Vidalista (Tadalafil 2.5mg/5mg/10mg/20mg/40mg/60mg)

Medically reviewed by Dr. Sarah Mitchell, RPh, Clinical Pharmacist — Updated April 2026

Complete PDE5 Mechanism — How Tadalafil Works

Tadalafil is a selective, reversible inhibitor of phosphodiesterase type 5 (PDE5) — acting through the nitric oxide (NO)/cyclic GMP signalling pathway to facilitate penile erection:

• Sexual stimulation triggers nitric oxide (NO) release from parasympathetic nerve terminals and endothelial cells in the corpora cavernosa of the penis
• NO activates guanylate cyclase → cGMP production: NO activates guanylate cyclase in penile smooth muscle cells, producing cyclic guanosine monophosphate (cGMP)
• cGMP causes smooth muscle relaxation → arterial vasodilation → erection: cGMP activates protein kinase G (PKG), relaxing arterial and trabecular smooth muscle in the corpora cavernosa — allowing arterial blood to flow in under pressure, producing engorgement and rigidity
• PDE5 normally degrades cGMP, ending the erection. Tadalafil selectively inhibits PDE5, preventing cGMP breakdown — prolonging and amplifying smooth muscle relaxation and the erectile response

Why tadalafil's 36-hour window is unique: All PDE5 inhibitors share the same mechanism — their clinical differences lie entirely in pharmacokinetics. Tadalafil's plasma half-life of approximately 17.5 hours is more than three times longer than sildenafil's (3–5 hours) or vardenafil's (4–5 hours). This means effective plasma concentrations capable of PDE5 inhibition persist for up to 36 hours after a single dose — enabling sexual responsiveness at any point during this window without needing to time the tablet precisely around planned sexual activity. The 36-hour window does not mean a continuous erection — the penis remains flaccid between episodes of arousal; erectile response only occurs with sexual stimulation.

Why tadalafil has fewer visual side effects than sildenafil: Tadalafil has approximately 1,000-fold selectivity for PDE5 vs PDE6 (the phosphodiesterase in retinal photoreceptors). Sildenafil has only 10-fold selectivity. This greater PDE6 selectivity explains why the blue-green colour tinge and light sensitivity that frequently occur with sildenafil are substantially less common with tadalafil — an important practical advantage noticed by many Canadian men switching from sildenafil to tadalafil.

Vidalista Dosing Guide — All Six Strengths Explained

Vidalista's comprehensive range of 6 strengths corresponds to all clinical tadalafil dosing scenarios used in Canadian medical practice:

On-demand dosing (10mg, 20mg, 40mg, 60mg):

• Take 30 to 45 minutes before anticipated sexual activity
• Effect window: up to 36 hours — sexual stimulation is required for erection at any point during this window
• Maximum once per 24-hour period
• Can be taken with or without food — minimal food interaction (major advantage over sildenafil)
• Limit alcohol to 1 to 2 drinks — additive blood pressure lowering

Daily dosing (2.5mg, 5mg) — the "always-ready" approach:

• Take one tablet at the same time each day, regardless of whether sexual activity is planned
• Steady-state plasma concentrations are reached after approximately 5 days of daily dosing, maintaining continuous low-level PDE5 inhibition
• Allows erectile response at any time without planning — ideal for Canadian men who prefer complete spontaneity or who have frequent sexual activity
• Also effective for BPH urinary symptoms — 5mg once daily is approved by Health Canada for BPH
• The 2.5mg and 5mg daily approach produces fewer peak-concentration side effects (headache, flushing) compared to higher on-demand doses because plasma levels are lower and more stable

Vidalista vs Cialis Generic — What Is the Difference?

The most common question from Canadian patients: what exactly is different between Vidalista (generic tadalafil) and Cialis Generic?

Two Major Indications — ED and BPH

1. Erectile Dysfunction (ED)

Tadalafil is Health Canada-approved for ED in adult men — both on-demand (10mg/20mg) and daily low-dose (2.5mg/5mg). ED affects approximately 40% of Canadian men over 40 and is strongly associated with underlying vascular disease, diabetes (3 million+ Canadians), hypertension, metabolic syndrome, depression, and medication side effects. ED frequently precedes clinical cardiovascular events by 2 to 5 years — making evaluation by a Canadian physician essential for newly presenting ED, particularly in men under 60.

