Pentoxifylline

INTRODUCTION

Indications

Management of symptomatic peripheral vascular disease (intermittent claudication).

Action

↑ the flexibility of RBCs by increasing levels of cyclic adenosine monophosphate (cAMP). ↓ blood viscosity by inhibiting platelet aggregation and decreasing fibrinogen. Therapeutic Effects: ↑ blood flow.

Adverse Reactions/Side Effects

CNS: agitation, dizziness, drowsiness, headache, insomnia, nervousness. EENT: blurred vision. Resp: dyspnea. CV: angina, arrhythmias, edema, flushing, hypotension. GI: abdominal discomfort, belching, bloating, diarrhea, dyspepsia, flatus, nausea, vomiting. Neuro: tremor.

PHYSICAL THERAPY IMPLICATIONS

Examination and Evaluation

• Assess patient's walking distance and pain-free walking time. Document an increase in walking distance and time as an indication that this drug is helping reduce intermittent claudication.

• Assess heart rate, ECG, and heart sounds, especially during exercise (See Appendices G, H). Report any rhythm disturbances or signs of arrhythmias, including palpitations, chest discomfort, shortness of breath, dyspnea, fainting, and fatigue/weakness.

• Assess blood pressure (BP) periodically and compare to normal values (See Appendix F). Report low BP (hypotension), especially if patient experiences dizziness, fatigue, or other symptoms.

• Assess peripheral edema using girth measurements, volume displacement, and measurement of pitting edema (See Appendix N). Report increased swelling in feet and ankles due to peripheral vasodilation.

• Monitor personality changes, including agitation or nervousness. Notify physician if these changes become problematic.

• Assess dizziness or drowsiness that might affect gait, balance, and other functional activities (See Appendix C). Report balance problems and functional limitations to the physician, and caution the patient and family/caregivers to guard against falls and trauma.

Interventions

• Implement therapeutic exercises and ambulation activities to augment the effects of drug therapy and promote increased walking distance. Patients should attempt to walk as long as possible after the onset of leg pain and progressively increase the time spent walking before stopping due to claudication.

• Because of the risk of arrhythmias and abnormal BP responses, use caution during aerobic exercise and other forms of therapeutic exercise. Assess exercise tolerance frequently (BP, heart rate, fatigue levels), and terminate exercise immediately if any untoward cardiac responses occur (See Appendix L).

Patient/Client-Related Instruction

• Instruct patient to report other bothersome side effects such as severe or prolonged headache, sleep loss, blurred vision, tremor, or GI problems (nausea, vomiting, diarrhea, abdominal pain, belching, bloating, indigestion, flatulence).

Pharmacokinetics

Absorption: Well absorbed following oral administration.

Distribution: Bound to RBC membrane. Enters breast milk.

Metabolism and Excretion: Metabolized by RBCs and the liver.

Half-life: 25–50 min.