Navafil Tablet 50 mg
Navafil Tablet 50 mg Uses, Dosage, Side Effects, Food Interaction and all others data.
Navafil Tablet 50 mg is a selective phosphodiesterase 5 (PDE5) enzyme inhibitor used for the treatment of erectile dysfunction caused by diabetes, age induced oxidative stress or other complications. Navafil Tablet 50 mg inhibits the cGMP specific phosphodiesterase type 5 (PDE5) which is responsible for degradation of cGMP in the corpus cavernosum located around the penis. Penile erection during sexual stimulation is caused by increased penile blood flow resulting from the relaxation of penile arteries and corpus cavernosal smooth muscle. This response is mediated by the release of nitric oxide (NO) from nerve terminals and endothelial cells, which stimulates the synthesis of cGMP in smooth muscle cells. Cyclic GMP causes smooth muscle relaxation and increased blood flow into the corpus cavernosum. The inhibition of phosphodiesterase type 5 (PDE5) by avanafil enhances erectile function by increasing the amount of cGMP.
Navafil Tablet 50 mg is a strong competitive inhibitor of phosphodiesterase 5 (PDE5) with a demonstrated in vitro IC50 of 5.2 nM. Its inhibitory effects on PDE5 are 100-fold more potent than on PDE6 and >1000-fold more potent than on other PDE enzymes, meaning it is less likely to cause visual disturbances and cardiovascular adverse effects when compared with less selective PDE5 inhibitors such as sildenafil and vardenafil. It has a relatively quick onset of action allowing for administration as early as 15 minutes prior to sexual activity.
PDE5 inhibitors like avanafil can cause significant drug interactions when administered alongside certain antihypertensive agents (e.g. alpha blockers, substantial amounts of alcohol). PDE5 inhibitors have also been associated with the development of non-arteritic anterior ischemic optic neuropathy (NAION), a rare condition that typically presents as sudden loss of vision in one or both eyes and appears to be more common in patients with a "crowded" optic disc. Patients presenting with any degree of vision loss should immediately discontinue use of all PDE5 inhibitors and seek medical attention. In some jurisdictions, a history of NAION or other degenerative retinal disorders is considered a contraindication to avanafil therapy.
| Trade Name | Navafil Tablet 50 mg |
| Availability | Prescription only |
| Generic | Avanafil |
| Avanafil Other Names | Avanafil, Avanafilo |
| Related Drugs | sildenafil, tadalafil, Viagra, Cialis, alprostadil, Levitra |
| Weight | 50 mg |
| Type | Tablet |
| Formula | C23H26ClN7O3 |
| Weight | Average: 483.951 Monoisotopic: 483.17856544 |
| Protein binding | Avanafil and its two major metabolites, M4 and M16, are highly protein-bound in plasma at approximately 99%, 97%, and 81%, respectively. Binding occurs primarily to albumin (99%), with smaller contributions from γ-globulin (43%) and α1-acid glycoprotein (66%). |
| Groups | Approved |
| Therapeutic Class | Drugs for Erectile Dysfunction |
| Manufacturer | Delta Pharma Ltd. |
| Available Country | Bangladesh |
| Last Updated: | October 19, 2023 at 6:27 am |
Uses
Navafil Tablet 50 mg is a phosphodiesterase 5 (PDE5) inhibitor used for the treatment of erectile dysfunction
Navafil Tablet 50 mg is also used to associated treatment for these conditions: Erectile Dysfunction
How Navafil Tablet 50 mg works
Navafil Tablet 50 mg inhibits the cGMP-specific phosphodiesterase type 5 (PDE5) which is responsible for the degradation of cGMP in the corpus cavernosum located around the penis. Sexual arousal results in the local release of nitric oxide, which in turn stimulates the enzyme guanylate cyclase to produce cGMP. Elevated levels of cGMP result in local smooth muscle relaxation and increased blood flow to the penis (i.e. an erection).
As PDE5 inhibitors like avanafil require the endogenous release of nitric oxide in order to exert their pharmacologic effect, they have no effect on the user in the absence of sexual stimulation/arousal.
Dosage
Navafil Tablet 50 mg dosage
For most patients, the starting dose is 100 mg taken approximately 30 minutes before sexual activity, on an as needed basis.Navafil Tablet 50 mg may be taken with or without food. Take Navafil Tablet 50 mg no more than once a day.
The dose may be increased to 200 mg or decreased to 50 mg based on efficacy and/or tolerability. Use the lowest dose that provides benefit.
Do not use Navafil Tablet 50 mg with strong CYP3A4 inhibitors. If taking a moderate CYP3A4 inhibitor, the dose should be no more than 50 mg in a 24-hour period. In patients on stable alpha-blocker therapy, the recommended starting dose of Navafil Tablet 50 mg is 50 mg.
Side Effects
Most common adverse reactions (greater than or equal to 2%) include headache, flushing, nasal congestion, nasopharyngitis, and back pain
Toxicity
Experience with avanafil overdose is limited. Single doses of up to 800mg and repeat doses of up to 300mg have been administered - these patients experienced adverse effects similar to those seen at therapeutic doses but with increased incidence and severity. Patients experiencing an overdosage of avanafil should be treated with standard symptomatic and supportive measures. Dialysis is unlikely to be of benefit in cases of overdose as avanafil is highly protein-bound in plasma.
Precaution
Patients should not use Navafil Tablet 50 mg if sexual activity is inadvisable due to cardiovascular status or any other reason.
Use of Navafil Tablet 50 mg with alpha-blockers, other antihypertensives, or substantial amounts of alcohol (greater than 3 units) may lead to hypotension.
