(pen toks IF i lin)
Excipient information presented when available (limited, particularly for generics); consult specific product labeling. [DSC] = Discontinued product
Tablet Extended Release, Oral:
TRENtal: 400 mg [DSC] [contains benzyl alcohol]
Generic: 400 mg
Brand Names: U.S.
- TRENtal [DSC]
- Blood Viscosity Reducer Agent
Pentoxifylline increases blood flow to the affected microcirculation. Although the precise mechanism of action is not well-defined, blood viscosity is lowered, erythrocyte flexibility is increased, leukocyte deformability is increased, and neutrophil adhesion and activation are decreased. Overall, tissue oxygenation is significantly increased.
Hepatic to multiple metabolites; undergoes extensive first-pass effect; Pentoxifylline undergoes reduction to metabolite I (active), and oxidation to form metabolite V (active) (Ward 1987); Note: Plasma concentrations of M-1 and M-V are 5 and 8 times greater, respectively, than pentoxifylline
Urine (0% as unchanged, 50% to 80% as M-V metabolite, 20% as other metabolites); feces (<4%)
Onset of Action
2 to 4 weeks with multiple doses
Time to Peak
Serum: 2 to 4 hours
Parent drug: 24 to 48 minutes; Metabolites: 60 to 96 minutes
Special Populations: Renal Function Impairment
In patients with mild to moderate renal impairment, AUC0-tss and Cmax of the active Metabolite V increased 2.4- and 2.1-fold, respectively. In patients with severe renal impairment, the AUC0-tss and Cmax of active Metabolite V increased 12.9- and 10.6-fold, respectively. Twice daily administration increased the exposure to metabolite V only slightly in both groups.
Special Populations: Hepatic Function Impairment
Following a single dose of pentoxifylline, the AUC increased 6.5-fold and the Cmax increased 7.5-fold in patients with mild to moderate hepatic impairment, The AUC and Cmax of active Metabolite I also increased 6.9- and 8.2-fold, respectively. Studies were not conducted in patients with severe hepatic failure.
Special Populations: Elderly
Pentoxifylline: Increased AUC and decreased elimination rate (60 to 68 years of age).
Use: Labeled Indications
Intermittent claudication: Treatment of intermittent claudication on the basis of chronic occlusive arterial disease of the limbs.
Limitations of use: May improve function and symptoms, but not intended to replace more definitive therapy. Note: The American College of Chest Physicians (ACCP) discourages the use of pentoxifylline for the treatment of intermittent claudication refractory to exercise therapy (and smoking cessation) (Guyatt, 2012).
Severe alcoholic hepatitis; venous leg ulcers (with compression therapy)
Patients previously exhibiting intolerance to pentoxifylline, xanthines (eg, caffeine, theophylline), or any component of the formulation; recent cerebral and/or retinal hemorrhage
Canadian labeling: Additional contraindications (not in U.S. labeling): Acute MI, severe coronary artery disease when myocardial stimulation might prove harmful, peptic ulcers (current or recent)
Intermittent claudication: Oral: 400 mg 3 times daily; maximal therapeutic benefit may take 2 to 4 weeks to develop; recommended to maintain therapy for at least 8 weeks. May reduce to 400 mg twice daily if GI or CNS side effects occur; discontinue if side effects persist.
Note: Use for the treatment of intermittent claudication refractory to exercise therapy (and smoking cessation) has been discouraged by The American College of Chest Physicians (ACCP) (Guyatt, 2012).
Severe alcoholic hepatitis (Maddrey Discriminant Function [MDF] score ≥32, especially when corticosteroids contraindicated) (off-label use): Oral: 400 mg 3 times daily for 4 weeks (O’Shea, 2010)
Venous leg ulcer (off-label use): Oral: 400 mg 3 times daily (with compression therapy) (Jull, 2002; Robson, 2006)
Refer to adult dosing.
Dosing: Renal Impairment
Manufacturer's labeling: CrCl <30 mL/minute: 400 mg once daily
The following guidelines have been used by some clinicians:
Aronoff, 2007: Adults:
CrCl >50 mL/minute: 400 mg every 8 to 12 hours
CrCl 10-50 mL/minute: 400 mg every 12 to 24 hours
CrCl <10 mL minute: 400 mg every 24 hours
Hemodialysis: supplemental postdialysis dose is not necessary.
Peritoneal dialysis: 400 mg every 24 hours
Paap, 1996: Adults:
Moderate renal impairment (CrCl ~60 mL/minute): 400 mg twice daily.
Severe renal impairment (CrCl ~20 mL/minute): 400 mg once daily; further reduction may be required; Paap suggests 200 mg once daily, but with current products (extended or controlled release; unscored) may require adaptation to 400 mg once every other day.
Dosing: Hepatic Impairment
There are no dosage adjustments provided in manufacturer’s labeling; use with caution.
