical properties rather than specific biological interactions. The coating alters the dissolution characteristics of the drug, potentially leading to modified release profiles. This can enhance drug bioavailability or control the release rate of the active ingredient, thereby impacting the therapeutic effect.

Pharmacokinetics

As a coating agent, Opadry itself is not absorbed into the systemic circulation and does not have pharmacokinetic properties related to absorption, distribution, metabolism, or excretion of an active pharmaceutical ingredient. Its impact on pharmacokinetics is indirect, as it affects how the active drug is released and absorbed in the gastrointestinal tract.

Pregnancy

Opadry is a film-coating agent, and specific studies on its effects during pregnancy are not well-documented. Generally, it is advisable to use medications cautiously during pregnancy. Consult a healthcare provider for guidance.

Breast-feeding

Limited data are available regarding the safety of Opadry during breastfeeding. It is recommended to consult a healthcare provider before use.

Storage

Store in a cool, dry place away from direct sunlight and moisture. Keep out of reach of children.

Formulations

• Opadry OY - a coating system for oral solid dosage forms
• Opadry II - a polymer-based coating system for tablet and capsule applications

Dosage

Children: Refer to specific drug formulations and product labels as purified substances can vary widely in their use and dosing.

Adults: Refer to specific drug formulations and product labels as purified substances can vary widely in their use and dosing.

Mechanism of action

The mechanism of action for purified compounds varies widely depending on the specific substance. Generally, purified drugs exert their effects by interacting with specific biological targets, such as receptors, enzymes, or ion channels, leading to a desired therapeutic effect. This interaction can involve binding to receptors to activate or inhibit signaling pathways, modulating enzymatic activity, or altering physiological processes.

Pharmacodynamics

Pharmacodynamics describes the effects of a drug on the body and the relationship between drug concentration and effect. For purified drugs, this can involve dose-response relationships and the time course of their action. The purified form often enhances potency and reduces variability in response among patients, which can lead to more predictable therapeutic outcomes. The overall effect is determined by the drug's affinity for its target, the efficacy of the drug-receptor interaction, and the downstream signaling pathways activated as a result of this interaction.

Pharmacokinetics

Pharmacokinetics involves the absorption, distribution, metabolism, and excretion (ADME) of a drug. For purified substances, absorption can be more efficient due to the absence of impurities that may affect solubility or stability. Distribution may also be enhanced, leading to higher bioavailability. Metabolism can be influenced by the structure of the purified compound, as it may be metabolized more readily by liver enzymes. Excretion typically occurs through the kidneys or liver, depending on the molecular characteristics of the purified drug.

Pregnancy

Consult with a healthcare professional, as the safety of purified forms of medications during pregnancy may vary depending on the specific substance.

Breast-feeding

Consult with a healthcare professional, as the safety of purified forms of medications during breastfeeding may vary depending on the specific substance.

Storage

Store in a cool, dry place, away from light and moisture, and keep out of reach of children.

Indications

• Heart failure with reduced ejection fraction (HFrEF)
• Reduction of cardiovascular death and hospitalization in chronic heart failure patients

Dosage

Adults: The usual recommended dose of sacubitril/valsartan is 49 mg/51 mg taken twice daily. The dose

Mechanism of action

Sacubitril's active metabolite, LBQ657, inhibits neprilysin, a neutral endopeptidase that cleaves natriuretic peptides such as atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP). By inhibiting neprilysin, sacubitril increases the concentrations of these peptides, which leads to vasodilation, natriuresis, and diuresis. Furthermore, when combined with valsartan, it also blocks the action of angiotensin II, resulting in decreased vascular resistance and blood pressure.

Pharmacodynamics

Clinical studies have demonstrated that sacubitril, especially in combination with valsartan, leads to significant increases in natriuresis and urine levels of cGMP. It has been shown to decrease plasma levels of NT-proBNP, aldosterone, and endothelin-1, indicating an overall beneficial effect on heart failure parameters. It has no significant effect on the QTc interval.

