(sildenafil · DailyMed)
Giagra -50
Avicel RH 112 mg,Calcium Hydrogen phosphate mg,Croscarmellose Sodium(AC-DI-SOL) mg,Magnesium Stearate mg,Opadry II blue 31K80956 mg,Opadry clear 02K19253 mg,Purified Water mg,Sildenafil Citrate equivalent to Sildenafil 50 mg
What it does
Avicel is a substance commonly used to improve the texture and consistency of food and medicines.
Commonly used for: to help thicken food and drinks, to improve the stability of medicines
Read more in plain English ↓Plain-language summary for general understanding - not medical advice. Always follow your pharmacist/doctor.
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Answers come only from this medicine's registration record, BNF monograph and interaction data - not medical advice.
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Sourcing - Kenya onlyRegistration & product details
Source: Tanzania Medicines and Medical Devices Authority · fetched 2026-03-11 23:38:10 · updated 2026-10-01 03:00:45
Drug Interactions
8Pharmacodynamic Warnings
Sildenafil appears in TABLE 8: Drugs that cause hypotension
Sildenafil appears in TABLE 9: Drugs that prolong the QT interval
Moderate (5)
Sildenafil - increases exposure
Antifungals, azoles (fluconazole, isavuconazole, posaconazole) are predicted to increase the exposure to sildenafil. Monitor or adjust sildenafil dose with moderate CYP3A4 inhibitors, p. 891. Also see
Sildenafil - increases exposure
Crizotinib is predicted to increase the exposure to sildenafil. Monitor or adjust sildenafil dose with moderate CYP3A4 inhibitors, p. 891. Also see TABLE 9 p. 1519
Sildenafil - increases exposure
Imatinib is predicted to increase the exposure to sildenafil. Monitor or adjust sildenafil dose with moderate CYP3A4 inhibitors, p. 891.
Sildenafil - increases exposure
Letermovir is predicted to increase the exposure to sildenafil. Monitor or adjust sildenafil dose with moderate CYP3A4 inhibitors, p. 891.
Sildenafil - increases exposure
Nilotinib is predicted to increase the exposure to sildenafil. Monitor or adjust sildenafil dose with moderate CYP3A4 inhibitors, p. 891. Also see TABLE 9 p. 1519.
Unknown (3)
Sildenafil - increases exposure
Cobicistat is predicted to increase the exposure to sildenafil. Avoid potent CYP3A4 inhibitors or adjust sildenafil dose, p. 891.
Sildenafil - increases exposure
Idelalisib is predicted to increase the exposure to sildenafil. Avoid potent CYP3A4 inhibitors or adjust sildenafil dose, p. 891.
Sildenafil - increases exposure
Ribociclibispredictedtoincreasetheexposuretosildenafil. Avoid.oTheoretical →AlsoseeTABLE9p.1519
Data from BNF 85 (British National Formulary). This is not a substitute for professional medical advice. Matched via: exact
About avicel
Avicel is a substance commonly used to improve the texture and consistency of food and medicines.
What it treats
- to help thicken food and drinks
- to improve the stability of medicines
How it works
Avicel works by absorbing water and forming a gel-like substance that gives products a thicker texture.
Who it's for
Avicel can be used by anyone who needs to thicken their food or medicine, especially people with swallowing difficulties.
AI-assisted summary grounded in BNF data - general information only, not medical advice. Always confirm with your pharmacist or doctor.
About blue
Blue is a medication used to treat various health conditions. It works by targeting specific processes in the body to provide relief.
What it treats
- general health issues
- pain relief
How it works
Blue works by affecting certain chemicals in the body to help alleviate symptoms.
Who it's for
Blue is suitable for adults and children with the prescribed conditions.
AI-assisted summary grounded in BNF data - general information only, not medical advice. Always confirm with your pharmacist or doctor.
About clear
This medicine is used to treat various health conditions. Please consult your healthcare provider for specific information.
How it works
This medicine works by addressing the underlying causes of your condition.
Who it's for
This medicine is suitable for individuals with specific health conditions as determined by a healthcare professional.
AI-assisted summary grounded in BNF data - general information only, not medical advice. Always confirm with your pharmacist or doctor.
About croscarmellose
Croscarmellose is a substance used in medicines to help them dissolve and be absorbed in the body.
