The essential element for successful opioid detoxification or reduction is gradual tapering of the dose. Opioid withdrawal is generally not dangerous except in patients at risk from increased sympathetic tone, such as those with increased intracranial pressure or unstable angina. However, opioid withdrawl is very uncomfortable and distressing and can be much worse than the flu. I have never wanted to climb the walls when I have had the flu. That is ridiculous that they told you it was like having the flu. Some symptoms may be like the flu; runny nose, headache, nauseau, but, all of your symptoms are certainly not caused by thinking about it.
Tapering opioids often results in exacerbation of the patient's primary pain symptom (rebound pain). Increases in pain can occur even if the analgesic effects of opioid therapy had not been appreciable. Although it is generally not possible to avoid discomfort completely, the goal of detoxification is to ameliorate withdrawal.
There are several non-opioid drugs that are commonly used as adjunctive agents to provide additional relief from withdrawal symptoms. Clonidine can help relieve many of the autonomic symptoms of opioid withdrawal such as nausea, cramps, sweating, tachycardia and hypertension, which result from the loss of opioid suppression of the locus ceruleus during the withdrawal syndrome. Other meds include nonsterioidal anti-inflammatory drugs for muscle aches, Pepto-Bismol for diarrhea, anticholinergics for abdominal cramps, and antihistamines for insomnia and restlessness.
I have not read any studies about renal failure or kidney transplant patients who take oxy. However it seems to the the drug of choice for doc to prescribe in those cases.
I do believe you should be concerned with your heart and bp. I would call my cardio doc and explain what is going on and tell that doc who is trying to decrease your meds there are better ways as I have described above.