Pharmacokinetics

Sacubitril is rapidly converted to its active metabolite LBQ657, which is responsible for its therapeutic effects. It has a half-life of approximately 11 hours. The drug is metabolized primarily by hydrolysis and conjugation, and it is excreted mainly in the urine. The pharmacokinetics may be affected by renal function, necessitating dose adjustments in patients with significant renal impairment.

Contra-indications

• Hypersensitivity to sacubitril, valsartan or any of the excipients
• History of angioedema related to previous treatment with an angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB)
• Concurrent use of ACE inhibitors
• Severe hepatic impairment
• Pregnancy

Adverse effects

• Hypotension
• Hyperkalemia
• Cough
• Dizziness
• Renal impairment
• Angioedema
• Fatigue

Interactions

• ACE inhibitors
• NSAIDs may reduce the antihypertensive effect
• Potassium-sparing diuretics may increase the risk of hyperkalemia
• Lithium levels may increase

Precautions

• Monitor renal function and potassium levels
• Use with caution in patients with a history of angioedema
• Adjust dose in patients with renal impairment
• Risk of hypotension in volume-depleted patients

Pregnancy

Contraindicated due to potential harm to the fetus.

Breast-feeding

Not recommended, as it is not known if sacubitril is excreted in human milk.

Storage

Store at room temperature, away from moisture and heat.

Formulations

• Tablets: 24 mg/26 mg, 49 mg/51 mg, 97 mg/103 mg (sacubitril/valsartan)

Indications

• Wound management
• Silicone implants
• Dermal fillers
• Medical lubricants
• Scar treatment

Dosage

Children: Refer to specific product guidelines for paediatric dosages, as silicone applications vary widely.

Adults: Refer to specific product guidelines for adult dosages, as silicone applications vary widely.

Mechanism of action

Silicones exhibit their effects primarily through their physical properties rather than a specific biochemical mechanism. They form a protective barrier that is hydrophobic, preventing moisture and microbial penetration, which aids in wound healing and reduces the risk of infection. Their flexibility and inertness also allow them to integrate well with biological tissues.

Pharmacodynamics

Silicones are generally inert and do not interact significantly with biological systems. They provide mechanical support, lubricate surfaces, and facilitate healing without eliciting a strong immune response. Their low toxicity and biocompatibility contribute to their favorable pharmacodynamic profile in medical applications.

Pharmacokinetics

Silicones are not absorbed by the body when used in medical applications. They remain at the site of application and do not undergo significant metabolism. Their elimination is largely through physical means, including degradation over time or removal during surgical procedures. The pharmacokinetic properties can vary depending on the specific silicone formulation and application.

Pregnancy

Silicone is generally considered safe for use during pregnancy as it is inert and non-toxic. However, specific products should be evaluated for safety.

Breast-feeding

Silicone is also considered safe during breastfeeding as it does not transfer into milk; however, care should be taken with specific formulations.

Storage

Store in a cool, dry place away from direct sunlight.

Indications

• Used as an excipient in drug formulations
• Pleurodesis for the management of recurrent pleural effusions

Dosage

Children: Refer to specific guidelines for paediatric use, as dosing may differ based on age and clinical condition.

Adults: Refer to specific guidelines for the appropriate dosage in pleurodesis and other applications, as it may vary based on clinical context.

Mechanism of action

Talc exhibits very good absorptive properties, allowing it to absorb moisture and other substances effectively. This characteristic is particularly useful in pharmaceutical formulations, where it may enhance the stability and texture of the drug product.

Pharmacodynamics

Talc's primary pharmacodynamic effect is its ability to act as an inert filler and bulking agent in pharmaceutical preparations. It does not have any intrinsic pharmacological activity but serves to improve the physical properties of formulations, such as flowability and compressibility.

Pharmacokinetics

Talc is not absorbed systemically when used as an excipient or in medical procedures. Its effects are local, and it remains in the site of application, where it functions primarily as a mechanical agent. The pharmacokinetics of talc in the context of its use in pleurodesis involves its ability to promote adhesion of the pleural surfaces, thereby preventing fluid accumulation.

