CIALIS
Clinical safety rating: caution
Comprehensive clinical and safety monograph for CIALIS (CIALIS).
Phosphodiesterase-5 (PDE5) inhibitor; increases cGMP levels, causing smooth muscle relaxation and vasodilation in the corpus cavernosum, enhancing erectile function.
| Metabolism | Primarily hepatic via CYP3A4; minor pathways include CYP2C9 and glucuronidation. |
| Excretion | Following oral administration, tadalafil is predominantly eliminated by hepatic metabolism. The metabolites are excreted mainly in feces (approximately 61% of the dose) and to a lesser extent in urine (approximately 36% of the dose). No unchanged parent drug is detected in urine. |
| Half-life | The terminal elimination half-life of tadalafil is approximately 17.5 hours in healthy subjects, which supports once-daily dosing for erectile dysfunction and once-daily use for benign prostatic hyperplasia. This long half-life distinguishes it from other PDE5 inhibitors. |
| Protein binding | Tadalafil is 94% bound to plasma proteins, primarily to albumin. The protein binding is independent of drug concentration over a wide range. |
| Volume of Distribution | The apparent volume of distribution (Vd/F) is approximately 63 L (or roughly 0.9 L/kg for a 70 kg individual), indicating distribution into tissues beyond the vascular space, including the penis and other target organs. |
| Bioavailability | Absolute oral bioavailability of tadalafil has not been formally determined; however, the drug is well absorbed after oral administration, with peak plasma concentrations reached in 0.5 to 6 hours (median 2 hours). Food does not affect the extent of absorption (AUC), though it may delay the rate (Tmax) by about 1–2 hours. |
| Onset of Action | Onset of clinical effect (erection sufficient for intercourse) is observed as early as 16 minutes after oral administration of a 10 mg or 20 mg dose, with median time to erection sufficient for intercourse of about 30 minutes across clinical trials. |
| Duration of Action | The clinical effect (ability to achieve and maintain erection) persists for up to 24 to 36 hours after a single oral dose (10 or 20 mg). This prolonged duration allows for increased spontaneity. For once-daily dosing (2.5 or 5 mg), continuous enhancement of erectile function is maintained. |
| Action Class | Phosphodiesterase-V inhibitors |
| Brand Substitutes | Tada 20mg Tablet, Tadact 20 Tablet, Tadovas 20mg Tablet, Bigfun 36 Tablet, Upwardz 20mg Tablet, Tadasure 10mg Tablet, Tadacip 10mg Tablet, Tadact 10 Tablet, Tadafil 10mg Tablet, Yaw 10 Tablet |
Tadalafil 10 mg or 20 mg orally as needed at least 30 minutes before sexual activity; maximum dosing frequency once daily. Alternative: 2.5 mg or 5 mg once daily for daily use.
| Dosage form | TABLET |
| Renal impairment | CrCl 30-50 mL/min: 5 mg once daily (max) for daily use; as-needed dosing: 10 mg not to exceed once every 48 hours. CrCl <30 mL/min: not recommended. Hemodialysis: not studied. |
| Liver impairment | Child-Pugh A and B: no dose adjustment necessary for as-needed dosing; daily use: caution, start at 5 mg once daily. Child-Pugh C: not recommended. |
| Pediatric use | Not indicated for pediatric patients under 18 years. |
| Geriatric use | No dose adjustment required solely based on age; consider renal function and concomitant medications. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for CIALIS (CIALIS).
| Breastfeeding | Excretion in human milk unknown. Not recommended for use in nursing mothers. M/P ratio not determined. |
| Teratogenic Risk | FDA Pregnancy Category B. Animal studies show no evidence of teratogenicity or embryotoxicity. No adequate, well-controlled studies in pregnant women. Risk cannot be ruled out; use only if clearly needed. |
| Fetal Monitoring | Monitor maternal blood pressure and heart rate due to vasodilatory effects. Fetal heart rate monitoring not routinely required but consider if maternal hypotension occurs. |
■ FDA Black Box Warning
None
| Serious Effects |
["Concomitant use of nitrates (any form) or riociguat","Hypersensitivity to tadalafil","Concomitant use with alpha-blockers (except for BPH with appropriate dosing)"]
| Precautions | ["Risk of hypotension with vasodilators or alpha-blockers","Contraindicated with nitrates due to severe hypotension risk","Patients with left ventricular outflow obstruction (e.g., aortic stenosis) should avoid use","Caution in patients with hypotension, severe hepatic impairment, or end-stage renal disease","Risk of priapism: advise immediate medical attention for erections lasting >4 hours","Decreased visual or hearing ability requiring discontinuation"] |
Loading safety data…
| Fertility Effects | In animal studies, no impairment of fertility at clinically relevant doses. In humans, transient decreases in sperm concentration and motility reported, but not clinically significant. |