Tadalafil instructions for use, how to take?

This page is an instruction manual for the use of tadalafil and all generics based on it presented in the GENERICS catalog: Tadarise, Vidalista, Tadalista, Apcalis SX, Tadalis SX, Tadagra, and others. Their active ingredient is the same — tadalafil. The mechanism of action, dosages, contraindications, and interactions are identical for all these drugs.

What is Tadalafil

Tadalafil is an active substance from the group of PDE-5 (phosphodiesterase type 5) inhibitors. It was first approved by the FDA on November 21, 2003, under the brand name Cialis® (Cialis®, manufactured by Eli Lilly and Company).[1] In the same year, the drug received approval in Europe and Australia, quickly earning a reputation as the "weekend pill" due to its record-breaking duration of action among PDE-5 inhibitors — up to 36 hours.

Over the past 20+ years, tadalafil has become one of the most studied drugs in urology and sexual medicine, receiving approval for several indications at once: erectile dysfunction (ED), benign prostatic hyperplasia (BPH/prostate adenoma), a combination of both conditions — and even pulmonary arterial hypertension (at a dosage of 40 mg under a different brand name).

Today, there are hundreds of generics based on tadalafil. A generic contains the same molecule in the same dosage, is manufactured according to GMP standards, and costs several times less than the original. The only difference is in the brand name, manufacturer, and auxiliary components of the packaging, which have practically no effect on the drug's effectiveness.

How Tadalafil Works

Erection is a vascular process. Upon sexual arousal, nerve endings release nitric oxide (NO), which triggers the synthesis of cyclic guanosine monophosphate (cGMP). cGMP relaxes the smooth muscles of the vessels of the corpora cavernosa, causing an influx of blood and forming an erection.

The PDE-5 enzyme constantly breaks down cGMP, limiting the erection. In erectile dysfunction, PDE-5 activity is excessive — cGMP does not have time to accumulate, and the erection does not reach the desired hardness or quickly weakens. Tadalafil blocks PDE-5, preventing it from breaking down cGMP prematurely.

Scheme: upon sexual arousal, nitric oxide is produced → triggers cGMP synthesis → relaxes blood vessels → erection. The PDE-5 enzyme breaks down cGMP and dampens the process. Tadalafil blocks PDE-5, preventing cGMP from being destroyed prematurely.

Crucially important: tadalafil does not cause an erection automatically — sexual arousal is necessary for it to work. Without it, the drug does not work.

How does tadalafil differ from other PDE-5 inhibitors at the molecular level? The main thing is its high selectivity for PDE-5 with minimal effect on related enzymes PDE-6 (retina of the eye) and PDE-11 (muscle tissue). This is why tadalafil has practically no color perception disorders characteristic of sildenafil — but its specific side effect is muscle pain (myalgia) and back pain associated with PDE-11 inhibition.[2]

The half-life of tadalafil is about 17.5 hours, which is approximately 4 times longer than that of sildenafil and vardenafil (~4–5 hours). This is what ensures such a long-lasting action. 36 hours after administration, about 25% of the absorbed dose remains in the body — a clinically significant concentration is still present, although the effect is already weakening.[3]

Dosages and Regimens of Administration

Tadalafil is the only PDE-5 inhibitor for which there are two fundamentally different regimens of use: "on demand" and daily administration. This expands the choices for a specific lifestyle.

"On Demand" Regimen

The standard approach is to take a pill 30–60 minutes before planned sexual activity, when needed.

• 10 mg — the recommended starting dose "on demand". The official instructions for Cialis advise starting with 10 mg. It is suitable for the first acquaintance with the drug and for most men with mild to moderate ED. If the result is sufficient, there is no need to increase the dose.
• 20 mg — the standard therapeutic dose "on demand". It is prescribed for an insufficient response to 10 mg. It is used by most men with moderate to severe ED. The maximum officially recommended single dose when taken "on demand".
• 40 mg and 80 mg — dosages that are found only in generics and go beyond the officially studied range. The logic of their existence is the ability to divide the tablet and get several standard doses at a more favorable price. You should not exceed the 20 mg dose on your own without a doctor's recommendation: the risk of side effects increases, and there is no documented increase in efficacy beyond 20 mg for ED.

