Tadalafil PRN

Generic for Cialis®

Tadalafil can be used both as a daily treatment or as needed. This treatment plan is focused on as needed tadalafil — how it works and how to effectively and safely use it to enhance erection strength and quality. You will also receive a physical document called a drug monograph or patient drug information in the package with your medication when it arrives from the pharmacy which contains full information about tadalafil — you should read all of the information that comes with your prescription shipment before taking your medication.

How tadalafil works

Tadalafil belongs to a class of medications called phosphodiesterase 5 inhibitors. These medications boost sexual performance by increasing blood flow to the penis. They work by blocking the enzyme that turns off an erection (phosphodiesterase-5).

In this treatment plan​

1.  Usage

How to get the most out of your treatment

2.  Side Effects

What to look out for when using your treatment

3.  Warnings

Important safety information



Tips for tadalafil use

How to get the most out of your ED treatment.​

1.  Timing is key

The effect of tadalafil on sexual performance depends directly on your blood level of tadalafil during sexual activity. Understanding how that blood level changes over time is critical so that you can optimize your performance. Tadalafil first starts to work after 30 minutes, provides maximal support for sexual function 2-6 hours after you take it, and boosts erection quality for up to 36 hours. (see below).

2.  Consider a practice run

Trying your first one or two sexual experiences on daily tadalafil in a less pressured, more relaxed environment (i.e. during masturbation) can help you to understand how the medication affects your body and whether or not any treatment adjustments might be helpful before primetime.

3.  Give tadalafil a few chances

It can take some time for your body to acclimate to tadalafil, so don’t rush to conclusions about whether or not it works. Things like alcohol consumption, fatigue, anxiety, and arousal can also affect sexual performance on any given day, even when you take medication to enhance sexual function.

4.  Get in the mood

Tadalafil works by enhancing and strengthening your body’s response to sexual stimulation and arousal. Some kind of mental or physical trigger is still required to kick off your body’s sexual response.

Tell your healthcare providers

Tell all your healthcare providers that you take tadalafil. If you need emergency medical care for a heart problem, it will be important for your healthcare provider to know when you last took tadalafil.


It is OK to drink alcohol when taking tadalafil, but not too much. Drinking more than 2-3 glasses of wine, beers, or shots of hard alcohol can increase your chances of headache, dizziness, fast heart rate, and low BP. Alcohol can also inhibit your erection.


Side Effects

Most common

The most common side effects with tadalafil are: headache, indigestion, back pain, muscle aches, flushing, and stuffy or runny nose. These side effects usually go away after a few hours. Men who get back pain and muscle aches usually get it 12 to 24 hours after taking tadalafil. Back pain and muscle aches usually go away within 2 days.

Rare but serious side effects

1.  An erection that won’t go away (priapism)

If you have an erection that lasts more than 4 hours, get medical help right away. If it is not treated right away, priapism can permanently damage your penis.

2.  Sudden vision loss

Sudden vision loss in one or both eyes can be a sign of a serious eye problem called non-arteritic anterior ischemic optic neuropathy (NAION). It is uncertain whether PDE5 inhibitors directly cause the vision loss. Stop taking tadalafil and call your healthcare provider right away if you have sudden vision loss in one or both eyes.

3.  Sudden hearing decrease or loss

Some people may also have ringing in their ears (tinnitus) or dizziness. If you have these symptoms, stop taking tadalafil and contact a provider right away.

4.  Other reported serious side effects

It is not known if tadalafil caused these problems, but other serious medical events that have been reported after tadalafil use include: heart attack, stroke, irregular heartbeats, seizures and death.

Where to find more side effects information

For more information, read the written drug information that comes with your medication, ask your healthcare provider, or ask your pharmacist.



Do not take tadalafil more than 1 time a day
Do not take more than your prescribed dose of tadalafil
Who should not take tadalafil
  • Anyone taking medicines called nitrates (such as nitroglycerin)

  • Anyone using street drugs called “poppers” such as amyl nitrate or butyl nitrate

  • Anyone taking medicines called guanylate cyclase stimulators such as riociguat (Adempas)

  • Anyone allergic to tadalafil or any of the ingredients in tadalafil

When to stop sexual activity

Stop sexual activity and seek medical help right away if you experience chest pain, dizziness, or nausea during sex after taking tadalafil. Sexual activity can put an extra strain on your heart, especially if your heart is already weak from a heart attack or heart disease.

Stop taking tadalafil until you connect with us or a healthcare provider if any of the following conditions or events develop during treatment:
  • Heart problems such as angina, heart failure, irregular heartbeats, or heart attack.

  • Pulmonary hypertension

  • Very low or very high blood pressure

  • Stroke

  • Liver problems

  • Kidney problems or require dialysis

  • Retinitis pigmentosa, a rare genetic (runs in families) eye disease

  • Vision loss

  • Stomach ulcers

  • Bleeding problems

  • Deformed penis shape or Peyronie’s disease

  • Erection lasting more than 4 hours

  • Blood problems such as sickle cell anemia, multiple myeloma, or leukemia

Stop taking tadalafil until you connect with us or a healthcare provider if you start any of the following medications during treatment:
  • Medicines called nitrates like nitroglycerin or isosorbide

  • Medicines called guanylate cyclase stimulators such as riociguat (Adempas)

  • Medicines called alpha blockers such as Hytrin (terazosin), Flomax (tamsulosin), Cardura (doxazosin), Minipress (prazosin), Uroxatral (alfuzosin), Jalyn (dutasteride and tamsulosin), or Rapaflo (silodosin). Alpha-blockers are sometimes prescribed for prostate problems or high blood pressure. In some patients, the use of tadalafil with alpha-blockers can lead to a drop in blood pressure or to fainting.

  • Medicines called HIV protease inhibitors, such as ritonavir (Norvir), indinavir sulfate (Crixivan), saquinavir (Fortovase or Invirase) or atazanavir sulfate (Reyataz)

  • Some types of oral antifungal medicines, such as ketoconazole (Nizoral), and itraconazole (Sporanox)

  • Some types of antibiotics, such as clarithromycin (Biaxin), telithromycin (Ketek), or erythromycin

  • Other medicines that treat high blood pressure

  • Other medicines or treatments for ED