Important: This page is general information, not medical advice. It does not recommend or prescribe any treatment. Always consult your doctor or pharmacist before starting, stopping or changing any medicine.
Quick facts
- Drug class
- Phosphodiesterase 5 Inhibitor [EPC], Phosphodiesterase 5 Inhibitors [MoA]
- How it is given
- oral
- Type
- human prescription drug
- RxNorm ID
- 403957
We do not publish dosing. How much of this medicine to take, how often, and for how long depends on your age, weight, kidney and liver function, other conditions and other medicines. That is a decision for the person who prescribes or dispenses it. Follow the directions on your own pack and ask your pharmacist if anything is unclear.
What it is used to treat
Tadalafil is a phosphodiesterase 5 (PDE5) inhibitor indicated for the treatment of: erectile dysfunction (ED) ( 1.1 ) the signs and symptoms of benign prostatic hyperplasia (BPH) ( 1.2 ) ED and the signs and symptoms of BPH (ED/BPH) ( 1.3 ) If tadalafil is used with finasteride to initiate BPH treatment, such use is recommended for up to 26 weeks ( 1.4 ). 1.1 Erectile Dysfunction Tadalafil tablets are indicated for the treatment of erectile dysfunction (ED). 1.2 Benign Prostatic Hyperplasia Tadalafil tablets are indicated for the treatment of the signs and symptoms of benign prostatic hyperplasia (BPH). 1.3 Erectile Dysfunction and Benign Prostatic Hyperplasia Tadalafil tablets are indicated for the treatment of ED and the signs and symptoms of BPH (ED/BPH). 1.4 Limitation of Use If tadalafil tablets are used with finasteride to initiate BPH treatment, such use is recommended for up to 26 weeks because the incremental benefit of tadalafil tablets decreases from 4 weeks until 26 weeks, and the incremental benefit of tadalafil tablets beyond 26 weeks is unknown [see Clinical Studies ( 14.3 )] .
About this medicine
Tadalafil is a selective inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5 (PDE5). Tadalafil has the empirical formula C 22 H 19 N 3 O 4 representing a molecular weight of 389.41. The structural formula is: The chemical designation is pyrazino[1´,2´:1,6]pyrido[3,4-b]indole-1,4-dione, 6-(1,3-benzodioxol-5-yl)-2,3,6,7,12,12a-hexahydro-2-methyl-, (6R,12aR)-. It is a crystalline solid that is practically insoluble in water and very slightly soluble in ethanol. Tadalafil tablet, USP is available as yellow colored, oval-shaped, film coated tablets for oral administration. Each tablet contains 2.5, 5, 10, or 20 mg of tadalafil and the following inactive ingredients: lactose monohydrate, microcrystalline cellulose, croscarmellose sodium, copovidone, sodium lauryl sulfate, magnesium stearate, hypromellose, titanium dioxide, iron oxide yellow and triacetin. Chemical Structure
How it works
12.1 Mechanism of Action Penile erection during sexual stimulation is caused by increased penile blood flow resulting from the relaxation of penile arteries and corpus cavernosal smooth muscle. This response is mediated by the release of nitric oxide (NO) from nerve terminals and endothelial cells, which stimulates the synthesis of cGMP in smooth muscle cells. Cyclic GMP causes smooth muscle relaxation and increased blood flow into the corpus cavernosum. The inhibition of phosphodiesterase type 5 (PDE5) enhances erectile function by increasing the amount of cGMP. Tadalafil inhibits PDE5. Because sexual stimulation is required to initiate the local release of nitric oxide, the inhibition of PDE5 by tadalafil has no effect in the absence of sexual stimulation. The effect of PDE5 inhibition on cGMP concentration in the corpus cavernosum and pulmonary arteries is also observed in the smooth muscle of the prostate, the bladder and their vascular supply. The mechanism for reducing BPH symptoms has not been established. Studies in vitro have demonstrated that tadalafil is a selective inhibitor of PDE5. PDE5 is found in the smooth muscle of the corpus