Daily Administration Regimen (for a Continuous Effect)

Tadalafil in low doses can be taken every day — then it maintains a constant concentration in the blood, and potency is in a "working state" constantly, without being tied to a pill before a specific occasion.

• 2.5 mg — starting dose for daily use. If necessary, an increase to 5 mg is possible.
• 5 mg — standard dose for daily use. This is the most studied regimen for continuous ED therapy. In addition to potency, tadalafil 5 mg is the only PDE-5 inhibitor officially approved for the treatment of symptoms of benign prostatic hyperplasia (BPH) — it helps ease urination in men with adenoma. This is especially relevant for men 50+, in whom both problems often coexist.[4]

Maximum frequency of administration: 1 time per day, regardless of dosage and regimen.

How to Take

Time of Administration

With the "on demand" regimen, the pill is taken 30–60 minutes before planned sexual activity. Do not chew or crush, swallow with water. According to clinical studies, the effect in some men occurs as early as 16–30 minutes after taking on an empty stomach, although the median time to peak action is about 2 hours.[3]

With the daily regimen, the pill is taken at approximately the same time of day, regardless of planned sexual activity. A stable concentration in the blood is achieved after about 5 days of regular administration.

What to drink with: clean non-carbonated water (~200 ml). Grapefruit juice is contraindicated: it inhibits the CYP3A4 enzyme in the gut and increases the concentration of tadalafil in the blood.

Food Effect

One of the key advantages of tadalafil over sildenafil is that it is practically independent of food. A fatty meal, a heavy dinner, a light snack — none of this affects the rate and completeness of absorption of the drug. This has been confirmed by pharmacokinetic studies: the rate and degree of absorption when taken with food and on an empty stomach do not differ statistically.[3] In practice, this means that tadalafil can be taken right at dinner, and the effect will not suffer.

Alcohol

Moderate doses of alcohol are not an absolute contraindication. Tadalafil is less likely than sildenafil to cause a pronounced decrease in blood pressure — but both substances are vasodilators, and their combined effect with alcohol can increase dizziness, tachycardia, and hypotension. Recommendation: no more than 1–2 glasses of wine a few hours before taking. With a daily regimen — similarly, alcohol abuse is contraindicated in principle. The FDA Label indicates that consuming a significant amount of alcohol can increase orthostatic hypotension.

Efficacy

The clinical program of tadalafil is one of the largest in the history of ED drugs. It included dozens of randomized controlled trials involving thousands of men of different ages and with various concomitant diseases.

Overall Efficacy in ED

In placebo-controlled trials when taken "on demand", tadalafil provided successful intercourse significantly more often than placebo. In a pooled analysis of data, tadalafil significantly improved all key IIEF score parameters compared to baseline and placebo — regardless of age, presence of comorbid conditions, and severity of ED.[5]

In Diabetes Mellitus

ED occurs in 50–75% of men with diabetes and is traditionally considered a more difficult form to treat. In the SURE study (14 European countries, men with diabetes and ED), with both regimens of tadalafil administration, more than 58% of intercourse attempts were successful according to the SEP3 indicator, and efficacy was maintained up to 36 hours after administration. The drug was well tolerated, the most common adverse events being dyspepsia and headache.[6]

In Benign Prostatic Hyperplasia (Adenoma)

Tadalafil 5 mg is the only PDE-5 inhibitor approved by the FDA for the treatment of BPH symptoms. A meta-analysis of 8 studies showed: compared with placebo, tadalafil significantly reduced the total symptom score on the IPSS scale (by an average of 2.2 points) and simultaneously improved erectile function (IIEF +4.66 points). This makes tadalafil 5 mg the drug of choice for men in whom ED and lower urinary tract symptoms are combined — that is, for a significant proportion of men 50+.[7]

In Older Men (65+)

In the open-label clinical trial MOMENTUS (men 65+, mean age 65 years, most with several comorbid conditions, including 72% with diabetes and 67% with cardiovascular pathology), tadalafil 20 mg significantly improved the IIEF erectile function score by an average of 7.6 points. Among men with severe ED, 22% achieved a normal level of erection. The drug was well tolerated.[8]

It is important to understand: tadalafil eliminates the symptom (erectile dysfunction), but not the cause of ED. If you do not deal with the root cause (vascular disorders, hormonal deficiency, diabetes), the problem will progress. The drug works particularly poorly in case of complete damage to nerve bundles — for example, after non-nerve-sparing prostate surgery or in severe diabetic neuropathy.