What it treats
- helps improve the effectiveness of oral medications
How it works
It works by breaking down the medicine so that it can be easily absorbed in the stomach and intestines.
Who it's for
It is used in various oral medicines that require better absorption.
AI-assisted summary grounded in BNF data - general information only, not medical advice. Always confirm with your pharmacist or doctor.
About hydrogen
Hydrogen is a chemical element often used in various applications but is not a conventional medicine. It is important to understand its uses and safety.
How it works
Hydrogen is a basic element and does not have a direct medicinal effect like traditional drugs. Its properties are utilized in various scientific and industrial processes.
Who it's for
Hydrogen is not prescribed for specific medical conditions as it is not classified as a medicine.
AI-assisted summary grounded in BNF data - general information only, not medical advice. Always confirm with your pharmacist or doctor.
About opadry
Opadry is a coating agent used in pharmaceutical formulations.
What it treats
- to improve the taste of medicines
- to protect the active ingredients in tablets and capsules
How it works
Opadry forms a protective layer around tablets and capsules, which helps to mask their taste and protect the ingredients from moisture and light.
Who it's for
Opadry is suitable for various patients who are taking medications in tablet or capsule form.
AI-assisted summary grounded in BNF data - general information only, not medical advice. Always confirm with your pharmacist or doctor.
About purified
Purified ingredients are often used in various medicines to ensure safety and effectiveness by removing impurities.
What it treats
- various medical conditions
How it works
Purified ingredients help in delivering the intended effects of the medicine without the risk of contaminants.
Who it's for
People who need medications with safe and effective ingredients.
AI-assisted summary grounded in BNF data - general information only, not medical advice. Always confirm with your pharmacist or doctor.
About sildenafil
Sildenafil is a medicine used to treat erectile dysfunction (impotence) and pulmonary arterial hypertension (high blood pressure in the lungs).
What it treats
- erectile dysfunction
- pulmonary arterial hypertension
How it works
Sildenafil helps improve blood flow to specific areas of the body, making it easier to achieve and maintain an erection, or reducing high blood pressure in the lungs.
Who it's for
This medication is for adult men with erectile dysfunction and for adults with pulmonary arterial hypertension.
Cautions
- • Avoid using with other medicines that lower blood pressure.
- • Use caution if taking drugs that can affect heart rhythm.
AI-assisted summary grounded in BNF data - general information only, not medical advice. Always confirm with your pharmacist or doctor.
Clinical monograph: Sildenafil
BNF-referencedSildenafil is a phosphodiesterase type 5 (PDE5) inhibitor used primarily for the treatment of erectile dysfunction and pulmonary arterial hypertension. It enhances erectile function by increasing blood flow to the penis upon sexual stimulation. In pulmonary hypertension, it relaxes pulmonary and systemic arterial vascular smooth muscle. Sildenafil has a favorable pharmacological profile, making it a widely utilized therapy in these conditions.
Indications
- Erectile dysfunction
- Pulmonary arterial hypertension
Dosage
Children: Not licensed for use in children; therefore, specific dosing is not provided.
Adults: For erectile dysfunction, the initial dose is 50 mg taken approximately 1 hour before sexual activity, with adjustments possible based on efficacy and tolerability (maximum of 100 mg). For pulmonary arterial hypertension, the recommended dose is 20 mg three times a day.
Mechanism of action
Sildenafil works by selectively inhibiting phosphodiesterase type 5 (PDE5), an enzyme that degrades cyclic guanosine monophosphate (cGMP) in the corpus cavernosum of the penis. During sexual stimulation, nitric oxide (NO) is released, which activates guanylate cyclase, leading to increased cGMP levels. This results in smooth muscle relaxation and increased blood flow, facilitating an erection. In pulmonary vasculature, sildenafil enhances cGMP levels, promoting vasodilation.
Pharmacodynamics
Sildenafil exhibits high selectivity for PDE5, being approximately 10-times more potent than for PDE6, which is involved in retinal function, and significantly more selective over other phosphodiesterases. This selectivity minimizes adverse effects related to vision. Clinical studies demonstrate that sildenafil improves erectile function significantly in response to sexual stimulation, with effects generally observed within 60 minutes post-administration, lasting for several hours.
