Anthropometric Measurements as Predictors of Low Birth Weight Among Tanzanian Neonates: A Hospital-Based Study
November 7, 2025
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Brand Name :
Stendra
Synonyms :
avanafil
Class :
Phosphodiesterase-5 Enzyme Inhibitors
Brand Name :
Stendra
Synonyms :
avanafil
Class :
Phosphodiesterase-5 Enzyme Inhibitors
Dosage Forms & Strengths 
Tablet
50mg
100mg
200mg
100
mg
Orally 
up to 15 minutes
before engaging in sexual activity; not to exceed 1 dose per day
The dose may be increased to 200 mg and taken as early as 15 minutes before engaging in sexual activity, or it may be dropped to 50 mg and taken 30 minutes before engaging in sexual activity, depending on each individual's efficacy and tolerability
Use the low effective dosage
Safety and efficacy not established
Refer to adult dosing
may enhance the concentration of serum when combined with avanafil
may enhance the concentration of serum when combined with avanafil
may enhance the concentration of serum when combined with avanafil
may enhance the concentration of serum when combined with avanafil
may enhance the concentration of serum when combined with avanafil
avanafil: they may enhance the serum concentration of CYP3A Inhibitors
avanafil: they may enhance the serum concentration of CYP3A Inhibitors
avanafil: they may enhance the serum concentration of CYP3A Inhibitors
avanafil: they may enhance the serum concentration of CYP3A Inhibitors
avanafil: they may enhance the serum concentration of CYP3A Inhibitors
may enhance the serum concentration of CYP3A4 inhibitors
may enhance the serum concentration of CYP3A4 inhibitors
may enhance the serum concentration of CYP3A4 Inhibitors
may diminish the serum concentration of CYP3A4 inducers
may diminish the serum concentration of CYP3A4 inducers
may diminish the serum concentration of CYP3A4 inducers
may diminish the serum concentration of CYP3A4 inducers
may diminish the serum concentration of CYP3A4 inducers
avanafil: they may diminish the serum concentration of CYP3A4 Inducers
avanafil: they may diminish the serum concentration of CYP3A4 Inducers
May increase the vasodilatory effect when combined with Vasodilators
May increase the vasodilatory effect when combined with Vasodilators
the effect of avanafil is increased by lorlatinib, by altering intestinal or hepatic CYP3A4 enzyme metabolism
when both drugs are combined, there may be an increased effect of avanafil by affecting hepatic or intestinal enzyme cyp3a4 metabolism  
CYP3A strong enhancers of the small intestine may reduce the bioavailability of avanafil
may decrease the serum concentration of CYP3A4 Inducers
amyl nitrite: they may increase the vasodilatory effect when combined with Phosphodiesterase 5 Inhibitors
may enhance the hypotensive effect of Alpha1-Blockers
bunazosin (Not available in the United States)
may enhance the hypotensive effect of Alpha1-Blockers
may enhance the hypotensive effect of Alpha1-Blockers
may enhance the hypotensive effect of Alpha1-Blockers
may enhance the hypotensive effect of Alpha1-Blockers
may enhance the hypotensive effect
may enhance the hypotensive effect
may enhance the hypotensive effect
may enhance the hypotensive effect
may enhance the hypotensive effect
may increase the vasodilatory effect
may increase the vasodilatory effect
may increase the vasodilatory effect
may increase the vasodilatory effect
may increase the vasodilatory effect
may increase the vasodilatory effect
may increase the vasodilatory effect
may increase the vasodilatory effect
Phosphodiesterase 5 Inhibitors: they may increase the hypotensive effect when combined with blood viscosity reducing agents
Phosphodiesterase 5 Inhibitors: they may increase the hypotensive effect when combined with blood viscosity reducing agents
may have an increased hypotensive effect when combined with anti-hypertensive agents
buflomedil may intensify avanafil's hypotensive effects
avanafil: it may increase the therapeutic efficacy of etynodiol
fedratinib increases the effect of avanafil by altering the intestinal/ hepatic CYP3A4 enzyme metabolism
it may increase the risk of adverse effects 
May enhance the effects of the other by pharmacodynamic synergism
May enhances the effects of the other by pharmacodynamic synergism
may enhance the effect of vasodilators
may enhance the effect of vasodilators
may enhance the effect of vasodilators
may enhance the effect of vasodilators
may enhance the effect of vasodilators
may increase the hypotensive effect of Blood Pressure Lowering Agents
may increase the hypotensive effect of Blood Pressure Lowering Agents
when nicorandil is combined or used concurrently with phosphodiesterase 5 inhibitors, it can lead to a decrease in blood pressure, which is called the synergic effect
the metabolism of avanafil may be decreased when combined with danoprevir
the serum levels of avanafil may be increased
Actions and Spectrum:
avanafil is a phosphodiesterase type 5 (PDE5) inhibitor and is used for the treatment of erectile dysfunction (ED) in men. The mechanism of action of avanafil is similar to other PDE5 inhibitors, such as sildenafil, tadalafil, and vardenafil.