Side Effects

Tadalafil is considered one of the most well-tolerated PDE-5 inhibitors — its incidence of side effects is slightly lower than that of sildenafil. This is primarily due to the high selectivity of the molecule for PDE-5 and minimal effect on PDE-6 (responsible for vision).

Common (in 5–15% of patients)

Headache, dyspepsia (heartburn, abdominal discomfort), nasal congestion, facial flushing. All of these reactions are dose-dependent and resolve on their own within a few hours. They are typical for the entire class of PDE-5 inhibitors and are caused by vasodilation.

Side Effect Specific to Tadalafil

Back pain and myalgia (pain in the muscles of the limbs) are a characteristic feature of tadalafil, which is practically absent in sildenafil and vardenafil. It is associated with partial inhibition of PDE-11, which is present in muscle tissue. According to clinical trials, back pain and myalgia occur 12–24 hours after administration and, as a rule, resolve on their own within 48 hours. Usually mild or moderate.[2]

Uncommon (0.1–1%)

Dizziness, diarrhea, mild visual impairment (much less common than with sildenafil — due to low affinity for PDE-6).

Rare but Serious (<0.1%)

• Priapism — a painful erection lasting more than 4 hours. Requires immediate medical attention. With delay, irreversible damage to the tissues of the penis is possible.
• NAION (non-arteritic anterior ischemic optic neuropathy) — sudden vision impairment. The link with PDE-5 inhibitors is debatable; the risk is higher in patients with pre-existing risk factors (diabetes, hypertension, small optic disc).
• Sudden decrease in hearing — isolated post-marketing cases, a causal relationship has not been established.

Compared to sildenafil: tadalafil is much less likely to cause color perception impairment ("blue haze") — since it inhibits retinal PDE-6 to a much lesser extent. However, tadalafil has its own specific side effect — back pain and myalgia, which are practically absent with sildenafil.

Contraindications

Absolute (cannot be taken under any circumstances)

• Nitrates in any form — nitroglycerin, isosorbide dinitrate/mononitrate, nitro spray, isoket spray. Joint administration with tadalafil causes a sharp and potentially life-threatening drop in blood pressure. This is the most critical interaction.
• Riociguat (Adempas®) — a drug for pulmonary hypertension. Joint administration is contraindicated.
• Severe cardiovascular diseases in which sexual activity is contraindicated in principle: unstable angina, myocardial infarction less than 3 months ago, stroke less than 6 months ago, severe heart failure (NYHA class III–IV), uncontrolled arrhythmias.
• Severe hepatic impairment (Child-Pugh C) — use has not been studied, cannot be used.
• Loss of vision in one eye due to NAION in history — risk of a repeat episode in the other eye.
• Hypersensitivity to tadalafil or auxiliary components.
• Age under 18 years.

Relative (require caution and consultation with a doctor)

• Controlled hypertension and stable coronary artery disease — use is possible, but only after assessing cardiac risk.
• Anatomical deformities of the penis (Peyronie's disease, cavernous fibrosis) — increased risk of priapism.
• Diseases predisposing to priapism: sickle cell anemia, leukemia, multiple myeloma.
• Retinitis pigmentosa.
• Moderate renal impairment (creatinine clearance 31–50 ml/min) — starting dose 5 mg, maximum 10 mg no more than once every 48 hours.
• Moderate hepatic impairment (Child-Pugh A–B) — the dose should not exceed 10 mg per day.

Drug Interactions

Critically Dangerous — Absolute Contraindication

Nitrates and nitric oxide donors. Joint administration can cause critical hypotension. If you take nitrates regularly, tadalafil is completely contraindicated. An important feature of tadalafil compared to sildenafil: due to the long half-life, the interval to safe nitrate administration after tadalafil is at least 48 hours (and not 24, as with sildenafil). And vice versa: after taking nitrate, you need to wait at least 24–48 hours before taking tadalafil.[9]

Riociguat — joint administration is absolutely contraindicated.