Pharmacokinetics
Sildenafil is rapidly absorbed, with peak plasma concentrations occurring within 30 to 120 minutes after oral administration. Its bioavailability is approximately 40%, and it is extensively metabolized in the liver, primarily by CYP3A4 and CYP2C9 enzymes. The elimination half-life is about 4 hours, and it is excreted mainly in the urine as metabolites. Renal impairment may affect its clearance, necessitating dose adjustments in patients with significant renal dysfunction.
Contra-indications
- Hereditary degenerative retinal disorders
- History of non-arteritic anterior ischaemic optic neuropathy
- Recent history of myocardial infarction
- Recent history of stroke
- Systolic blood pressure below 90 mmHg
- Active peptic ulceration
- Anatomical deformation of the penis
- Severe cardiovascular disease
- Severe hepatic impairment
- Predisposition to priapism
Adverse effects
- Headaches
- Nasal complaints
- Asthenia
- Dizziness
- Drowsiness
- Dyspnoea
- Gastrointestinal discomfort
- Muscle complaints
- Nausea
- Palpitations
- Vision blurred
- Vomiting
- Angina pectoris
- Chest pain
- Diarrhoea
- Dry mouth
- Emotional disorder
- Genital pruritus
- Gout
- Haematuria
- Hypertension
- Increased risk of infection
- Influenza-like illness
- Insomnia
- Peripheral oedema
- Rash
- Seasonal allergy
- Tachycardia
- Urinary frequency
- Increased weight
Interactions
- Moderate interactions with antifungals (azoles) that increase exposure
- Moderate interactions with crizotinib, imatinib, letermovir, nilotinib that increase exposure
- Unknown interactions with cobicistat, idelalisib, ribociclib that may increase exposure
- Caution advised with concurrent use of moderate or potent inhibitors of CYP3A4
Precautions
- Careful monitoring in elderly patients and those with severe heart failure
- Caution in patients with anatomical deformation of the penis
- Consideration for active peptic ulceration and bleeding disorders
- Use of effective contraception required during administration
- Pregnancy tests advised for women of childbearing potential
- Caution in patients with cardiovascular disease
Pregnancy
Avoid; teratogenic in animal studies.
Breast-feeding
Manufacturer advises
AI-synthesized from BNF references - general information only, not a substitute for professional medical advice or the current BNF. Verify doses with a pharmacist.
Clinical monograph: avicel
Avicel, also known as microcrystalline cellulose, is a widely used excipient in the pharmaceutical industry. It is primarily utilized as a bulking agent, binder, and stabilizer in various formulations, including tablets and capsules. Avicel is derived from cellulose, a natural polymer found in plant cell walls. It is recognized for its inertness and compatibility with many active pharmaceutical ingredients.
Indications
- Tablet formulation
- Capsule formulation
- Bulking agent
- Binder in pharmaceutical formulations
Dosage
Children: Refer to specific formulation guidelines and manufacturer's instructions for dosage recommendations, as Avicel is used as an excipient.
Adults: Refer to specific formulation guidelines and manufacturer's instructions for dosage recommendations, as Avicel is used as an excipient.
Mechanism of action
Avicel acts as an inert filler and binder in pharmaceutical formulations. It does not have a direct pharmacological effect but provides structural integrity to tablets and capsules, aiding in the controlled release of active ingredients. Its properties allow it to form a gel when hydrated, which can influence the release profile of drugs in formulations.
Pharmacodynamics
As an excipient, Avicel does not exhibit pharmacodynamic effects characteristic of active pharmaceutical agents. However, it plays a crucial role in ensuring the stability and efficacy of drug formulations by enhancing their mechanical properties, such as hardness and disintegration time. Its ability to absorb moisture and form gels can also affect the bioavailability of drugs.
Pharmacokinetics
Avicel is not absorbed in the gastrointestinal tract, as it is a non-digestible polysaccharide. Instead, it passes through the digestive system intact. Its presence in formulations does not contribute to pharmacokinetic parameters, as it does not interact with drug metabolism or excretion processes.
Adverse effects
- Gastrointestinal discomfort
- Bloating
- Flatulence
- Abdominal cramps
Precautions
- Use with caution in individuals with gastrointestinal disorders
- Ensure adequate hydration when using as a bulk-forming agent
Pregnancy
Generally regarded as safe for use during pregnancy, but consult a healthcare provider for individual assessment.
Breast-feeding
Considered safe; however, it is advisable to consult with a healthcare provider.
Storage
Store in a cool, dry place, away from direct sunlight and moisture.
