Disclaimer: This article is for informational purposes only and does not constitute medical advice. It is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of a physician or other qualified health provider with any questions you may have regarding a medical condition.
Overview
Tadalafil is a prescription medicine. In Canada it is sold under the brand name Cialis, made by Eli Lilly. It belongs to a group of medicines called PDE5 inhibitors.
Health Canada has authorized Cialis for erectile dysfunction (ED) in men, for the signs and symptoms of benign prostatic hyperplasia (BPH, an enlarged prostate), and for ED and BPH together. It comes as 2.5 mg and 5 mg tablets for once-daily use and 10 mg and 20 mg tablets for use as needed.
Tadalafil needs a prescription. BC residents can speak with a BC-licensed doctor by phone through Avee Health to ask whether it is appropriate for them. The doctor decides based on your health history. A prescription is not guaranteed.
In Canada, Cialis (tadalafil) is authorized for:
- Erectile dysfunction in men, taken as needed or once a day
- Signs and symptoms of benign prostatic hyperplasia (BPH), taken once a day
- Erectile dysfunction and BPH together, taken once a day
Tadalafil is not authorized for women or for anyone under 18. It does not protect against sexually transmitted infections. Adcirca is a different tadalafil product, used for pulmonary arterial hypertension, with a different dose.
Tadalafil
Phosphodiesterase type 5 (PDE5) inhibitor
sexual health
Prescription required
Available
How Tadalafil Works
During sexual stimulation, the body makes a messenger in the penis that relaxes muscle and lets blood flow in. An enzyme called PDE5 breaks this messenger down. Tadalafil blocks PDE5, so an erection is easier to get and keep. It does not work without sexual stimulation.
Tadalafil can work within 30 minutes of taking a tablet, and the effect can last up to 36 hours. It can be taken with or without food.
Dosage Instructions of Tadalafil
Your doctor sets your dose. The usual doses in the Canadian product monograph are:
- ED, as needed: 20 mg before sexual activity, no more than once a day. Your doctor may adjust the dose depending on how well it works and how you tolerate it.
- ED, once daily: 5 mg at about the same time each day, whether or not you plan sexual activity. The dose may be lowered to 2.5 mg.
- BPH, or ED and BPH together: 5 mg once a day.
How to take it: swallow the tablet with or without food. Do not take more than one dose a day.
Kidney or liver problems: tell your doctor. As-needed doses are started lower and taken less often, and once-daily tadalafil is not recommended for people with severe kidney or liver problems.
Missed once-daily dose: ask your pharmacist what to do, and do not take two doses in one day.
Storage Instructions
Store at room temperature, between 15°C and 30°C.
Side Effects of Tadalafil
In clinical trials of as-needed use for ED, the most common side effects were (tadalafil compared with placebo):
- Headache: 11% compared with 4%
- Indigestion: 7% compared with 1%
- Back pain: 4% compared with 3%
- Muscle aches: 4% compared with 1%
- Stuffy nose: 4% compared with 2%
- Flushing: 4% compared with 1%
With once-daily use for ED, headache was reported by 4% (5% on placebo), indigestion by 4% (2%) and back pain by 3% (1%). With once-daily use for BPH, headache was reported by 3% (2%), indigestion by 3% (0.3%), back pain by 2% (1%) and high blood pressure by 2% (1%).
Get medical help right away if you have:
- An erection that lasts 4 hours or longer. Without prompt treatment this can damage the penis.
- Sudden loss or decrease of vision in one or both eyes
- Sudden decrease or loss of hearing, with or without ringing in the ears or dizziness
- Chest pain, fainting or severe dizziness. Call 911 and tell the emergency staff you take tadalafil, because nitrate medicines must not be given with it.
- Signs of a serious allergic reaction, such as a rash, swelling of the face or trouble breathing
Important Safety Information About Tadalafil
- Nitrates: do not take tadalafil if you use any form of nitrate medicine, such as nitroglycerin. The combination can cause a life-threatening drop in blood pressure. If a nitrate is needed in an emergency, at least 48 hours should pass after the last tadalafil dose before one is considered.
- Riociguat and other guanylate cyclase stimulators: do not combine them with tadalafil. They can cause a dangerous drop in blood pressure and fainting.
- Eye condition: do not take tadalafil if you have ever had non-arteritic anterior ischemic optic neuropathy (NAION), a cause of sudden vision loss in one eye. Some reports link PDE5 inhibitors to a higher risk of NAION.
- Heart and blood vessels: sex puts extra strain on the heart. Tadalafil was not studied in people who had a heart attack in the past 90 days, unstable angina, heart failure or a stroke in the past 6 months, uncontrolled heart rhythm problems, low blood pressure or uncontrolled high blood pressure. Tell the doctor about any heart condition.
- Allergy: do not take tadalafil if you are allergic to it or to any ingredient. The tablets contain lactose.
- Women, pregnancy and children: tadalafil is not for use in women, has not been studied in pregnant women, and is not for people under 18.
- Sperm: sperm concentration decreased in some men in studies. Whether this matters is not known.
- Sexually transmitted infections: tadalafil gives no protection against them.
Drug Interactions
Tell your doctor and pharmacist about everything you take, including non-prescription products. The main interactions are:
- Nitrates and riociguat: must not be combined with tadalafil.
- Alpha-blockers, such as doxazosin: blood pressure can drop further, so your doctor may adjust the doses. Tadalafil is not recommended together with an alpha-blocker for BPH.
- Ketoconazole and ritonavir: raise tadalafil levels, so a lower or less frequent dose is used.
- Rifampin: lowers tadalafil levels, so it may work less well.
- Grapefruit juice: may raise tadalafil levels slightly.
- Alcohol: both alcohol and tadalafil can lower blood pressure. Some people had dizziness on standing after a large amount of alcohol with tadalafil.
- Blood pressure medicines: no important extra drop in blood pressure was seen in studies. Still, tell the doctor which ones you take.
- Aspirin and warfarin: no important interaction was seen in studies.
Brands & DIN Number of Tadalafil
Brand Names
Cialis
Key Takeaways
- 1Tadalafil is the medicine in Cialis, authorized in Canada for erectile dysfunction, BPH symptoms, or both.
- 2For ED the usual dose is 20 mg as needed, no more than once a day, or 5 mg once daily. For BPH it is 5 mg once daily.
- 3It can work within 30 minutes and for up to 36 hours, and it can be taken with or without food.
- 4Never take it with nitrates or riociguat. The combination can drop blood pressure to a dangerous level.
- 5Headache, indigestion, back pain, muscle aches and flushing are the most common side effects.
- 6Get urgent care for an erection lasting 4 hours or more, sudden vision or hearing loss, or chest pain.
- 7Tadalafil needs a prescription. BC residents can ask a BC-licensed doctor by phone whether it is right for them.
Frequently Asked Questions
How much does tadalafil cost in Canada?
Does BC PharmaCare cover tadalafil?
How do I get tadalafil in BC?
How long does tadalafil take to work, and how long does it last?
What is the difference between taking tadalafil as needed and once daily?
Is there a generic tadalafil in Canada?
Can I drink alcohol with tadalafil?
Can I take tadalafil with heart or blood pressure medicine?
Avee Editorial
Avee Editorial Team