TRENTAL
Clinical safety rating: caution
Comprehensive clinical and safety monograph for TRENTAL (TRENTAL).
Pentoxifylline, a methylxanthine derivative, improves blood flow by decreasing blood viscosity and increasing erythrocyte flexibility via inhibition of phosphodiesterase and increasing cAMP levels. It also inhibits platelet aggregation and has anti-inflammatory properties.
| Metabolism | Hepatic via erythrocyte metabolism and liver enzymes (CYP1A2, CYP2E1); active metabolites (metabolite-1 and metabolite-5). |
| Excretion | Renal: approximately 60-70% as metabolites; biliary/fecal: approximately 20-30% |
| Half-life | Terminal half-life: 0.4-0.8 hours for pentoxifylline; significant active metabolites (Metabolite I and V) have half-lives of 1-1.6 hours. Duration of clinical effect requires repeated dosing due to short half-life. |
| Protein binding | Pentoxifylline: 50-60% bound to plasma proteins; Metabolite I: 50-70% bound; Metabolite V: 50-70% bound. |
| Volume of Distribution | Pentoxifylline: Vd approximately 2-3 L/kg; extensive tissue distribution. |
| Bioavailability | Oral: 10-30% bioavailability due to extensive first-pass metabolism; IV: 100%. |
| Onset of Action | Oral: onset of clinical effect (improved blood flow) occurs within 2-4 weeks of therapy; IV: immediate hemodynamic effects within minutes. |
| Duration of Action | Oral: duration of single dose effect is 4-6 hours due to rapid elimination; sustained effect requires multiple daily doses. IV: effects last for 2-4 hours. |
400 mg orally three times daily with meals. Extended-release tablets should be swallowed whole, not crushed or chewed.
| Dosage form | TABLET, EXTENDED RELEASE |
| Renal impairment | For GFR < 30 mL/min, reduce dose to 400 mg orally once daily. No adjustment for GFR ≥ 30 mL/min. |
| Liver impairment | No specific dose adjustments for hepatic impairment. Use with caution in severe hepatic impairment (Child-Pugh C) due to increased systemic exposure; consider dose reduction based on tolerability. |
| Pediatric use | Not recommended for pediatric patients due to lack of safety and efficacy data. |
| Geriatric use | No specific dose adjustment required; monitor for adverse effects (e.g., hypotension, arrhythmias) due to age-related decline in renal function and increased sensitivity. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for TRENTAL (TRENTAL).
| Breastfeeding | Excreted in human milk; M/P ratio not established. Caution advised; discontinue nursing or drug based on importance to mother. |
| Teratogenic Risk | FDA Pregnancy Category C. No adequate studies in pregnant women; animal studies show fetal abnormalities at high doses. First trimester: risk cannot be ruled out. Second and third trimesters: use only if benefit outweighs potential fetal risk. |
| Fetal Monitoring |
■ FDA Black Box Warning
None
| Common Effects | Bloating Diarrhea Flushing sense of warmth in the face ears neck and trunk Headache Heartburn Lightheadedness Nausea Stomach discomfort Vomiting Weakness |
| Serious Effects |
["Intolerance or hypersensitivity to pentoxifylline or other methylxanthines (e.g., caffeine, theophylline).","Recent cerebral and/or retinal hemorrhage.","Concurrent use of theophylline (potential for increased toxicity)."]
| Precautions | ["Risk of bleeding: increases bleeding risk, especially in patients with recent hemorrhage, peptic ulcer, or on anticoagulants/antiplatelet agents.","Cardiovascular: use with caution in patients with coronary artery disease or hypotension.","Renal impairment: dose adjustment needed in severe impairment (CrCl <30 mL/min).","Geriatric: lower doses recommended due to increased systemic exposure."] |
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| Monitor maternal blood pressure, heart rate, and signs of bleeding. Fetal monitoring not specifically required but consider ultrasound if maternal hypotension occurs. |
| Fertility Effects | No known adverse effects on fertility in animal studies; no human data. |