A 20 mg/mL oral suspension may be made using tablets. Crush ten 400 mg tablets and reduce to a fine powder. Add a small amount of purified water and mix to a uniform paste; mix while adding purified water to almost 200 mL; transfer to a calibrated bottle, rinse mortar with vehicle, and add quantity of vehicle sufficient to make 200 mL. Label "shake well" and "refrigerate". Stable 91 days.Nahata MC, Pai VB, and Hipple TF, Pediatric Drug Formulations, 5th ed, Cincinnati, OH: Harvey Whitney Books Co, 2004.
Administer with food. Swallow whole; do not chew, crush, or divide.
May be taken with meals.
Store between 20°C to 25°C (68°F to 77°F); protect from light.
Agents with Antiplatelet Properties (e.g., P2Y12 inhibitors, NSAIDs, SSRIs, etc.): Pentoxifylline may enhance the antiplatelet effect of Agents with Antiplatelet Properties. Monitor therapy
Blood Pressure Lowering Agents: Pentoxifylline may enhance the hypotensive effect of Blood Pressure Lowering Agents. Monitor therapy
Cimetidine: May increase the serum concentration of Pentoxifylline. Monitor therapy
CYP1A2 Inhibitors (Strong): May increase the serum concentration of Pentoxifylline. Monitor therapy
Heparin: Pentoxifylline may enhance the anticoagulant effect of Heparin. Monitor therapy
Heparin (Low Molecular Weight): Pentoxifylline may enhance the anticoagulant effect of Heparin (Low Molecular Weight). Monitor therapy
Ketorolac (Nasal): May enhance the adverse/toxic effect of Pentoxifylline. Specifically, the risk of bleeding may be increased. Avoid combination
Ketorolac (Systemic): May enhance the adverse/toxic effect of Pentoxifylline. Specifically, the risk of bleeding may be increased with this combination. Avoid combination
Theophylline Derivatives: Pentoxifylline may increase the serum concentration of Theophylline Derivatives. Exceptions: Dyphylline. Monitor therapy
TiZANidine: CYP1A2 Inhibitors (Weak) may increase the serum concentration of TiZANidine. Management: Avoid these combinations when possible. If combined use cannot be avoided, initiate tizanidine at an adult dose of 2 mg and increase in 2-4 mg increments based on patient response. Monitor for increased effects of tizanidine, including adverse reactions. Consider therapy modification
Vitamin K Antagonists (eg, warfarin): Pentoxifylline may enhance the anticoagulant effect of Vitamin K Antagonists. Monitor therapy
Concomitant administration increases theophylline levels
1% to 10%: Gastrointestinal: Nausea (2%), vomiting (1%)
<1% (Limited to important or life-threatening): Anaphylactic shock, anaphylactoid reaction, anaphylaxis, angioedema, angina pectoris, anorexia, aplastic anemia, aseptic meningitis, blurred vision, cardiac arrhythmia, chest pain, cholecystitis, conjunctivitis, decreased serum fibrinogen, depression, dyspnea, hallucination, hepatitis, hypotension, increased liver enzymes, jaundice, leukemia, leukopenia, pancytopenia, scotoma, seizure, tachycardia, thrombocytopenia
Concerns related to adverse effects:
• Anaphylaxis/anaphylactoid reactions: Discontinue at first sign of anaphylaxis or anaphylactoid reaction.
• Hepatic impairment: Use with caution in patients with mild to moderate hepatic impairment; the bioavailability of pentoxifylline and metabolite I is increased. Has not been studied in patients with severe hepatic disease.
• Renal impairment: Use with caution in patients with renal impairment; bioavailability of active metabolite V may be increased.
• Elderly: Use with caution in the elderly due to the potential for cardiac, hepatic, or renal impairment.
Renal function; hemoglobin/hematocrit in patients with risk factors for hemorrhage
Pregnancy Risk Factor
Adverse events have been observed in animal reproduction studies. Information related to use in pregnant women has not been located. Pentoxifylline may be used to test sperm viability when evaluating nonfertile males (ASRM, 2012). It has also been evaluated for the treatment of infertility due to endometriosis, but use for this purpose is not currently recommended (Lu, 2012).
• Discuss specific use of drug and side effects with patient as it relates to treatment. (HCAHPS: During this hospital stay, were you given any medicine that you had not taken before? Before giving you any new medicine, how often did hospital staff tell you what the medicine was for? How often did hospital staff describe possible side effects in a way you could understand?)
• Patient may experience burping, bloating, dizziness, flatulence, headache, vomiting, or nausea. Have patient report immediately to prescriber angina, arrhythmia, severe dizziness, or passing out (HCAHPS).
• Educate patient about signs of a significant reaction (eg, wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat). Note: This is not a comprehensive list of all side effects. Patient should consult prescriber for additional questions.
Intended Use and Disclaimer: Should not be printed and given to patients. This information is intended to serve as a concise initial reference for health care professionals to use when discussing medications with a patient. You must ultimately rely on your own discretion, experience, and judgment in diagnosing, treating, and advising patients.