2. Benign Prostatic Hyperplasia (BPH) — Tadalafil's Second Canadian Indication

Tadalafil 5mg once daily is the only PDE5 inhibitor approved by Health Canada for benign prostatic hyperplasia — a non-cancerous enlargement of the prostate gland that causes urinary symptoms (weak urine stream, urgency, nocturia, incomplete bladder emptying, straining) in the majority of Canadian men over 50. This dual indication is clinically significant because ED and BPH coexist in approximately 50 to 70% of men over 50 — the same patient population, the same daily tablet, treating both conditions simultaneously.

The BPH mechanism: PDE5 is expressed in the smooth muscle of the prostate gland, urethra, and bladder neck. Tadalafil's PDE5 inhibition relaxes this smooth muscle — reducing the bladder outlet obstruction that causes BPH urinary symptoms — in addition to its penile vascular mechanism. This dual smooth muscle relaxation in both the penis and the lower urinary tract distinguishes tadalafil from all other ED medications for the management of men with concurrent ED and BPH.

Note: The BPH indication uses tadalafil 5mg once daily. The higher on-demand doses (10mg, 20mg, 40mg, 60mg) in Vidalista are not used for BPH treatment. Men with both ED and BPH should discuss with their Canadian physician which tadalafil dosing regimen (daily low-dose or on-demand) best addresses their specific symptoms.

Absolute Contraindications — When Vidalista Must NOT Be Taken

1. Nitrates in any form — ABSOLUTE CONTRAINDICATION, potentially fatal: This is the single most important safety warning for all PDE5 inhibitors including tadalafil. Combining tadalafil with any organic nitrate or nitrite produces synergistic, uncontrolled hypotension that can cause heart attack, stroke, and death. Absolutely contraindicated nitrates: glyceryl trinitrate/nitroglycerin (GTN) in all formulations — sublingual tablets (Nitrostat), spray (Nitrolingual), patches, IV; isosorbide mononitrate (Imdur); isosorbide dinitrate (Isordil); amyl nitrite and butyl nitrite (recreational "poppers"). Tadalafil's 36-hour half-life means the nitrate interaction risk persists for up to 48 hours after the last Vidalista dose — this is longer than with sildenafil. If you use poppers recreationally or take any nitrate medication — do not take Vidalista under any circumstances. In a cardiac emergency after tadalafil use, always inform emergency personnel when tadalafil was last taken.

2. Significant cardiovascular disease: Recent MI (within 90 days), recent stroke (within 6 months), unstable angina, uncontrolled hypertension, severe heart failure (NYHA Class III/IV), haemodynamic instability. Physician cardiovascular clearance is mandatory before starting tadalafil at any dose.

3. Severe hepatic impairment (Child-Pugh Class C): Tadalafil is not recommended.

4. Known hypersensitivity to tadalafil

5. Priapism risk conditions: Sickle cell anaemia, multiple myeloma, leukaemia, Peyronie's disease — discuss with urologist before use.

Side Effects — Complete Canadian Guide

Very common / common (≥1% of patients):

• Headache: Most common side effect — cerebral vasodilation. Occurs in approximately 11% of users at 20mg on-demand. Frequency increases with higher doses (40mg, 60mg). Usually mild to moderate; resolves within a few hours. Use acetaminophen (Tylenol) for relief. More frequent initially with daily dosing but typically diminishes after the first 1 to 2 weeks as the body adjusts
• Flushing: Facial redness and warmth — vasodilatory effect; common, self-limiting within 1 to 2 hours
• Nasal congestion / runny nose: Mucosal vasodilation; common and self-limiting
• Dyspepsia / heartburn: Smooth muscle relaxation of lower oesophageal sphincter; can take with food if problematic
• Dizziness: Blood pressure lowering — more pronounced with alcohol, alpha-blockers, antihypertensives, or at 40mg/60mg doses. Avoid sudden positional changes
• Back pain and muscle aches (myalgia) — unique to tadalafil: The most clinically distinctive tadalafil side effect not seen with other PDE5 inhibitors. Approximately 6 to 7% of tadalafil users experience diffuse back pain and myalgia — typically developing 12 to 24 hours after an on-demand dose, and resolving within 48 hours without specific treatment. The likely mechanism is tadalafil's inhibition of PDE11A — a phosphodiesterase expressed in skeletal muscle and reproductive tissue. The pain is not dangerous, not related to spinal pathology, and is not an indicator of serious adverse events. Analgesics (acetaminophen or ibuprofen) provide relief. Canadian patients should be counselled about this side effect in advance to avoid unnecessary alarm. Back pain with daily low-dose tadalafil (2.5mg/5mg) is less frequent than with higher on-demand doses

