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

5.4

mg

Orally 

every 8 hrs daily

Reduce dosage to 2.7 mg orally every 8 hours daily; if side effects appear,

then titrate gradually up to 5.4 mg orally every 8 hours daily

10 mg orally, one-hour prior sexual activity It may decrease to 5 mg or may increase to 20 mg
Based on effectiveness and tolerance, do not exceed more than 1 dose per day

Co-administration with CYP3A4 inhibitors
200 mg/day ketoconazole or 200 mg/day itraconazole
Dose of vardenafil should not exceed 5 mg/day
400 mg/day ketoconazole or 400 mg/day itraconazole
Dose of vardenafil should not exceed 2.5 mg/day
When combined with saquinavir, indinavir, clarithromycin, and atazanavir; do not exceed the dose of vardenafil more than 2.5 mg/72 hours
When combined with 500:

10 mg orally, one-hour prior sexual activity It may decrease to 5 mg or may increase to 20 mg
Based on effectiveness and tolerance, do not exceed more than 1 dose per day

Dose Adjustments

In the case of hepatic impairment- Child-Pugh class B, 5 mg orally 1 hour before intimacy in the form of film coated tablet
Not recommended in Child-Pugh class C

For <65 years
A film-coated tablet 10 mg orally an hour before intimacy
May be decreased to 5 mg or increased to 20 mg, based on the efficacy and tolerance
Do not exceed more than 1 dose/day
10 mg orally disintegrating tablet is placed on the tongue an hour before intimacy
Do not exceed more than 1 dose/day
The medication is not interchangeable with 10 mg of the film-coated tablet

For >65 years
5 mg initial dose
As AUC and Cmax are higher in older adults as compared to young men

10 mg orally initially as a single dose around half an hour before the anticipated sexual activity
The condition can be improved for 1.5 days after the single dose
Adjust the dose as required
May increase to 20 mg or decrease to 5 mg per dose
For daily dose- 2.5 mg initially once daily, disregard of sexual activity timing
Increase to 5 mg once daily based on the tolerability and efficacy

For erectile dysfunction, only Viagra is indicated
50 mg orally an hour before sexual intercourse
Time of administration may also range from 30 minutes to 4 hours before the sexual intercourse
Dose can be increased to 100 mg or decreased to 25 mg based on the efficacy and tolerance

2 capsules orally each day
3-4 capsules orally 90 minutes before sexual activity

Administer orally the ground leaves as decoction or powder

Take a dose of 40 mg orally four times in a day and it may be raised up to 80 mg four times daily if required

tadalafil is indicated for treatment of erectile dysfunction (ED)
Cialis/generic equivalent: No dosage adjustment is guaranteed singly based on age; however, a higher sensitivity towards medications in some geriatric people should be considered

Only Viagra is indicated for erectile dysfunction
For ≥65 years: Initially, 25 mg orally an hour before sexual intercourse
Time of administration may also range from 30 minutes to 4 hours before the sexual intercourse
Dose can be increased to 100 mg or decreased to 25 mg based on the efficacy and tolerance