cavernosum, prostate, and bladder as well as in vascular and visceral smooth muscle, skeletal muscle, urethra, platelets, kidney, lung, cerebellum, heart, liver, testis, seminal vesicle, and pancreas. In vitro studies have shown that the effect of tadalafil is more potent on PDE5 than on other phosphodiesterases. These studies have shown that tadalafil is >10,000-fold more potent for PDE5 than for PDE1, PDE2, PDE4, and PDE7 enzymes, which are found in the heart, brain, blood vessels, liver, leukocytes, skeletal muscle, and other organs. Tadalafil is >10,000-fold more potent for PDE5 than for PDE3, an enzyme found in the heart and blood vessels. Additionally, tadalafil is 700-fold more potent for PDE5 than for PDE6, which is found in the retina and is responsible for phototransduction. Tadalafil is >9,000-fold more potent for PDE5 than for PDE8, PDE9, and PDE10. Tadalafil is 14-fold more potent for PDE5 than for PDE11A1 and 40-fold more potent for PDE5 than for PDE11A4, two of the four known forms of PDE11. […]
Who should not take it
Administration of tadalafil tablets to patients using any form of organic nitrate is contraindicated. Tadalafil was shown to potentiate the hypotensive effect of nitrates ( 4.1 ). History of known serious hypersensitivity reaction to tadalafil or ADCIRCA ® ( 4.2 ). Administration with guanylate cyclase (GC) stimulators, such as riociguat ( 4.3 ). 4.1 Nitrates Administration of tadalafil tablets to patients who are using any form of organic nitrate, either regularly and/or intermittently, is contraindicated. In clinical pharmacology studies, tadalafil was shown to potentiate the hypotensive effect of nitrates [see Clinical Pharmacology ( 12.2 )] . 4.2 Hypersensitivity Reactions Tadalafil tablets are contraindicated in patients with a known serious hypersensitivity to tadalafil (tadalafil tablets or ADCIRCA ® ). Hypersensitivity reactions have been reported, including Stevens-Johnson syndrome and exfoliative dermatitis [see Adverse Reactions ( 6.2 )] . 4.3 Concomitant Guanylate Cyclase (GC) Stimulators Do not use tadalafil tablets in patients who are using a GC stimulator, such as riociguat. PDE5 inhibitors, including tadalafil may potentiate the hypotensive effects of GC stimulators.
Warnings and cautions
Evaluation of erectile dysfunction and BPH should include an appropriate medical assessment to identify potential underlying causes, as well as treatment options. Before prescribing tadalafil tablets, it is important to note the following: Patients should not use tadalafil tablets if sex is inadvisable due to cardiovascular status ( 5.1 ). Use of tadalafil tablets with alpha-blockers, antihypertensives or substantial amounts of alcohol (≥5 units) may lead to hypotension ( 5.6 , 5.9 ). Tadalafil tablets are not recommended in combination with alpha-blockers for the treatment of BPH because efficacy of the combination has not been adequately studied and because of the risk of blood pressure lowering. Caution is advised when tadalafil tablets are used as a treatment for ED in men taking alpha-blockers. ( 2.7 , 5.6 , 7.1 , 12.2 ) Patients should seek emergency treatment if an erection lasts >4 hours. Use tadalafil tablets with caution in patients predisposed to priapism ( 5.3 ). Patients should stop tadalafil tablets and seek medical care if a sudden loss of vision occurs in one or both eyes, which could be a sign of non-arteritic anterior ischemic optic neuropathy (NAION). Tadalafil tablets should be used with caution, and only when the anticipated benefits outweigh the risks, in patients with a history of NAION. Patients with a "crowded" optic disc may also be at an increased risk of NAION ( 5.4 , 6.2 ). Patients should stop tadalafil tablets and seek prompt medical attention in the event of sudden decrease or loss of hearing ( 5.5 ). Prior to initiating treatment with tadalafil tablets for BPH, consideration should be given to other urological conditions that may cause similar symptoms ( 5.14 ). 5.1 Cardiovascular Physicians should consider the cardiovascular status of their patients, since there is a degree of cardiac risk associated with sexual activity. Therefore, treatments for erectile dysfunction, including tadalafil tablets, should not be used in men for whom sexual activity is inadvisable as a result of their underlying cardiovascular status. […]
