PENTOXIFYLLINE
| PENTOXIFYLLINE (pen-tox-i'fi-leen) Pentoxil, Trental Classifications: blood former; hemorrheologic agent; antiplatelet agent; Therapeutic: red blood cell modifier; blood viscosity improver Pregnancy Category: C |
Availability
400 mg sustained release tablets
Action
Useful in restoration of blood flow through capillary microcirculation that has been compromised by structural and flow dynamic changes in cerebral and peripheral vascular disorders. Action of pentoxifylline on maintaining the flexibility of RBCs appears to be related to an increase in erythrocyte cAMP activity, thus allowing erythrocyte membranes to maintain its integrity and become more resistant to deformity. Improvement in blood viscosity results in increased blood flow to the microcirculation and enhanced tissue oxygenation.
Therapeutic Effect
Decreased blood viscosity and improved blood flow, with consequent reduction of tissue hypoxia in extremities and the cerebrum. Results in increased blood flow to the extremities, reduced pain and paresthesia of intermittent claudication.
Uses
Intermittent claudication associated with occlusive peripheral vascular disease; diabetic angiopathies.
Unlabeled Uses
To improve psychopathologic symptoms in patient with cerebrovascular insufficiency and to reduce incidence of stroke in the patient with recurrent TIAs.
Contraindications
Intolerance to pentoxifylline or to methylxanthines (caffeine and theophylline); intracranial bleeding; retinal bleeding; pregnancy (category C), lactation. Safety in children <18 y is not established.
Cautious Use
Angina, hypotension, arrhythmias, cerebrovascular disease; peptic ulcer disease; renal failure; renal impairment; risk of bleeding; lactation.
Route & Dosage
| Intermittent Claudication Adult: PO 400 mg t.i.d. with meals |
Administration
Oral- Give on an empty stomach or with food; be consistent with time of day and relationship to food in establishing the daily regimen.
- Store tablets at 15°–30° C (59°–86° F).
Adverse Effects (≥1%)
Body as a Whole: Fever, flushing, convulsions, somnolence, loss of consciousness. CNS: Agitation, nervousness, dizziness, drowsiness, headache, insomnia, tremor, confusion. CV: Angina, chest pain, dyspnea, arrhythmias, palpitations, hypotension, edema, flushing. Eye: Blurred vision, conjunctivitis, scotomas. GI: Abdominal discomfort, belching, flatus, bloating, diarrhea, dyspepsia, nausea, vomiting. Skin: Brittle fingernails, pruritus, rash, urticaria. Other: Earache, unpleasant taste, excessive salivation, leukopenia, malaise, sore throat, swollen neck glands, weight change.Interactions
Drug: Ciprofloxacin, cimetidine may increase levels and toxicity, warfarin may have additive effects.Pharmacokinetics
Absorption: Readily from GI tract; 10–50% reaches systemic circulation (first pass metabolism). Peak: 2–4 h. Distribution: Distributed into breast milk. Metabolism: In liver and erythrocytes. Elimination: Primarily in urine. Half-Life: 0.4–0.8 h.Nursing Implications
Assessment & Drug Effects
- Monitor therapeutic effectiveness which is indicated by relief from pain and cramping in calf muscles, buttocks, thighs, and feet during exercise and improves walking performance (time and duration).
- Monitor BP if patient is also on antihypertensive treatment. Drug may slightly decrease an already stabilized BP, necessitating a reduced dose of the hypotensive drug.
Patient & Family Education
- Consult physician to determine CV status and capacity before reestablishing walking as exercise.
- Pay particular attention to care of the feet because of arterial insufficiency (diminished perfusion to feet).
- Be aware that bleeding and prolonged PT/INR associated with this treatment have been reported. Report promptly unexplained bleeding, easy bruising, nose bleed, pinpoint rash to physician.
- Avoid driving or working with hazardous machinery until drug response has stabilized because of potential for tiredness, blurred vision, dizziness.
Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; 
Canadian drug name; 
Prototype drug