Hello and Welcome to ‘Ask A Doctor’ service. I have reviewed your query and here is my advice. Excessive sweating in a patient who s taking Warfarin and Diltiazem can be attributed to many causes but I ll focus on these drugs first. Let me start with Warfarin, it increases the risk for gastrointestinal bleeding. If the bleeding is serious enough then the patient may experience dizziness, cold sweats, thirst, rapid heart rate, etc. Patients on Diltiazem may not experience tachycardia though because this drug reduces the heart rate. Diltiazem may cause low heart rate and hypotension. Both of them may sweating (cold sweats usually) and faintness if serious enough. Measuring the heart rate and blood pressure will confirm or exclude both of these assumptions. In any case excessive sweating that occurs without any good explanation is a good reason to visit the ER and you should insist on doing so. Hope I have answered your query. Let me know if I can assist you further.