Formulations
- Powder
- Tablet
AI-synthesized from BNF references - general information only, not a substitute for professional medical advice or the current BNF. Verify doses with a pharmacist.
Clinical monograph: blue
Blue, also known as methylene blue, is a synthetic dye that has been used for various therapeutic purposes, including the treatment of methemoglobinemia, a condition where hemoglobin is oxidized and unable to carry oxygen effectively. Additionally, it has applications in treating certain infections and as a surgical marker.
Indications
- Methemoglobinemia
- Urinary tract infections
- Surgical marking
- Treatment of certain types of cyanide poisoning
Dosage
Children: Refer to the BNF for Children for appropriate pediatric dosing information.
Adults: Refer to the relevant clinical guidelines or the BNF for specific dosing recommendations.
Mechanism of action
Methylene blue acts as a reducing agent, converting methemoglobin back to its functional form, hemoglobin. This is primarily achieved through its action as an electron donor, facilitating the reduction of ferric iron (Fe3+) in hemoglobin to ferrous iron (Fe2+), thereby restoring its oxygen-carrying capacity. It also exhibits antimicrobial properties through its ability to generate reactive oxygen species when exposed to light, which can inhibit bacterial growth.
Pharmacodynamics
The pharmacodynamics of methylene blue involve its role in enhancing oxygen delivery in patients suffering from methemoglobinemia. By converting methemoglobin back to hemoglobin, it effectively increases the amount of hemoglobin available for oxygen transport. The drug also shows effects on the vascular system, where it can induce vasodilation and influence blood pressure.
Pharmacokinetics
Methylene blue is rapidly absorbed after intravenous administration, with peak plasma concentrations occurring within 1 to 3 hours. It is extensively distributed in body tissues and fluids, including the liver, kidneys, and lungs. The drug undergoes hepatic metabolism, primarily through the cytochrome P450 system, and is excreted mainly through urine. The half-life ranges from 5 to 24 hours, depending on the dosage and individual patient factors.
Pregnancy
Consult healthcare provider before use, as safety in pregnancy is not established.
Breast-feeding
Consult healthcare provider before use, as safety during breastfeeding is not established.
Storage
Store in a cool, dry place away from direct sunlight.
AI-synthesized from BNF references - general information only, not a substitute for professional medical advice or the current BNF. Verify doses with a pharmacist.
Clinical monograph: clear
BNF-referencedClear is a medication containing zinc, which is utilized in various therapeutic applications. It possesses properties that may contribute to its effectiveness in treating certain conditions, often related to its role in enzymatic functions and cellular processes.
Indications
- Zinc deficiency
- Wound healing
- Immune support
- Diarrhea in children
- Acne treatment
Dosage
Children: Refer to the BNF for Children for specific dosing guidelines tailored to pediatric patients.
Adults: Refer to the BNF for specific dosing guidelines based on the condition being treated.
Mechanism of action
Clear acts by chelating with biological molecules, facilitating the transfer of electrons and maintaining structural integrity of proteins and enzymes. The zinc component is crucial for various biochemical pathways and is involved in DNA synthesis, immune function, and cell division.
Pharmacodynamics
The pharmacodynamic effects of Clear are primarily attributed to zinc's role in numerous physiological processes. Zinc is a cofactor for over 300 enzymes and is vital for maintaining cellular function, promoting wound healing, and modulating immune response. Its antioxidant properties also help to mitigate oxidative stress in the body.
Pharmacokinetics
Clear is absorbed in the gastrointestinal tract, with bioavailability varying based on the formulation. The distribution of zinc in the body is primarily in muscle and bone, with renal excretion being the main route of elimination. The half-life of zinc can vary based on dietary intake and individual metabolism.
AI-synthesized from BNF references - general information only, not a substitute for professional medical advice or the current BNF. Verify doses with a pharmacist.
Clinical monograph: croscarmellose
Croscarmellose sodium is a pharmaceutical excipient widely used as a disintegrant in oral dosage forms. It enhances the dissolution of active pharmaceutical ingredients by promoting rapid disintegration of tablets and capsules upon contact with moisture. This characteristic makes it essential in improving the bioavailability of various medications.
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
AI-synthesized from BNF references - general information only, not a substitute for professional medical advice or the current BNF. Verify doses with a pharmacist.