Pregnancy

Talc is classified as a substance with minimal systemic absorption, but safety during pregnancy has not been well established. Consult relevant guidelines.

Breast-feeding

Talc is not expected to be absorbed in significant amounts; however, caution is advised and consult guidelines.

Storage

Store in a cool, dry place, away from direct sunlight.

Pregnancy

No specific data available, consult a healthcare professional.

Breast-feeding

No specific data available, consult a healthcare professional.

Storage

Store in a cool, dry place away from light.

Mechanism of action

Valsartan belongs to the angiotensin II receptor blocker (ARB) family of drugs, which selectively bind to angiotensin receptor 1 (AT1) and prevent angiotensin II from binding and exerting its hypertensive effects. These include vasoconstriction, stimulation and synthesis of aldosterone and ADH, cardiac stimulation, and renal reabsorption of sodium among others. Overall, valsartan's physiologic effects lead to reduced blood pressure, lower aldosterone levels, reduced cardiac activity, and increased excretion of sodium. Valsartan also affects the renin-angiotensin aldosterone system (RAAS), which plays an important role in hemostasis and regulation of kidney, vascular, and cardiac functions. Pharmacological blockade of RAAS via AT1 receptor blockade inhibits negative regulatory feedback within RAAS which is a contributing factor to the pathogenesis and progression of cardiovascular disease, heart failure, and renal disease. In particular, heart failure is associated with chronic activation of RAAS, leading to inappropriate fluid retention, vasoconstriction, and ultimately a further decline in left ventricular function. ARBs have been shown to have a protective effect on the heart by improving cardiac function, reducing afterload, increasing cardiac output and prevent ventricular hypertrophy. The angiotensin-converting enzyme inhibitor (ACEI) class of medications (which includes drugs such as [ramipril], [lisinopril], and [perindopril]) inhibits the conversion of angiotensin I to angiotensin II by inhibiting the ACE enzyme but does not prevent the formation of all angiotensin II. ARB activity is unique in that it blocks all angiotensin II activity, regardless of where or how it was synthesized. Valsartan is commonly used for the management of hypertension, heart failure, and type 2 diabetes-associated nephropathy, particularly in patients who are unable to tolerate ACE inhibitors. ARBs such as valsartan have been shown in a number of large-scale clinical outcomes trials to improve cardiovascular outcomes including reducing risk of myocardial infarction, stroke, the progression of heart failure, and hospitalization. Valsartan also slows the progression of diabetic nephropathy due to its renoprotective effects. Improvements in chronic kidney disease with valsartan include both clinically and statistically significant decreases in urinary albumin and protein excretion in patients diagnosed with type 2 diabetes and in nondiabetic patients diagnosed with chronic kidney disease. Valsartan also binds to the AT2 receptor, however AT2 is not known to be associated with cardiovascular homeostasis like AT1. Valsartan has about 20,000-fold higher affinity for the AT1 receptor than for the AT2 receptor. The increased plasma levels of angiotensin II following AT1 receptor blockade with valsartan may stimulate the unblocked AT2 receptor. Valsartan, a nonpeptide tetrazole derivative, is an angiotensin II type 1 (AT1) receptor antagonist. Valsartan has pharmacologic actions similar to those of losartan; however, unlike losartan, valsartan is not a prodrug and its pharmacologic activity does not depend on hydrolysis in the liver. Valsartan blocks the physiologic actions of angiotensin II, including vasoconstrictor and aldosterone-secreting effects, by selectively inhibiting access of angiotensin II to AT1 receptors within many tissues, including vascular smooth muscle and the adrenal gland. By comparison, angiotensin-converting enzyme (ACE, kininase II) inhibitors block the conversion of angiotensin I to angiotensin II; however, the blockade of angiotensin II production by ACE inhibitors is not complete since the vasopressor hormone can be formed via other enzymes that are not blocked by ACE inhibitors. Because valsartan, unlike ACE inhibitors, does not inhibit ACE, the drug does not interfere with response to bradykinins and substance P; a beneficial consequence is the absence of certain ACE inhibitor-induced adverse effects (e.g., cough),