Require Dose Adjustment

Strong CYP3A4 inhibitors (ketoconazole, itraconazole, ritonavir, and other HIV protease inhibitors, clarithromycin) — significantly increase the concentration of tadalafil in the blood. With joint administration, the maximum dose of tadalafil is 10 mg no more than once every 72 hours.

CYP3A4 inducers (rifampicin, carbamazepine, phenytoin, St. John's wort) — reduce the concentration of tadalafil, the effect of the drug may decrease.

Alpha-blockers (doxazosin, tamsulosin — used for prostate adenoma) — additive hypotensive effect. The FDA Label recommends that when used jointly with doxazosin, make sure the patient is stable on one of them before adding the second. Tamsulosin (highly selective) interacts more mildly.

Moderate Interactions

Grapefruit juice inhibits CYP3A4 in the gut — it is best to avoid joint consumption. Antacids based on magnesium/aluminum hydroxide may slightly reduce the rate of absorption, but not the overall exposure.

Have Practically No Effect on Pharmacokinetics

Warfarin, digoxin, theophylline, antihypertensive drugs (calcium channel blockers, ACE inhibitors, diuretics) — no clinically significant interaction was found.

If you are taking several medications, be sure to check interactions with your doctor or pharmacist. This especially applies to drugs for the heart, blood pressure, and fungal infections.

Special Patient Groups

Older Men (65+)

In older men, the clearance of tadalafil is reduced by about 25%, which leads to a higher concentration of the drug in the blood at the same dose. Dose adjustment is not necessary, but caution should be exercised, especially in the presence of comorbid conditions and polypragmasy. It is recommended to start with 10 mg.

Diabetes Mellitus

Tadalafil is effective in diabetic ED, although the response in this group is slightly lower than in men without diabetes — due to neuropathy and vascular disorders. The standard starting dose is 10 mg, with an insufficient response — 20 mg. Tadalafil 5 mg with a daily regimen can be especially convenient for men with diabetes, for whom predictability is important.

Prostate Adenoma (BPH)

Tadalafil 5 mg once a day is the only PDE-5 inhibitor approved by the FDA for the treatment of BPH symptoms. The mechanism of action on the prostate and urinary tract is associated with smooth muscle relaxation through the same NO/cGMP pathway. If a man simultaneously has ED and lower urinary tract symptoms (difficulty urinating, incomplete emptying of the bladder), tadalafil 5 mg solves both problems with one drug.

Kidney Diseases

Mild renal impairment (CrCl >50 ml/min) — no correction is needed. Moderate (CrCl 31–50 ml/min) — start with 5 mg, maximum 10 mg no more than once every 48 hours. Severe (CrCl <30 ml/min, hemodialysis) — maximum 5 mg once.

Liver Diseases

Mild and moderate impairment (Child-Pugh A–B) — dose no more than 10 mg per day. Data on higher doses in hepatic impairment are absent. Severe impairment (Child-Pugh C) — contraindicated.

Cardiovascular Diseases

Controlled hypertension and stable CAD are not absolute contraindications. Clinical trials included men with carefully selected cardiovascular pathology — while tadalafil had no clinically significant effect on heart rate and blood pressure. The decision is made jointly with a cardiologist.

What to Do If...

...the drug did not work

The most common reasons for the lack of effect:

• Too short waiting time — less than 30 minutes after administration, although the median Tmax is about 2 hours.
• Insufficient sexual arousal: tadalafil enhances the response to stimulation, but does not replace it.
• Anxiety during the first use — the psychological factor really reduces effectiveness.
• Consuming a large amount of alcohol.

The manufacturer recommends evaluating effectiveness after at least 4–8 attempts in different conditions. If 10 mg does not work, try 20 mg. If 20 mg is also ineffective after several doses, consult a doctor to find out the root cause of ED.

...side effects occurred

• Headache, facial flushing, nasal congestion, heartburn — as a rule, resolve on their own after a few hours. Next time you take it, try reducing the dose.
• Back and muscle pain — a specificity of tadalafil. Usually appears after 12–24 hours and resolves on its own within 48 hours. If the pain is severe or does not go away, consult a doctor.
• Sudden dizziness or drop in blood pressure — lie down, raise your legs, drink water. If it does not improve or you have consumed alcohol, call an ambulance.
• Chest pain — call an ambulance immediately. It is categorically forbidden to take nitroglycerin: taking it together with tadalafil is life-threatening. Inform the medical staff that you took tadalafil and when — the safety interval before nitrate is at least 48 hours.

