Safety, tolerability, and efficacy of overnight switching from sildenafil to tadalafil in patients with pulmonary arterial hypertension

Cardiovasc Ther. 2013 Oct;31(5):274-9. doi: 10.1111/1755-5922.12038.


Aims: Tadalafil, a once-daily phosphodiesterase type 5 inhibitor (PDE-5I), offers clinicians an alternative to sildenafil, a 3-times-daily (t.i.d.) PDE-5I for treatment of pulmonary arterial hypertension (PAH). However, there are limited data describing the risks and benefits or recommended methodology of switching patients from sildenafil to tadalafil.

Methods: Chart reviews were conducted on all World Health Organization group 1 patients on sildenafil for ≥ 3 months who transitioned to tadalafil with documented clinic visits and 6-min walk tests on both drugs. Most patients were transitioned by discontinuing sildenafil after the evening dose and initiating tadalafil 40 mg/day the next day. Data collected included demographics, PAH etiology, diagnostic hemodynamics, 6-min walk distance (6MWD), PDE-5I side effects, and concomitant medications. Data on B-type natriuretic peptide (BNP) levels were available for most patients also receiving endothelin receptor antagonists (ERAs).

Results: Medical records from 98 patients were evaluated. Most patients (92%) were on sildenafil for > 1 year, and 78% were receiving sildenafil 80-100 mg t.i.d. Ninety-seven percent of patients (95/98) were successfully transitioned and maintained on 40 mg/day. With a mean duration on tadalafil therapy of 243 ± 127 days at the time of analysis, 6MWD was unchanged. Patient-reported adverse events included headache (4%) and heartburn (2%). There was minimal change in BNP levels in the subset of patients receiving an ERA concomitantly.

Conclusions: Transition from sildenafil to tadalafil 40 mg/day appears feasible without clinical deterioration or intolerable side effects. This study provides guidance to physicians considering transition from sildenafil to tadalafil for selecting patients.

Keywords: Phosphodiesterase type 5 inhibitor; Pulmonary arterial hypertension; Retrospective; Sildenafil; Tadalafil; Transition.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Carbolines / adverse effects
  • Carbolines / therapeutic use*
  • Endothelin Receptor Antagonists
  • Familial Primary Pulmonary Hypertension
  • Female
  • Humans
  • Hypertension, Pulmonary / drug therapy*
  • Male
  • Middle Aged
  • Natriuretic Peptide, Brain / blood
  • Phosphodiesterase 5 Inhibitors / therapeutic use*
  • Piperazines / adverse effects
  • Piperazines / therapeutic use*
  • Purines / adverse effects
  • Purines / therapeutic use
  • Retrospective Studies
  • Sildenafil Citrate
  • Sulfones / adverse effects
  • Sulfones / therapeutic use*
  • Tadalafil


  • Carbolines
  • Endothelin Receptor Antagonists
  • Phosphodiesterase 5 Inhibitors
  • Piperazines
  • Purines
  • Sulfones
  • Natriuretic Peptide, Brain
  • Tadalafil
  • Sildenafil Citrate