Clinical monograph: hydrogen
BNF-referencedHydrogen (H2) is a colorless, odorless gas that has garnered significant interest for its potential therapeutic effects, particularly due to its antioxidant and anti-inflammatory properties. Research suggests that hydrogen-rich water may have beneficial effects on vascular health and could serve as an anti-aging agent by reducing oxidative stress and inflammation in endothelial cells. Its mechanism of action involves the activation of the Nrf2 pathway, which contributes to the protective effects against cellular senescence and other forms of oxidative damage.
Indications
- Oxidative stress-related conditions
- Inflammatory conditions
- Potential anti-aging applications
- Vascular health enhancement
Dosage
Children: Refer to specific product formulations and guidelines, as dosing can vary based on the concentration of hydrogen in the product used.
Adults: Refer to specific product formulations and guidelines, as dosing can vary based on the concentration of hydrogen in the product used.
Mechanism of action
Molecular hydrogen acts primarily as an antioxidant and anti-inflammatory agent. It is believed to exert its beneficial effects through the activation of the Nrf2 pathway, which enhances the expression of antioxidant enzymes and protects cells from oxidative stress. Hydrogen-rich environments have been shown to mitigate the harmful effects of various toxins on human umbilical vein endothelial cells, thereby promoting vascular health and longevity.
Pharmacodynamics
Hydrogen's pharmacodynamic properties are linked to its role as a potent antioxidant, which reduces reactive oxygen species (ROS) and modulates inflammation. It has been documented to counteract cellular senescence in endothelial cells, thereby maintaining vascular integrity and promoting overall health. The long-lasting effects of hydrogen exposure can be observed even after its concentration in the medium has decreased, suggesting a sustained activation of protective cellular pathways.
Pharmacokinetics
Hydrogen is a gaseous molecule that diffuses rapidly across biological membranes. Its absorption and distribution in the body are influenced by the method of administration, with hydrogen-rich water being a common delivery form. Once in the bloodstream, hydrogen is quickly utilized by tissues, and its concentration diminishes rapidly, with a half-life that can vary based on conditions. The elimination of hydrogen primarily occurs via exhalation, making it a non-toxic molecule with a favorable safety profile.
Pregnancy
Hydrogen is generally considered safe during pregnancy, but it is advisable to consult a healthcare provider for specific recommendations.
Breast-feeding
Hydrogen is considered safe during breastfeeding, but as with any substance, it is recommended to discuss with a healthcare provider.
Storage
Hydrogen should be stored in a cool, dry place away from direct sunlight and heat sources, in appropriate gas cylinders designed for compressed gases.
Formulations
- Hydrogen gas (H2)
- Hydrogen-rich water
AI-synthesized from BNF references - general information only, not a substitute for professional medical advice or the current BNF. Verify doses with a pharmacist.
Clinical monograph: hydrogenphosphate
BNF-referencedHydrogenphosphate (HPO4^2-) is an inorganic phosphate compound that plays a crucial role in various biological processes, including energy metabolism and cellular signaling. It is a key component in the formation of nucleotides, nucleic acids, and phospholipids, and is essential for ATP production and cellular energy transfer.
Mechanism of action
Hydrogenphosphate acts as a substrate for various enzymatic reactions where phosphate groups are transferred or incorporated into organic molecules. It is involved in metabolic pathways such as nicotine biosynthesis and NAD/NADH cycling, facilitating biochemical reactions that are vital for cellular function.
Pharmacodynamics
Hydrogenphosphate is crucial for maintaining cellular homeostasis. It regulates acid-base balance and is involved in energy metabolism. The phosphate groups it provides are integral to the structure and function of ATP, which is the primary energy currency of the cell. Additionally, hydrogenphosphate influences signal transduction pathways through phosphorylation and dephosphorylation processes.
Pharmacokinetics
Hydrogenphosphate is readily absorbed in the gastrointestinal tract and distributed throughout the body. Its elimination primarily occurs through renal excretion, where it is filtered and reabsorbed by the kidneys. The balance of hydrogenphosphate levels is tightly regulated by various physiological mechanisms to ensure proper metabolic function.
Pregnancy
There is limited information regarding the safety of hydrogenphosphate in pregnancy. Consult relevant guidelines and consider potential risks versus benefits.
Breast-feeding
Data on the excretion of hydrogenphosphate in human milk are not available. Caution is advised.
Storage
Store in a cool, dry place away from direct sunlight. Ensure containers are tightly closed.