...the erection does not go away (priapism)

If the erection is painful and does not subside 2–3 hours after the end of intercourse, this is an emergency situation.

Immediately contact the nearest emergency room or call an ambulance. Treatment in the first 4–6 hours allows preserving the function of the penis. Delay threatens irreversible damage to the corpora cavernosa and permanent impotence. This is a rare complication (<0.1%), but it is important to know about its symptoms in advance.

...an excessive dose was taken (overdose)

There is no specific antidote. Symptoms are an increase in typical side effects: pronounced headache, severe flushing, sharp drop in blood pressure, visual impairment.

Stop taking, lie down, with a pronounced decrease in blood pressure or loss of consciousness — call an ambulance. Report the dose and time of administration. Nitrates must not be taken under any circumstances. Dialysis is ineffective due to the high binding of tadalafil to plasma proteins.

...you missed a dose (daily regimen)

With daily administration of 2.5 or 5 mg: take the missed dose as soon as you remember, if there is still a lot of time before the next dose. If the time has almost come, just take the next dose on schedule, without doubling it. With the "on demand" regimen, the concept of a "missed dose" is not applicable.

Storage Conditions

Store at a temperature not exceeding 30°C, in a dry place protected from direct sunlight. Keep out of reach of children. The expiration date is indicated on the package, usually 2–3 years. Do not use after the expiration date.

Tadalafil-Based Drugs in Our Catalog

All listed drugs contain tadalafil as an active ingredient. This instruction manual applies to all of them. The differences are in the manufacturer, auxiliary components, and packaging design; the mechanism of action, indications, contraindications, and interactions are identical.

By Dosage

• Tadalafil 2.5 mg — Tadarise 2.5, Vidalista 2.5, and others (daily regimen, prostate adenoma)
• Tadalafil 5 mg — Tadarise 5, Vidalista 5, Tadalista 5, and others (daily regimen, adenoma)
• Tadalafil 10 mg — Tadarise 10, Vidalista 10, Tadalista 10, and others (starting dose "on demand")
• Tadalafil 20 mg — Tadarise 20, Vidalista 20, Tadalista 20, Apcalis SX 20, Tadalis SX 20, Tadagra 20, and others (standard therapeutic dose)
• Tadalafil 40 mg — Tadarise 40, Vidalista 40, Tadalista 40, and others
• Tadalafil 60 mg — Tadarise 60, Vidalista 60, Tadalista 60, and others
• Tadalafil 80 mg — Tadarise 80, Vidalista 80, and others

Alternative Release Forms

• Tadalafil Soft and Oral Jelly — Tadarise Pro, Tadasoft 20, Vidalista CT, Apcalis Oral Jelly, Chocolis 20, and others

Combination Drugs (Tadalafil + Dapoxetine)

If, in addition to ED, rapid ejaculation is also relevant, tadalafil as a monotherapy does not solve this problem. In the GENERICS catalog, 2-in-1 pills for erection and delay are available:

• Super Tadarise — tadalafil 20 mg + dapoxetine 60 mg
• Extra Super Tadarise — tadalafil 40 mg + dapoxetine 60 mg
• Super Vidalista — tadalafil 20 mg + dapoxetine 60 mg
• Vidalista D — tadalafil 20 mg + dapoxetine 60 mg
• Tadapox — tadalafil 20 mg + dapoxetine 60 mg

If you are interested in a specific brand, see the page of that drug — the features of the specific dosage are described there.

The information on this page is for informational purposes only and does not replace consultation with a doctor. Before using any tadalafil-based drug for the first time, consult a urologist or general practitioner — especially in the presence of cardiovascular diseases, taking other medications, or chronic diseases.

Frequently Asked Questions

What is the difference between "on demand" and daily administration?

With the "on demand" regimen (10 or 20 mg), the pill is taken 30–60 minutes before intimacy — when needed. Convenient for men with an irregular sex life.

With the daily regimen (2.5 or 5 mg), the pill is taken every day at the same time, regardless of plans for intimacy. A constant concentration of the drug is created — and potency is in a "working state" continuously. Convenient for men with an active but spontaneous sex life, as well as in the treatment of prostate adenoma symptoms. The effectiveness of both regimens is comparable.

