The Effects of Topical Treatment With Clonidine + Pentoxifylline in Patients With Neuropathic Pain

Exclusion Criteria

• •1. Diabetes mellitus necessitating antihyperglycemic treatment or any other endocrine disease;
• •2. Any liver disease, resulting in aspartate aminotransferase (AST) levels greater than 3 times the normal values, or kidney disease, resulting in creatinine levels greater than 133 µmol/L;
• •3. Hypertension or taking of anti-hypertensive medication;
• •4. Malignant disease or taking of chemotherapeutic agents;
• •5. Known diagnosis of angina pectoris, arrhythmias, congestive heart failure or peripheral arterial disease;
• •6. Pregnancy or breast feeding. Female patients of child-bearing age must have a negative urine pregnancy test;
• •7. Known allergic reaction to clonidine or pentoxifylline;
• •8. Presence of major depression, bipolar affective disorder or schizophrenia;
• •9. Presence of a severe medical condition, or condition known to affect peripheral circulation (intermittent claudication, peripheral arterial disease, Raynaud's syndrome);
• •10. any medication that interacts with clonidine or pentoxifylline \[e.g. cardiovascular drugs such as angiotensin converting enzyme (ACE) inhibitors, alpha blockers (prazosin, terazosin or doxazosin), beta blockers (atenolol, metoprolol, propranolol), neuroleptics (butyrophenones, phenothiazines, thioxanthenes), calcium channel blockers (verapamil, diltiazem) and non-cardiovascular drugs such as diuretics, thyroxine, monoamine oxidase inhibitors and selective serotonin reuptake inhibitors (SSRIs), as well as vitamin K antagonists/blood thinners, such as warfarin\];
• •11. any medical condition that might be impacted by clonidine or pentoxifylline, such as cardiovascular disease, cardiac rhythm disorders (atrial-ventricular blockade or conduction abnormalities), orthostatic regulation disturbances, disorders of cerebral perfusion, chronic renal failure; sinus node dysfunction, or a recent cerebral and/or retinal haemorrhage.