In , Pfizer scientists discovered that sildenafil, which also inhibits the PDE5 enzyme, caused penile erection in males participating in a clinical study of a heart medicine. Therefore the use of such treatments in combination with Cialis is not recommended. Tadalafil can be synthesized starting from D – tryptophan methyl ester and piperonal via a Pictet—Spengler reaction. The FDA has also approved tadalafil for treatment of both benign prostatic hypertrophy and erectile dysfunction where the two conditions co-exist. Cialis should not be used by patients taking nitrates such as nitroglycerin tablets or patches because the combination of these with Cialis could significantly lower blood pressure and lead to fainting or even death in some men. CIALIS can cause your blood pressure to drop suddenly to an unsafe level if it is taken with any nitrate medication.The recommended starting dose for Cialis intended for once daily use is mg, take at the same time each day, without regard to timing of sexual activity. This may be increased to 5mg/day based on need and tolerability. May be taken with or without food. Cialis is available as a generic, under the name tadalafil. 3. The drug comes in low-dose versions that can be taken daily. This means you can have sex at any time, rather than needing to take a pill from time to time as needed like other ED brands. The starting dose for daily-use Cialis is milligrams (mg). If that doesn’t work, you can increase your daily dose up to 5 mg. Daily Cialis / Tadalafil For those of you that take daily cialis / tadalafil, have you found any benefit to modifying the time you take it every day? I’ve been taking mine with my daily .