Pharmacodynamics

Valsartan inhibits the pressor effects of angiotensin II with oral doses of 80 mg inhibiting the pressor effect by about 80% at peak with approximately 30% inhibition persisting for 24 hours. Removal of the negative feedback of angiotensin II causes a 2- to 3-fold rise in plasma renin and consequent rise in angiotensin II plasma concentration in hypertensive patients. Minimal decreases in plasma aldosterone were observed after administration of valsartan. In multiple-dose studies in hypertensive patients, valsartan had no notable effects on total cholesterol, fasting triglycerides, fasting serum glucose, or uric acid. **Hypotension** Excessive hypotension was rarely seen (0.1%) in patients with uncomplicated hypertension treated with valsartan alone. In patients with an activated renin-angiotensin system, such as volume- and/or salt-depleted patients receiving high doses of diuretics, symptomatic hypotension may occur. This condition should be corrected prior to administration of valsartan, or the treatment should start under close medical supervision. Caution should be observed when initiating therapy in patients with heart failure. Patients with heart failure given valsartan commonly have some reduction in blood pressure, but discontinuation of therapy because of continuing symptomatic hypotension usually is not necessary when dosing instructions are followed. In controlled trials in heart failure patients, the incidence of hypotension in valsartan-treated patients was 5.5% compared to 1.8% in placebo-treated patients. If excessive hypotension occurs, the patient should be placed in the supine position and, if necessary, given an intravenous infusion of normal saline. A transient hypotensive response is not a contraindication to further treatment, which usually can be continued without difficulty once the blood pressure has stabilized. **Impaired Renal Function** Changes in renal function including acute renal failure can be caused by drugs that inhibit the renin-angiotensin system and by diuretics. Patients whose renal function may depend in part on the activity of the renin-angiotensin system (e.g., patients with renal artery stenosis, chronic kidney disease, severe congestive heart failure, or volume depletion) may be at particular risk of developing acute renal failure on valsartan. Monitor renal function periodically in these patients. Consider withholding or discontinuing therapy in patients who develop a clinically significant decrease in renal function on valsartan. **Hyperkalemia** Some patients with heart failure have developed increases in potassium. These effects are usually minor and transient, and they are more likely to occur in patients with pre-existing renal impairment. Dosage reduction and/or discontinuation of valsartan may be required.

Mechanism of action

Sacubitril's active metabolite, LBQ657 inhibits neprilysin, a neutral endopeptidase that would typically cleave natiuretic peptides, which includes: atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and c-type natriuretic peptide (CNP). ANP and BNP are released under atrial and ventricle stress, which activate downstream receptors leading to vasodilation, natriuresis and diuresis. Under normal conditions, neprilysin breaks down other vasodilating peptides and also vasoconstrictors such as angiotensin I and II, endothelin-1 and peptide amyloid beta-protein. Therefore, the inhibition of neprilysin leads to reduced breakdown and increased concentration of endogenous natriuretic peptides in addition to increased levels of vasoconstricting hormones such as angiotensin II. (However, when combined with valsartan, would result in blocking of angiotensin II to its receptor, preventing the vasoconstrictive effects and resulting in a decrease in vascular resistance and blood pressure.) Cardiovascular and renal effects of sacubitril is a result of the increased levels of peptides that are normally degraded by neprilysin.

Pharmacodynamics

n a 7-day valsartan-controlled study in patients with reduced ejection fraction (HFrEF), administration of sacubitril + valsartan (Entresto) resulted in a significant non-sustained increase in natriuresis, increased urine cGMP, and decreased plasma MR-proANP and NT-proBNP compared to valsartan. In a 21-day study in HFrEF patients, it significantly increased urine ANP and cGMP and plasma cGMP, and decreased plasma NT-proBNP, aldosterone and endothelin-1. In clinical studies, this combination had no effect on QTc interval.

Mechanism of action

It has very good absorptive properties.