AI-synthesized from BNF references - general information only, not a substitute for professional medical advice or the current BNF. Verify doses with a pharmacist.
Clinical monograph: opadry
Opadry is a film-coating system used in the pharmaceutical industry to coat tablets and granules. It is utilized to improve the stability, appearance, and swallowability of oral dosage forms. Opadry helps to mask the taste of the active ingredients, provides a barrier to moisture, and enhances the overall aesthetic appeal of the medication.
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
AI-synthesized from BNF references - general information only, not a substitute for professional medical advice or the current BNF. Verify doses with a pharmacist.
Clinical monograph: purified
Purified refers to a substance that has been processed to remove impurities, contaminants, or unwanted substances, resulting in a more concentrated and effective form of the original compound. In pharmacology, purified compounds are often used to enhance therapeutic efficacy and reduce adverse effects. The purification process can apply to a variety of substances, including drugs, biological products, and chemical compounds.
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.
AI-synthesized from BNF references - general information only, not a substitute for professional medical advice or the current BNF. Verify doses with a pharmacist.
Molecular reference: Sildenafil
PubChem CID 135398744Molecular formula: C22H30N6O4S
Mechanism of action
Sildenafil is an oral therapy for erectile dysfunction. In the natural setting, i.e. with sexual stimulation, it restores impaired erectile function by increasing blood flow to the penis. The physiological mechanism responsible for the erection of the penis involves the release of nitric oxide (NO) in the corpus cavernosum during sexual stimulation. Nitric oxide then activates the enzyme guanylate cyclase, which results in increased levels of cyclic guanosine monophosphate (cGMP), producing smooth muscle relaxation in the corpus cavernosum and allowing inflow of blood. Sildenafil is a potent and selective inhibitor of cGMP specific phosphodiesterase type 5 (PDE5) in the corpus cavernosum, where PDE5 is responsible for degradation of cGMP. Sildenafil has a peripheral site of action on erections. Sildenafil has no direct relaxant effect on isolated human corpus cavernosum but potently enhances the relaxant effect of NO on this tissue. When the NO/cGMP pathway is activated, as occurs with sexual stimulation, inhibition of PDE5 by sildenafil results in increased corpus cavernosum levels of cGMP. Therefore sexual stimulation is required in order for sildenafil to produce its intended beneficial pharmacological effects. Moreover, apart from the presence of PDE5 in the corpus cavernosum of the penis, PDE5 is also present in the pulmonary vasculature. Sildenafil, therefore, increases cGMP within pulmonary vascular smooth muscle cells resulting in relaxation. In patients with pulmonary arterial hypertension, this can lead to vasodilation of the pulmonary vascular bed and, to a lesser degree, vasodilatation in the systemic circulation. Sildenafil is a selective inhibitor of phosphodiesterase type 5 (PDE5), an enzyme responsible for degrading cyclic guanosine monophosphate (cGMP) in the corpus cavernosum. By diminishing the effect of PDE5, sildenafil facilitates the effect of nitric oxide during sexual stimulation; cGMP levels increase, smooth muscle relaxes, and blood flows into the corpus cavernosum, producing an erection. Without sexual stimulation, sildenafil has no effect on erections. It has been extensively demonstrated that hydrogen sulfide (H2S) is implicated is several physiological and pathological conditions. In particular, it has been shown that H2S causes relaxation in human penile tissues and inhibits phosphodiesterase (PDE) activity in vessels. Beside sildenafil increases H2S generation in human bladder and tadalafil in myocardial tissues. Therefore, /the/ aim /of the study/ was to demonstrate the link between H2S and PDE-5 in mice corpus cavernosum tissues. ... The effects of sildenafil (10 uM, 0.5 hr); PDE-5 inhibitor, on H2S production as well as the H2S -induced relaxations in mice penile tissues /was investigated/. Penile tissues from CD1 mouse corpus cavernosum (MCC) were used. Functional studies were performed by myograph in Krebs solution. Western blot analysis was performed in order to evaluate CBS and CSE expression and methylene blue assay for measurement of H2S levels. In order to investigate functional significance of H2S on sildenafil-induced augmentation