Patients should seek emergency treatment if an erection lasts greater than 4 hours.
Patients should stop Navafil Tablet 50 mg and seek medical care if a sudden loss of vision occurs in one or both eyes, which could be a sign of Non Arteritic Ischemic Optic Neuropathy (NAION). Discuss with patients the increased risk of NAION in patients with a history of NAION.
Patients should stop taking Navafil Tablet 50 mg and seek prompt medical attention in the event of sudden decrease or loss of hearing.
Interaction
Navafil Tablet 50 mg can potentiate the hypotensive effect of nitrates, alphablockers, antihypertensives, and alcohol. CYP3A4 inhibitors (e.g., ketoconazole, ritonavir, erythromycin) increase Navafil Tablet 50 mg exposure.
Food Interaction
- Avoid excessive or chronic alcohol consumption. Substantial alcohol consumption (e.g. >3 units) in combination with avanafil may increase the risk of hypotension.
- Take with or without food. High-fat meals slow absorption, but not to a clinically significant extent.
[Moderate] GENERALLY AVOID: Additive hypotensive effects may occur when phosphodiesterase-5 (PDE5) inhibitors are used with alcohol, as both are mild systemic vasodilators.
In clinical pharmacology studies, more subjects administered alcohol at a dose of 0.7 g There were reports of postural dizziness, and orthostatic hypotension was observed in some. When tadalafil 20 mg was administered with alcohol at a lower dose of 0.6 g Neither tadalafil nor alcohol affected the plasma concentrations of the other. Administration of avanafil 200 mg with alcohol at a dose of 0.5 g The plasma concentrations of alcohol were not affected. Sildenafil 50 mg and vardenafil 20 mg reportedly did not potentiate the hypotensive effect of alcohol in healthy volunteers with mean maximum blood alcohol levels of 0.08% and in healthy volunteers administered alcohol at a dose of 0.5 g Alcohol and vardenafil plasma levels were not altered when dosed simultaneously. However, the interaction has not been studied. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruit. It may also be appropriate to avoid consuming large amounts of grapefruit juice. Some authorities advise that grapefruit juice should be avoided within 24 hours prior to taking avanafil.
GENERALLY AVOID: Coadministration with grapefruit juice is likely to increase the plasma concentrations of avanafil, which is primarily metabolized by CYP450 3A4.
MANAGEMENT: Patients taking avanafil should avoid consuming large amounts of alcohol, which may increase the potential for orthostatic signs and symptoms including increase in heart rate, decrease in standing blood pressure, dizziness, and headache.
Navafil Tablet 50 mg Drug Interaction
Major: vardenafil, sildenafilModerate: arginine, metoprolol, metoprololUnknown: 5-hydroxytryptophan, charcoal, umeclidinium / vilanterol, anastrozole, aspirin, ipratropium, amoxicillin / clavulanate, rosuvastatin, sodium iodide, acetaminophen, tiotropium, cyanocobalamin, ascorbic acid, cholecalciferol, menaquinone
Navafil Tablet 50 mg Disease Interaction
Major: cardiovascular disease, renal dysfunctionModerate: priapism, alcoholism, hearing loss, liver disease, retinitis pigmentosa, seizure disorders
Volume of Distribution
The apparent volume of distribution of avanafil is 47 to 83 L.
Elimination Route
Navafil Tablet 50 mg is rapidly absorbed following oral administration (Tmax of 30-45 minutes) and appears to have low to moderate oral bioavailability, though formal studies have not been conducted. Administration with a meal results in a mean delay in Tmax of 1.12 to 1.25 hours, a 39% mean reduction in Cmax, and a negligible effect on AUC.
Half Life
Studies have demonstrated variability in the terminal elimination half-life of avanafil, with estimates ranging between 5 - 17 hours.
Elimination Route
Following oral administration, avanafil is extensively metabolized. Approximately 62% of a given dose is excreted as metabolites in the feces and approximately 21% as metabolites in the urine.
Pregnancy & Breastfeeding use
Pregnancy Category C. Navafil Tablet 50 mg is not indicated for use in women. There are no adequate and well-controlled studies of Navafil Tablet 50 mg in pregnant women.
Contraindication
Administration of Navafil Tablet 50 mg to patients using any form of organic nitrate is contraindicated. Hypersensitivity to any component of the Navafil Tablet 50 mg tablet
Special Warning
Pediatric Use: STENDRA is not indicated for use in pediatric patients. Safety and efficacy in patients below the age of 18 years has not been established.
Geriatric Use: Of the total number of subjects in clinical studies of avanafil, approximately 23% were 65 and over. No overall differences in efficacy and safety were observed between subjects over 65 years of age compared to younger subjects; therefore no dose adjustment is warranted based on age alone. However, a greater sensitivity to medication in some older individuals should be considered.
Renal & hepatic impairment patients: Do not use in patients with severe renal & hepatic impairment
Acute Overdose
Single doses up to 800 mg have been given to healthy subjects, and multiple doses up to 300 mg have been given to patients. In cases of overdose, standard supportive measures should be adopted as required. Renal dialysis is not expected to accelerate clearance because avanafil is highly bound to plasma proteins and is not significantly eliminated in the urine.
Storage Condition
Store at 20-25°C
Innovators Monograph
You find simplified version here Navafil Tablet 50 mg
Navafil Tablet 50 mg contains Avanafil see full prescribing information from innovator Navafil Tablet 50 mg Monograph, Navafil Tablet 50 mg MSDS, Navafil Tablet 50 mg FDA label
