Pulmonary embolism after tadalafil ingestion

Synthesis and Antiplatelet and Anticoagulant Activity of Thietane-Containing 2-(5-Bromo-2,4-Dihydro-3-Oxo-1,2,4-Triazolyl-4)Acetate Salts

Sulfone II was synthesized via oxidation of ethyl 2-[5-bromo-2,4-dihydro-3-oxo-2-(thietanyl-3)-1,2,4-triazolyl- 4]acetate (I) by H₂O₂. Hydrolysis of esters I and II synthesized 2-[5-bromo-2,4-dihydro- 3-oxo-2-(thietanyl-3)-1,2,4-triazolyl-4]- and 2-[5-bromo-2,4-dihydro-3-oxo-2-(1,1-dioxothietanyl-3)-1,2,4- triazolyl-4]acetic acids III and IV, respectively.Water-soluble salts V and VI were prepared by reacting acids III and IV with alkali-metal hydroxides and amines. The structures of the synthesized compounds were confirmed IR and NMR spectroscopic data. The antiplatelet and anticoagulant activity of the synthesized compounds was studied in vitro based on predictions of the PASS computer program. Compounds III and VIb, which showed the absence of predicted toxic risks and were superior to the reference drug in the collagen-induced aggregation test, had the most pronounced antiplatelet activity (comparable to that of acetylsalicylic acid) in the ADP-induced aggregation test. The anticoagulant activity of the compounds was significantly inferior to that of heparin sodium. All synthesized compounds satisfied Lipinski’s rule-of-5.

The Development of Cerebral Venous Thrombosis after Tadalafil Ingestion in a Patient with Antiphospholipid Syndrome

We report a case of cerebral venous thrombosis related to the ingestion of tadalafil. A 45-year-old man presented with posterior headache and was diagnosed with tension headache. Five days later, he was transported to our hospital via ambulance due to a tonic-clonic seizure. Head MRI showed cerebral venous thrombosis (CVT). He confessed to having recently taken a large doses of tadalafil. His anti-cardiolipin antibody and anti-caldiolipin-β2-glycoprotein-I complex antibody levels were elevated. Our case suggests the possibility that tadalafil is related to both cardiovascular complications and CVT in patients with hypercoagulability. Patients with conditions associated with hypercoagulability, including antiphospholipid syndrome may be better advised to avoid the use of tadalafil.

Oral therapies for pulmonary arterial hypertension: endothelin receptor antagonists and phosphodiesterase-5 inhibitors

The development of orally active pulmonary vasodilators has been a major breakthrough in the treatment of pulmonary arterial hypertension (PAH). Orally active medications greatly enhanced patient access to PAH treatment and increased an interest in the diagnosis and treatment of this disease that still continues. Four different orally active drugs are currently available for the treatment of PAH and several more are undergoing evaluation. This article discusses the mechanisms by which endothelin receptor antagonists and phosphodiesterase-5 inhibitors mitigate pulmonary hypertensive responses, and reviews the most recent data concerning their efficacy and limitations in the treatment of PAH.

A case of acute pulmonary thromboembolism after taking tadalafil

Tadalafil is a phosphodiesterase-5 inhibitor (PDE5I), which is widely used to treat erectile dysfunction. Although PDE5Is have excellent safety profiles, and most of the side effects are mild, rare serious adverse events have been reported in association with PDE5Is. Thrombosis is one of those events, and a few previous reports have suggested the association of PDE5Is with thrombosis. We report the case of a 61-year-old male who developed pulmonary embolism combined with pulmonary infarction directly after taking tadalafil. Both the patient and the physician suspected tadalafil as the culprit drug, as the patient was in an otherwise healthy condition. However, after extensive evaluation, we noticed that factor VIII levels were elevated. Prior reports suggesting the association between thrombosis and PDEIs either lack complete information on coagulation factors, or show inconsistencies in their results. Physicians should operate caution prior to accepting the diagnosis of adverse drug reaction.

Tadalafil for the treatment of pulmonary arterial hypertension

Tadalafil is a selective inhibitor of phosphodiesterase type-5 (PDE-5) that was originally developed for the treatment of male erectile dysfunction and recently approved for the treatment of pulmonary arterial hypertension (PAH). The antipulmonary hypertensive effects of nitric oxide and the natriuretic peptides are mediated via increasing intracellular cGMP and enzymatic degradation by PDE-5 is the major route of cGMP inactivation in the lung. Evidence is accruing that PDE-5 activity is increased in pulmonary vascular diseases and may contribute to the pathogenesis of PAH. The longer half-life of tadalafil allows for once-daily dosing as compared with three-times daily dosing for sildenafil, the only other PDE-5 inhibitor currently approved for treatment of PAH. This article reviews the role of cGMP and PDE-5 in PAH, presents the results of recent clinical trials and discusses the role of tadalafil in the treatment of this rare but difficult-to-treat disease.