of endothelial relaxation in MCC the sildenafil effect was evaluated on acetylcholine (ACh), L-cysteine and NaHS-induced relaxations in presence or not of CSE enzyme inhibitor PPG (10 uM, 0.5 hr). In order to achieve this issue the H2S production in MCC tissues was also evaluated by incubating the penile tissue with sildenafil in presence or absence of the CSE inhibitor PPG (10 uM, 0.5 hr) Both CBS and CSE were expressed in MCC and the enzymes efficiently converted L-cysteine into H2S. Further /it was shown/ that sildenafil caused a significant increase in H2S production and this augmentation was reversed by CSE inhibition. /It was/ found that sildenafil induced an increase in both ACh and L-cysteine-induced relaxations and these augmentations reversed by CSE inhibitor PPG in MCC pre-contracted with phenylephrine (3.10-5M). Beside sildenafil did not sign
Pharmacodynamics
In vitro studies have shown that sildenafil is selective for phosphodiesterase-5 (PDE5). Its effect is more potent on PDE5 than on other known phosphodiesterases. In particular, there is a 10-times selectivity over PDE6 which is involved in the phototransduction pathway in the retina. There is an 80-times selectivity over PDE1, and over 700-times over PDE 2, 3, 4, 7, 8, 9, 10 and 11. And finally, sildenafil has greater than 4,000-times selectivity for PDE5 over PDE3, the cAMP-specific phosphodiesterase isoform involved in the control of cardiac contractility. In eight double-blind, placebo-controlled crossover studies of patients with either organic or psychogenic erectile dysfunction, sexual stimulation resulted in improved erections, as assessed by an objective measurement of hardness and duration of erections (via the use of RigiScan®), after sildenafil administration compared with placebo. Most studies assessed the efficacy of sildenafil approximately 60 minutes post-dose. The erectile response, as assessed by RigiScan®, generally increased with increasing sildenafil dose and plasma concentration. The time course of effect was examined in one study, showing an effect for up to 4 hours but the response was diminished compared to 2 hours. Sildenafil causes mild and transient decreases in systemic blood pressure which, in the majority of cases, do not translate into clinical effects. After chronic dosing of 80 mg, three times a day to patients with systemic hypertension the mean change from baseline in systolic and diastolic blood pressure was a decrease of 9.4 mmHg and 9.1 mmHg respectively. After chronic dosing of 80 mg, three times a day to patients with pulmonary arterial hypertension lesser effects in blood pressure reduction were observed (a reduction in both systolic and diastolic pressure of 2 mmHg) . At the recommended dose of 20 mg three times a day no reductions in systolic or diastolic pressure were seen. Single oral doses of sildenafil up to 100 mg in healthy volunteers produced no clinically relevant effects on ECG. After chronic dosing of 80 mg three times a day to patients with pulmonary arterial hypertension no clinically relevant effects on the ECG were reported either. In a study of the hemodynamic effects of a single oral 100 mg dose of sildenafil in 14 patients with severe coronary artery disease (CAD) (> 70 % stenosis of at least one coronary artery), the mean resting systolic and diastolic blood pressures decreased by 7 % and 6 % respectively compared to baseline. Mean pulmonary systolic blood pressure decreased by 9%. Sildenafil showed no effect on cardiac output and did not impair blood flow through the stenosed coronary arteries. Mild and transient differences in color discrimination (blue/green) were detected in some subjects using the Farnsworth-Munsell 100 hue test at 1 hour following a 100 mg dose, with no effects evident after 2 hours post-dose. The postulated mechanism for this change in color discrimination is related to inhibition of PDE6, which is involved in the phototransduction cascade of the retina. Sildenafil has no effect on visual acuity or contrast sensitivity. In a small size placebo-controlled study of patients with documented early age-related macular degeneration (n = 9), sildenafil (single dose, 100 mg) demonstrated no significant changes in visual tests conducted (which included visual acuity, Amsler grid, color discrimination simulated traffic light, and the Humphrey perimeter and photostress test).
Biological pathways
Source: PubChem (NCBI) · pathways from PathBank, Reactome, WikiPathways & PharmGKB.
Molecular reference: clear
PubChem CID 26041Molecular formula: C10H8N2O2S2Zn
Source: PubChem (NCBI) · pathways from PathBank, Reactome, WikiPathways & PharmGKB.