It works by inhibiting the PDE5 enzyme, which breaks down cyclic guanosine monophosphate (cGMP), a molecule responsible for relaxing smooth muscle and increasing blood flow to the penis. By inhibiting PDE5, avanafil allows cGMP to accumulate, leading to increased blood flow and resulting in an erection.
Frequency Defined 
>2% 
Flushing (3.5%)
Headache (5.6%)
Nasal congestion (2.1%)
Back pain (2.5%)
Nasopharyngitis (3.4%)
Upper respiratory infection (<2%)
Influenza (<2%)
Bronchitis (<2%)
Sinusitis (<2%)
Hypertension (<2%)
Sinus congestion (<2%)
Dyspepsia (<2%)
Constipation (<2%)
Nausea (<2%)
Black Box Warning
avanafil drug used to treat erectile dysfunction, carries a Black Box Warning regarding the risk of sudden vision loss.
Contraindication/Caution:
Contraindications:
Cautions:
Pregnancy warnings:   
US FDA pregnancy category: C
Lactation:  Safety and efficacy not established
Pregnancy Categories:        
Category A: Studies that were well-controlled and met expectations revealed no risk to the fetus in either the first or second trimester.
Category B: There were lack of studies on pregnant women and no evidence of risk to the foetus in animal experiments.
Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.
Category D: adequate data available with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits.
Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women.
Category N: There is no data available for the drug under this category
Pharmacology: 
avanafil is a phosphodiesterase type 5 (PDE5) inhibitor, a class of drugs used for the treatment of erectile dysfunction (ED). Avanafil works by increasing blood flow to the penis, which helps to produce and maintain an erection.
Pharmacodynamics: 
avanafil works by blocking the action of PDE5, an enzyme that breaks down cyclic guanosine monophosphate (cGMP) in the penis. cGMP is responsible for relaxing the smooth muscles in the penis and allowing blood to flow in and create an erection. By inhibiting PDE5, avanafil increases the levels of cGMP and enhances blood flow to the penis.
Pharmacodynamics: 
It works by inhibiting the activity of phosphodiesterase, an enzyme that is responsible for breaking down cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP). These enzymes play a crucial role in the process of platelet aggregation, which is the clumping together of platelets in the blood that can lead to the formation of blood clots.
Pharmacokinetics:  
Absorption
avanafil is rapidly absorbed after oral administration, with a maximum plasma concentration reached in about 30 minutes.
Distribution
avanafil is highly bound to plasma proteins, primarily albumin, with a mean steady-state volume of distribution of about 105 L.
Metabolism
avanafil is mainly metabolized by cytochrome P450 3A4 (CYP3A4) to a biologically inactive compound.
Elimination and excretion
avanafil has a mean terminal half-life of about 5 hours, with about 87% of the dose being excreted in the feces and 13% in the urine.
Administration: 
Oral administration
avanafil is a medication used to treat erectile dysfunction (ED) in men. It is usually taken orally, with or without food, 30 minutes before sexual activity. The recommended starting dose is 100 mg, but it can be adjusted based on the individual’s response and tolerance to the medication. The maximum recommended dose is 200 mg per day.
Patient information leaflet
Generic Name: avanafil
Why do we use avanafil?
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