Tadalafil

Generic Details

Generic Name

Tadalafil

Other Names

  • Cialis
  • Adcirca

Drug Class

  • Phosphodiesterase Type 5 Inhibitor

Chemical Formula

C22H19N3O4

Molecular Weight

389.404 g/mol

Mechanism of Action

  • Inhibits the enzyme phosphodiesterase type 5, leading to increased levels of cyclic guanosine monophosphate (cGMP) in the corpus cavernosum of the penis. This results in smooth muscle relaxation and increased blood flow, aiding in the treatment of erectile dysfunction.

Indications

  • Erectile dysfunction
  • Benign prostatic hyperplasia
  • Pulmonary arterial hypertension

Common Dosage Forms

  • Tablet

Typical Dosage

  • 5-20 mg once a day, as needed for erectile dysfunction
  • 2.5-5 mg once a day for benign prostatic hyperplasia
  • 40 mg once a day for pulmonary arterial hypertension

Pediatric Dosage

    Geriatric Dosage

      Side Effects

      • Headache
      • Flushing
      • Dyspepsia
      • Nasal congestion
      • Back pain
      • Muscle aches
      • Prolonged erections (priapism)
      • Vision changes

      Contraindications

      • Use of nitrates (nitroglycerin) in any form
      • Hypersensitivity to tadalafil
      • Concomitant use of alpha-blockers in some patients

      Pregnancy Category

      • Not applicable (not indicated for use in women)

      Lactation Safety

      • Not applicable (not indicated for use in women)

      Drug Interactions

      • Nitrates
      • Alpha-blockers
      • Antihypertensives
      • CYP3A4 inhibitors (e.g., ketoconazole, ritonavir)

      Overdose Symptoms

      • Headache
      • Dizziness
      • Priapism
      • Hypotension

      Antidote for Overdose

      • No specific antidote, symptomatic treatment

      Storage Conditions

      • Store at room temperature (15-30°C)
      • Protect from moisture and light

      Pharmacokinetics

      • Absorption: Rapidly absorbed after oral administration
      • Distribution: Extensively distributed in tissues
      • Metabolism: Primarily metabolized by CYP3A4 in the liver
      • Excretion: Excreted mainly in feces (61%) and urine (36%)

      Precautions

      • Caution in patients with cardiovascular disease
      • Caution in hepatic impairment
      • Avoid grapefruit juice consumption
      • Avoid alcohol consumption

      Warnings

      • Risk of hypotension with concomitant use of nitrates
      • Priapism may occur; seek immediate medical attention

      Others

      • Tadalafil has a long duration of action, up to 36 hours, allowing for more flexibility in timing of sexual activity.