Serious — requiring immediate medical attention:

• Non-arteritic anterior ischaemic optic neuropathy (NAION) — sudden vision loss: Rare — sudden decrease or loss of vision due to optic nerve ischaemia. Risk factors: optic nerve crowding, prior NAION, age >50, diabetes, hypertension, smoking, hyperlipidaemia. Stop immediately and seek emergency ophthalmology care if any sudden vision change occurs. Vision loss from NAION may be permanent
• Sudden hearing loss: Rare; stop medication and seek emergency ENT evaluation immediately
• Priapism — erection >4 hours: Urological emergency requiring immediate emergency department attendance. Permanent erectile dysfunction results from untreated priapism within 4 to 6 hours
• Severe hypotension: Particularly with nitrate co-ingestion (absolutely contraindicated), alpha-blocker combinations, or in men with cardiovascular disease

Key Drug Interactions

• Nitrates (ALL forms) — ABSOLUTELY CONTRAINDICATED, risk persists for 48h post-dose: GTN/nitroglycerin, isosorbide mononitrate, isosorbide dinitrate, amyl nitrite/poppers. Fatal hypotension risk. No safe combination. Tadalafil's 36-hour half-life extends interaction risk longer than sildenafil
• Alpha-blockers (tamsulosin/Flomax, alfuzosin/Xatral, doxazosin, terazosin) — critical interaction in Canadian men with BPH+ED: The Vidalista 5mg daily dose is used by many Canadian men who also have BPH — a condition often treated with alpha-blockers. Both medications lower blood pressure; combination risks symptomatic orthostatic hypotension. Tamsulosin (Flomax) has the most favourable interaction profile with tadalafil among alpha-blockers. If both are used, start tadalafil at the lowest dose and after alpha-blocker dose is stable. Discuss with your Canadian physician or pharmacist
• Strong CYP3A4 inhibitors (ritonavir, ketoconazole, itraconazole, clarithromycin): Substantially increase tadalafil plasma levels. With ritonavir, tadalafil dose should not exceed 10mg per 72 hours. Avoid grapefruit juice on the day of higher-dose Vidalista
• CYP3A4 inducers (rifampicin, carbamazepine, phenytoin, St. John's Wort): Reduce tadalafil plasma levels significantly — reduced efficacy; may require dose adjustment under physician guidance
• Antihypertensive medications: Additive blood pressure lowering — very common scenario in Canadian men with hypertension and ED. Monitor for dizziness, particularly with calcium channel blockers and ACE inhibitors. Physician guidance essential
• Alcohol (≥5 standard drinks): Significant additive hypotension — avoid heavy drinking throughout the 36-hour tadalafil action window
• Other PDE5 inhibitors: Never combine; allow 48+ hours between tadalafil and other PDE5 inhibitor use

Delivery to All Canadian Provinces and Territories

drugs-canada.com ships Vidalista discreetly to all Canadian provinces and territories. Standard delivery: 4–9 business days.