Reported side effects
Most common adverse reactions (≥2%) include headache, dyspepsia, back pain, myalgia, nasal congestion, flushing, and pain in limb ( 6.1 ). To report SUSPECTED ADVERSE REACTIONS, contact VKT Pharma Pvt. Ltd at 1 844-387-1231 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. Tadalafil was administered to over 9000 men during clinical trials worldwide. In trials of tadalafil tablets for once daily use, a total of 1434, 905, and 115 were treated for at least 6 months, 1 year, and 2 years, respectively. For tadalafil tablets for use as needed, over 1300 and 1000 subjects were treated for at least 6 months and 1 year, respectively. Tadalafil Tablets for Use as Needed for ED In eight primary placebo-controlled clinical studies of 12 weeks duration, mean age was 59 years (range 22 to 88) and the discontinuation rate due to adverse events in patients treated with tadalafil 10 or 20 mg was 3.1%, compared to 1.4% in placebo treated patients. When taken as recommended in the placebo-controlled clinical trials, the following adverse reactions were reported ( see Table 1) for tadalafil tablets for use as needed: Table 1: Treatment-Emergent Adverse Reactions Reported by ≥2% of Patients Treated with Tadalafil Tablets (10 or 20 mg) and More Frequent on Drug than Placebo in the Eight Primary Placebo Controlled Clinical Studies (Including a Study in Patients with Diabetes) for Tadalafil Tablets for Use as Needed for ED a The term flushing includes: facial flushing and flushing Adverse Reaction Placebo (N=476) Tadalafil 5 mg (N=151) Tadalafil 10 mg (N=394) Tadalafil 20 mg (N=635) Headache 5% 11% 11% 15% Dyspepsia 1% 4% 8% 10% Back pain 3% 3% 5% 6% Myalgia 1% 1% 4% 3% Nasal congestion 1% 2% 3% 3% Flushing a 1% 2% 3% 3% Pain in limb 1% 1% 3% 3% Tadalafil Tablets for Once Daily Use for ED In three placebo-controlled clinical trials of 12 or 24 weeks duration, mean age was 58 years (range 21 to 82 […]
Interactions with other medicines
Tadalafil tablets can potentiate the hypotensive effects of nitrates, alpha-blockers, antihypertensives or alcohol ( 7.1 ). CYP3A4 inhibitors (e.g. ketoconazole, ritonavir) increase tadalafil exposure ( 2.7 , 5.10 , 7.2 ) requiring dose adjustment: Tadalafil tablets for use as needed: no more than 10 mg every 72 hours Tadalafil tablets for once daily use: dose not to exceed 2.5 mg CYP3A4 inducers (e.g. rifampin) decrease tadalafil exposure ( 7.2 ). 7.1 Potential for Pharmacodynamic Interactions with Tadalafil Tablets Nitrates — Administration of tadalafil tablets to patients who are using any form of organic nitrate, is contraindicated. In clinical pharmacology studies, tadalafil was shown to potentiate the hypotensive effect of nitrates. In a patient who has taken tadalafil tablets, where nitrate administration is deemed medically necessary in a life-threatening situation, at least 48 hours should elapse after the last dose of tadalafil tablets before nitrate administration is considered. In such circumstances, nitrates should still only be administered under close medical supervision with appropriate hemodynamic monitoring [see Dosage and Administration ( 2.7 ), Contraindications ( 4.1 ), and Clinical Pharmacology ( 12.2 )] . Alpha-Blockers — Caution is advised when PDE5 inhibitors are coadministered with alpha-blockers. PDE5 inhibitors, including tadalafil, and alpha-adrenergic blocking agents are both vasodilators with blood-pressure-lowering effects. When vasodilators are used in combination, an additive effect on blood pressure may be