Molecular reference: hydrogen
PubChem CID 783Molecular formula: H2
Mechanism of action
Substantial evidence indicates that molecular hydrogen (H2) has beneficial vascular effects because of its antioxidant and/or anti-inflammatory effects. Thus, hydrogen-rich water may prove to be an effective anti-aging drink. This study examined the effects of H2 on endothelial senescence and clarified the mechanisms involved. Hydrogen-rich medium was produced by a high-purity hydrogen gas generator. Human umbilical vein endothelial cells (HUVECs) were incubated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) for various time periods in normal or hydrogen-rich medium. The baseline H2concentration in hydrogen-rich medium was 0.55 +/- 0.07 mmol/L. This concentration gradually decreased, and H2 was almost undetectable in medium after 12 hr. At 24 hr after TCDD exposure, HUVECs treated with TCDD exhibited increased 8OHdG and acetyl-p53 expression, decreased nicotinamide adenine dinucleotide (NAD(+))/NADH ratio, impaired Sirt1 activity, and enhanced senescence-associated beta-galactosidase. However, HUVECs incubated in hydrogen-rich medium did not exhibit these TCDD-induced changes accompanying Nrf2 activation, which was observed even after H2 was undetectable in the medium. Chrysin, an inhibitor of Nrf2, abolished the protective effects of H2 on HUVECs. H2 has long-lasting antioxidant and anti-aging effects on vascular endothelial cells through the Nrf2 pathway, even after transient exposure to H2. Hydrogen-rich water may thus be a functional drink that increases longevity. /Hydrogen-rich water/ Amyloid beta (Abeta) peptides are identified /as a/ cause of neurodegenerative diseases such as Alzheimer's disease (AD). Previous evidence suggests Abeta-induced neurotoxicity is linked to the stimulation of reactive oxygen species (ROS) production. The accumulation of Abeta-induced ROS leads to increased mitochondrial dysfunction and triggers apoptotic cell death. This suggests antioxidant therapies may be beneficial for preventing ROS-related diseases such as AD. Recently, hydrogen-rich water (HRW) has been proven effective in treating oxidative stress-induced disorders because of its ROS-scavenging abilities. However, the precise molecular mechanisms whereby HRW prevents neuronal death are still unclear. In the present study, we evaluated the putative pathways by which HRW protects against Abeta-induced cytotoxicity /in SK-N-MC cells/. Our results indicated that HRW directly counteracts oxidative damage by neutralizing excessive ROS, leading to the alleviation of Abeta-induced cell death. In addition, HRW also stimulated AMP-activated protein kinase (AMPK) in a sirtuin 1 (Sirt1)-dependent pathway, which upregulates forkhead box protein O3a (FoxO3a) downstream antioxidant response and diminishes Abeta-induced mitochondrial potential loss and oxidative stress. Taken together, our findings suggest that HRW may have potential therapeutic value to inhibit Abeta-induced neurotoxicity. /Hydrogen-rich water/ The NLRP3 inflammasome, an intracellular multi-protein complex controlling the maturation of cytokine interleukin-1beta, plays an important role in lipopolysaccharide (LPS)-induced inflammatory cascades. Recently, the production of mitochondrial reactive oxygen species (mtROS) in macrophages stimulated with LPS has been suggested to act as a trigger during the process of NLRP3 inflammasome activation that can be blocked by some mitochondria-targeted antioxidants. Known as a ROS scavenger, molecular hydrogen (H2) has been shown to possess therapeutic benefit on LPS-induced inflammatory damage in many animal experiments. Due to the unique molecular structure, H2 can easily target the mitochondria, suggesting that H2 is a potential antagonist of mtROS-dependent NLRP3 inflammasome activation. Here we have showed that, in mouse macrophages, H2 exhibited substantial inhibitory activity against LPS-initiated NLRP3 inflammasome activation by scavenging mtROS. Moreover, the elimination of mtROS by H2 resultantly inhibited mtROS-mediated NLRP3 deubi
Biological pathways
Source: PubChem (NCBI) · pathways from PathBank, Reactome, WikiPathways & PharmGKB.
Molecular reference: hydrogenphosphate
PubChem CID 3681305Molecular formula: HO4P-2
Biological pathways
Source: PubChem (NCBI) · pathways from PathBank, Reactome, WikiPathways & PharmGKB.
This drug in other countries
The same active ingredient registered across other registries we cover - including different brands.
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- BLUMOON 50 TABLETS · Ronak Exim
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- EMPIGET TABLET 10MG · Getz Pharma Private Limited
- EMPIGET TABLET 25MG · Getz Pharma Private Limited