Ontario (Toronto, Ottawa, Hamilton, London, Brampton, Mississauga, Kitchener-Waterloo) — Quebec (Montreal, Quebec City, Laval, Gatineau, Sherbrooke) — British Columbia (Vancouver, Surrey, Burnaby, Victoria, Kelowna, Abbotsford) — Alberta (Calgary, Edmonton, Red Deer, Lethbridge) — Manitoba (Winnipeg, Brandon) — Saskatchewan (Saskatoon, Regina) — Nova Scotia (Halifax, Sydney) — New Brunswick (Moncton, Saint John, Fredericton) — Newfoundland and Labrador (St. John's, Corner Brook) — Prince Edward Island (Charlottetown) — Northwest Territories (Yellowknife) — Yukon (Whitehorse) — Nunavut (Iqaluit).

All orders are dispatched in plain, unmarked packaging with no reference to the contents or sender. Every order includes a tracking number.

Frequently Asked Questions — Vidalista (Tadalafil) in Canada

What is the difference between Vidalista and Cialis Generic? Vidalista and Cialis Generic both contain tadalafil — the same active molecule — and produce identical pharmacological effects. The differences are manufacturer (Vidalista is made by Centurion Laboratories in India; Cialis is made by Eli Lilly), price (Vidalista is substantially more affordable), and the range of strengths available (Vidalista uniquely offers 2.5mg, 5mg, 10mg, 20mg, 40mg, and 60mg). The mechanism, onset, 36-hour duration, and side effect profile are identical across all tadalafil products.

What is the difference between Vidalista 5mg daily and Vidalista 20mg on-demand? These represent two different treatment philosophies. On-demand tadalafil (10mg or 20mg) is taken approximately 30 to 45 minutes before planned sexual activity — it produces a higher peak plasma concentration over a 36-hour window. Daily tadalafil (2.5mg or 5mg) is taken every day at the same time regardless of sexual activity — it maintains a steady low-level plasma concentration that enables erectile response at any spontaneous moment. Daily dosing is ideal for men who have sexual activity more than twice weekly, prefer complete spontaneity, or have concurrent BPH urinary symptoms (for which 5mg daily is Health Canada-approved). Canadian physicians often recommend trying on-demand dosing first before transitioning to daily dosing based on response and patient preference.

Why do I have back pain after taking tadalafil? Back pain and diffuse muscle aches (myalgia) are a well-recognised and unique side effect of tadalafil — occurring in approximately 6 to 7% of users. This does not occur with sildenafil or vardenafil. The pain typically develops 12 to 24 hours after an on-demand dose and resolves spontaneously within 48 hours. It is caused by tadalafil's inhibition of PDE11A in skeletal muscle — not related to spinal disc pathology and not dangerous. Acetaminophen or ibuprofen provides effective relief. If back pain after tadalafil is severe, persistent beyond 48 hours, or accompanied by other symptoms, consult your physician to rule out other causes.

Can I take Vidalista 5mg daily if I'm already on tamsulosin (Flomax) for my prostate? Tadalafil and tamsulosin can generally be combined — tamsulosin has the most favourable blood pressure interaction profile among alpha-blockers when used with tadalafil. However, blood pressure can still decrease when both are combined, so initiating tadalafil at the lowest dose (2.5mg daily) with a stabilised tamsulosin regimen is the recommended approach. Many Canadian urologists and family physicians regularly manage patients on both medications for concurrent ED and BPH. The tadalafil 5mg once-daily dose is actually Health Canada-approved specifically for BPH and for ED+BPH — making it an elegant solution for Canadian men with both conditions.

How long does delivery to Canada take? Standard delivery to all Canadian provinces and territories takes 4 to 9 business days. All orders arrive in plain, unmarked packaging with no reference to the contents or sender. Every order includes a tracking number.

All information on this page is for general informational purposes only and does not constitute medical advice. Vidalista (Tadalafil) is a prescription medicine in Canada — a valid prescription from a licensed Canadian healthcare provider is required. Vidalista 40mg and 60mg contain doses that exceed Health Canada's standard approved maximum on-demand tadalafil dose of 20mg — physician assessment is mandatory before use. Tadalafil is absolutely contraindicated with nitrates in any form, including recreational nitrites ("poppers"). If you experience sudden vision loss, sudden hearing loss, chest pain, or priapism (erection lasting more than 4 hours), seek emergency medical care immediately. Always consult a qualified Canadian physician before starting any medication for erectile dysfunction or BPH.