| Drug ID: | D266 |
| Drug Name: | Pentoxifylline |
| Synonyms: |
PTX; Oxpentifylline
|
| Type: | Chemical drug |
| DrugBank ID: |
DB00806
|
| DrugBank Description: |
Pentoxifylline (PTX) is a synthetic dimethylxanthine derivative that modulates the rheological properties of blood and also has both anti-oxidant and anti-inflammatory properties. Although originally developed to treat intermittent claudication, a form of exertion-induced leg pain common in patients with peripheral arterial disease, PTX has been investigated for its possible use in diverse conditions, including osteoradionecrosis, diabetic kidney disease, and generally any condition associated with fibrosis. More recently, PTX has been suggested as a possible treatment for COVID-19-induced pulmonary complications due to its ability to regulate the production of inflammatory cytokines.
Pentoxifylline has been marketed in Europe since 1972; PTX extended-release tablets sold under the trade name TRENTAL by US Pharm Holdings were first approved by the FDA on Aug 30, 1984, but have since been discontinued. A branded product, PENTOXIL, marketed by Upsher-Smith Laboratories, and generic forms marketed by Valeant Pharmaceuticals and APOTEX have been available since the late 1990s.
|
| PubChem ID: |
4740
|
| CasNo: |
6493-05-6
|
| Repositioning for NAFLD: |
Yes
|
| SMILES: |
O=c1c2c(n(c(=O)n1CCCCC(=O)C)C)ncn2C
|
| Structure: |
|
| InChiKey: |
BYPFEZZEUUWMEJ-UHFFFAOYSA-N
|
| Molecular Weight: |
278.312
|
| DrugBank Targets: |
Adenosine receptor A2a agonist; Phosphodiesterase enzymes inhibitor; Adenosine receptor A1; 5'-nucleotidase inhibitor
|
| DrugBank MoA: |
Patients with peripheral arterial disease (PAD) may suffer from intermittent claudication, exertional leg pain that resolves upon rest, which is underscored by a complex etiology including vascular dysfunction (reduced limb perfusion, angiogenesis, and microcirculatory flow), systemic inflammation, and skeletal muscle dysfunction. Pentoxifylline (PTX), (3,7-dimethyl-1-(5-oxohexyl)-3,7-dihydro-1H-purine-2,6-dione) or 1-(5-oxohexyl)-3,7-dimethylxanthine, is a methyl-xanthine derivative that acts to lower blood viscosity by increasing erythrocyte flexibility, reducing plasma fibrinogen, inhibiting neutrophil activation, and suppressing erythrocyte/platelet aggregation; it also has antioxidant and anti-inflammatory effects. Although the precise mechanism of action has yet to be elucidated, numerous studies have suggested several effects of PTX.
The classical interpretation of PTX's broad effects is due to its ability to act, _in vitro_, as a non-specific cyclic-3',5'-phosphodiesterase (PDE) inhibitor at millimolar concentrations; specifically, it has been proposed that inhibition of PDE type III and IV isozymes leads to elevated cyclic adenosine monophosphate (cAMP) levels, which mediate diverse downstream effects. This view has been challenged, specifically by observing those plasma concentrations of PTX in routine clinical use are typically only around 1μM, far lower than those used to inhibit PDEs _in vitro_. Instead, several studies have suggested that PTX can modulate adenosine receptor function, specifically the Gα-coupled A2A receptor (A2AR). Whether PTX acts directly as an A2AR agonist is unclear, although it can clearly increase the response of A2AR to adenosine. A2AR activation activates adenylyl cyclase, which increases intracellular cAMP levels; this observation may explain PTX's ability to increase intracellular cAMP in a PDE-independent fashion.
Elevated cAMP levels have numerous downstream effects. cAMP-mediated activation of protein kinase A (PKA) suppresses nuclear translocation of NF-κB, which suppresses transcription of pro-inflammatory cytokines such as tumour necrosis factor (TNF-α), interleukin-1 (IL-1), and IL-6 as well as TNF-induced molecules such as adhesion molecules (ICAM1 and VCAM1) and the C-reactive protein (CRP). PTX has also been shown to prevent the downstream phosphorylation of p38 MAPK and ERK, which are responsible for assembling the NADPH oxidase involved in the neutrophil oxidative burst. This effect is due to a PKA-independent decrease in Akt phosphorylation and a PKA-dependent decrease in phosphorylation of p38 MAPK and ERK. This transcriptional regulation at least partially explains the anti-inflammatory and anti-oxidative properties of PTX.
Also, activated PKA can activate the cAMP response element-binding protein (CREB), which itself blocks SMAD-driven gene transcription, effectively disrupting transforming growth factor (TGF-β1) signalling. This results in lower levels of fibrinogenic molecules such as collagens, fibronectin, connective tissue growth factor, and alpha-smooth muscle actin. Hence, disruption of TGF-β1 signalling may explain the anti-fibrotic effects of PTX, including at least some of the decrease in blood viscosity.
The picture is complicated by the observation that PTX metabolites M1, M4, and M5 have been shown to inhibit C5 Des Arg- and formyl-methionylleucylphenylalanine-induced superoxide production in neutrophils and M1 and M5 significantly contribute to PTX's observed hemorheological effects. Overall, PTX administration is associated with decreased pro-inflammatory molecules, an increase in anti-inflammatory molecules such as IL-10, and decreased production of fibrinogenic and cellular adhesion molecules.
|
| DrugBank Pharmacology: |
Pentoxifylline, a synthetic dimethylxanthine derivative structurally related to and , exhibits hemorheological, anti-oxidative, and anti-inflammatory properties and is traditionally indicated in the treatment of peripheral arterial disease (PAD). In PAD patients with concurrent cerebrovascular and coronary artery diseases, pentoxifylline treatment has occasionally been associated with angina, arrhythmia, and hypotension. Concurrent use with should be associated with more frequent monitoring of prothrombin times. Also, patients with risk factors complicated by hemorrhages, such as retinal bleeding, peptic ulceration, and recent surgery, should be monitored periodically for bleeding signs.
|
| DrugBank Indication: |
Pentoxifylline is indicated for the treatment of intermittent claudication in patients with chronic occlusive arterial disease. Pentoxifylline may improve limb function and reduce symptoms but cannot replace other therapies such as surgical bypass or removal of vascular obstructions.
|
| Targets: |
ADORA2A antagonist; ADORA1 antagonist; PDE4A inhibitor; PDE3B inhibitor; PDE4B inhibitor; PDE5A inhibitor; PDE8A inhibitor; PDE4C inhibitor; PDE11A inhibitor; PDE7A inhibitor; PDE7B inhibitor; PDE4D inhibitor; PDE3A inhibitor
|
| Therapeutic Category: |
Anti-inflammatory; Cardiovascular drug
|
| Clinical Trial Progress: |
Phase 3 on-going (NCT05284448)
|
| Latest Progress: |
Under clinical trials
|