Can Tadalafil be taken with food and alcohol?

With food — yes, without restrictions. Fatty food does not affect the absorption of tadalafil. This is one of its main advantages over sildenafil, where a heavy fatty dinner can significantly delay the action.

With alcohol — moderate doses are not contraindicated, but you should not abuse it: both substances lower blood pressure, and in combination this can cause dizziness. 1–2 glasses of wine is acceptable. Large doses of alcohol, among other things, worsen erection on their own.

How does Tadalafil differ from generic Cialis?

In no fundamental way. Cialis is the brand name of tadalafil from Eli Lilly. Generics (Tadarise, Vidalista, Tadalista, and others) contain the same molecule in the same dosage, manufactured according to GMP standards. The difference is in the manufacturer, auxiliary components, and price. Generics cost 3–10 times less than the original.

Does Tadalafil help with prostate adenoma?

Yes. Tadalafil 5 mg in a daily regimen is the only PDE-5 inhibitor officially approved by the FDA for the treatment of symptoms of benign prostatic hyperplasia (BPH). It relaxes the smooth muscles of the prostate and bladder neck, easing urination. This is especially convenient for men in whom ED and adenoma symptoms coexist — one drug solves both problems.

Does Tadalafil cause addiction?

No. Tadalafil is not a drug or a hormone. Physical dependence does not form. In a study lasting 6 months, no signs of tolerance (addiction) to the drug were identified: efficacy did not decrease over time. After stopping the drug, the function of the penis returns to its baseline level.

What if I took Tadalafil, and then needed Nitroglycerin?

This is a critical question. Joint administration of tadalafil with nitrates (nitroglycerin, nitro spray) can cause a dangerous drop in blood pressure. Due to the long half-life of tadalafil, the safe interval before taking nitrate is at least 48 hours (as opposed to 24 hours for sildenafil).

If you have chest pain after taking tadalafil, call an ambulance immediately and inform the medical staff that you took tadalafil. Do not take nitroglycerin on your own. Doctors in an emergency situation know about this interaction and use other drugs to relieve heart pain.

Sources

• [1] FDA. Drug Approval Package: Cialis (tadalafil) NDA #021368. Approved: November 21, 2003. FDA.gov
• [2] Smith-Harrison L.I. et al. The devil is in the details: an analysis of the subtleties between phosphodiesterase inhibitors for erectile dysfunction. Translational Andrology and Urology, 2016; 5(2): 181–189. PMC: 4837309
• [3] Forgue S.T. et al. Tadalafil pharmacokinetics in healthy subjects. British Journal of Clinical Pharmacology, 2006; 61(3): 280–288. PMC: 1885023
• [4] Roehrborn C.G. et al. Tadalafil 5 mg once daily improves lower urinary tract symptoms and erectile dysfunction: results from TADLUT, a randomized, double-blind, placebo-controlled trial. European Urology, 2011; 60(5): 1105–1113. PubMed: 21981682
• [5] Donatucci C.F. et al. Tadalafil once daily in men with erectile dysfunction: an integrated analysis of data obtained from 1913 patients from six randomized, double-blind, placebo-controlled clinical studies. The Journal of Sexual Medicine, 2014; 11(1): 191–200. PubMed: 24119319
• [6] Buvat J. et al. Efficacy and safety of tadalafil in men with erectile dysfunction with a high prevalence of comorbid conditions: results from SURE study. The Journal of Sexual Medicine, 2006; 3(3): 512–522. PubMed: 16681477
• [7] Gacci M. et al. Efficacy and safety of tadalafil monotherapy for lower urinary tract symptoms secondary to benign prostatic hyperplasia: a meta-analysis. Urologia Internationalis, 2013; 91(3): 312–319. PubMed: 23816815
• [8] Sharlip I.D. et al. Efficacy and safety of tadalafil in men with erectile dysfunction with a high prevalence of comorbid conditions. Results from MOMENTUS. The Journal of Sexual Medicine, 2007; 4(4): 1006–1015. PubMed: 17233782
• [9] FDA Label — Cialis® (tadalafil) Tablets. Full Prescribing Information. FDA.gov (PDF)

The sources describe the tadalafil molecule and apply to all drugs based on it — both the original Cialis® and generics.