anticipated. Clinical pharmacology studies have been conducted with coadministration of tadalafil with doxazosin, tamsulosin or alfuzosin. [see Dosage and Administration ( 2.7 ), Warnings and Precautions ( 5.6 ), and Clinical Pharmacology ( 12.2 )] . Antihypertensives — PDE5 inhibitors, including tadalafil, are mild systemic vasodilators. Clinical pharmacology studies were conducted to assess the effect of tadalafil on the potentiation of the blood-pressure-lowering effects of selected antihypertensive medications (amlodipine, angiotensin II receptor blockers, bendrofluazide, enalapril, and metoprolol). […]
Use in specific groups
Hepatic Impairment ( 2.6 , 5.8 , 8.6 ): Mild or Moderate: Dosage adjustment may be needed. Severe: Use is not recommended. Renal Impairment ( 2.6 , 5.7 , 8.7 ): Patients with creatinine clearance 30 to 50 mL/min: Dosage adjustment may be needed. Patients with creatinine clearance less than 30 mL/min or on hemodialysis: For use as needed: Dose should not exceed 5 mg every 72 hours. Once daily use is not recommended. 8.1 Pregnancy Risk Summary Tadalafil tablets are not indicated for use in females. There are no data with the use of tadalafil tablets in pregnant women to inform any drug-associated risks for adverse developmental outcomes. In animal reproduction studies, no adverse developmental effects were observed with oral administration of tadalafil to pregnant rats or mice during organogenesis at exposures up to 11 times the maximum recommended human dose (MRHD) of 20 mg/day ( see Data). Data Animal Data Animal reproduction studies showed no evidence of teratogenicity, embryotoxicity, or fetotoxicity when tadalafil was given orally to pregnant rats or mice at exposures up to 11 times the maximum recommended human dose (MRHD) of 20 mg/day during organogenesis. In a prenatal/postnatal developmental study in rats, postnatal pup survival decreased following maternal exposure to tadalafil doses greater than 10 times the MRHD based on AUC. Signs of maternal toxicity occurred at doses greater than 16 times the MRHD based on AUC. Surviving offspring had normal development and reproductive performance. In another rat prenatal and postnatal development study at doses of 60, 200, and 1000 mg/kg, a reduction in postnatal survival of pups was observed. The no observed effect level (NOEL) for maternal toxicity was 200 mg/kg/day and for developmental toxicity was 30 mg/kg/day. This gives approximately 16 and 10 fold exposure multiples, respectively, of the human AUC for the MRHD of 20 mg. Tadalafil and/or its metabolites cross the placenta, resulting in fetal exposure in rats. 8.2 Lactation Risk Summary Tadalafil tablets are not indicated for use in females. […]
If too much is taken
Single doses up to 500 mg have been given to healthy subjects, and multiple daily doses up to 100 mg have been given to patients. Adverse events were similar to those seen at lower doses. In cases of overdose, standard supportive measures should be adopted as required. Hemodialysis contributes negligibly to tadalafil elimination.
Before you take anything new
Tell your pharmacist or doctor about every medicine you take — including ones bought without a prescription, herbal products and supplements. Interactions are one of the most common avoidable causes of harm from medicines, and a pharmacist can check your full list in a couple of minutes.
This page is built from the openFDA record of the U.S. Food and Drug Administration's approved labelling for this product, effective 16 October 2024. Label text has been shortened and reformatted for readability; safety wording has not been altered in meaning. FDA labelling describes products approved in the United States — brand names, strengths, formulations and approved uses may differ in your country. Always read the leaflet that comes with your own pack. PocketsInfo is not affiliated with, and is not endorsed by, the FDA. Retrieved 2026-07-30.