Analgesics are commonly used in the home and are easily available over-the-counter in pharmacies. Many elderly people suffering from back and leg pain, as well as toothache, neuralgia, muscle and joint pain, often buy analgesic drugs on their own without the guidance of a doctor, thus laying the root of the problem. This leads to analgesic nephropathy, which is common and should be a cause for alarm.
Analgesic nephropathy is a chronic tubulointerstitial damage and/or renal papillary necrosis caused by long-term abuse of analgesic drugs with an accumulation of more than 1 to 2 kg, which is called analgesic nephropathy or analgesic-induced chronic tubulointerstitial nephritis.
Drugs commonly used to cause analgesic nephropathy include acetaminophen, aspirin, finasteride, ibuprofen, and phentermine, and are often a mixture of several analgesics. The disease occurs in women aged 40 to 60 years, with a female to male ratio of 3:1 to 6:1. The number of people abusing analgesics correlates with the incidence of analgesic nephropathy, and the number of people using analgesics for many years correlates with the incidence of renal disease.
I. Diagnosis.
Analgesic nephropathy should be considered in any patient with chronic renal failure who takes analgesics for a long time and has multiple complaints of physical discomfort. If there is a history of long-term clinical abuse of analgesics with cumulative amount greater than 1-2 kg, clinical manifestations of interstitial nephritis and renal papillary necrosis, i.e. polyuria, nocturia, sodium loss nephritis, tubular acidosis, aseptic pyuria with renal insufficiency; detached necrotic renal papillary tissue found in urine; annular shadow of renal papillary necrosis seen on intravenous pyelogram; accompanied by fever, hematuria, acute back pain, urinary colic and The diagnosis of analgesic nephropathy can be made when renal biopsy suggests chronic tubular interstitial inflammation with glomerulosclerosis and ultrasonography reveals typical wreath-like renal papillae calcification around the renal sinus.
Second, laboratory tests.
1, urine examination routine urine examination may have white blood cells, sterile pus urine, with obvious microscopic hematuria or meatus hematuria, hematuria often suggests stones, urinary tract epithelial tumor, interstitial cystitis, renal papillary necrosis or malignant hypertension, heterogeneous red blood cells suggest glomerular damage. Mild proteinuria is usually seen, with 24h urine protein quantification <2g, predominantly low-molecular proteinuria, sometimes up to the degree of nephropathy, with proteinuria up to 3.0g/d, often mixed, microglobular, tubular and β2-microglobulinuria, the latter being the hallmark of tubular proteinuria. Urine cytology is useful in detecting urothelial tumors. Urine glucose may be positive.
2. Poor urine concentration and dilution test function of renal tubular function examination, increased urinary amino acids and bicarbonate, urinary pH>6, and decreased urinary titratable acid. Urinary N-acetyl-β-D-glucosidase (NAG) concentration is increased, and urinary retinol binding protein (RBP) concentration is increased.
Third, other ancillary tests.
1, renal biopsy examination pathological changes to chronic interstitial nephritis manifestations, microscopically visible in the renal interstitium diffuse lymphocyte and monocyte infiltration, accompanied by fibrosis, tubular degeneration, atrophy, intimal thickening of small renal arteries, luminal narrowing, small vessel sclerosis, glomerular ischemic atrophy, periglomerular fibrosis, renal papillary necrosis and calcified foci can occur. The specific pathological change of painkiller nephropathy is superficial capillary sclerosis of the urinary tract mucosa, which is seen as uniform thickening of the capillary basement membrane with Schiff’s (Schiff) staining of periodate.
2, imaging examination of the urinary tract X-ray examination in the early stage shows widening of the renal pelvis, blunting of the calyx cup, and in the late stage, the typical manifestation of renal papillary necrosis, filling defect of the renal pelvis and calyx, so that the contrast agent enters the renal parenchyma and surrounds the renal papilla and forms a typical ring-shaped shadow. Intravenous pyelogram may also show shrunken kidneys, cortical atrophy, and in some cases, renal papillary necrosis. Abdominal plain film can show renal calcification.
3. Ultrasonography can reveal typical wreath-like renal papillary calcification around the renal sinus.
IV. Case analysis
Master Pan suffers from gouty arthritis. When he has an attack of joint pain, in addition to allopurinol and colchicine, he always takes analgesics such as anti-inflammatory pain, ibuprofen or fenpropathrin to relieve the pain. This year, he had recurrent gout attacks, he took analgesics every day to prevent pain, but not long ago, his family said that he did not look good, and at the same time, Master Pan often felt weak, dry mouth, but also weight loss, increased nocturnal urination, and hematuria, occasionally accompanied by frequent urination, urinary urgency, sterile pus urine and other phenomena. After a series of biochemical tests at the hospital, Master Pan found not only anemia, but also renal insufficiency, and ultrasound also found that both kidneys were shrunken, with thinning cortex and poor surface finish. After diagnosis, Mr. Pan suffered from “analgesic kidney damage”.
V. Treatment
The key to the treatment of this disease is early diagnosis, timely discontinuation of drugs, and protection of kidney function. Maintaining a certain amount of urine should ensure that the patient’s rehydration, so that the urine volume is maintained at more than 2000ml/d, thus increasing the excretion of drugs, reducing the concentration of drugs in the renal medulla, and reducing renal damage. Prevention and treatment of infection should pay attention to the prevention of infection, so as not to aggravate renal damage, once the infection is found should actively use low toxicity or non-toxic antibiotics.
For those who already have chronic renal insufficiency should be given dietary control and drug therapy, non-dialysis therapy, such as packaged aldehyde oxidation precipitated starch, essential amino acids intravenous drip, rhubarb preparations, etc. If necessary, dialysis treatment or renal transplantation. Correction of water-electrolyte disorders and acidosis For those with water and electrolyte disorders and acidosis, 5% sodium bicarbonate (125-250ml/d for 1-3 days) should be given promptly, and attention should be paid to blood volume replenishment.
Symptomatic supportive therapy should be actively anti-hypertensive, choose converting enzyme inhibitors, such as Captopril (Captopril) 25mg, 3 times / d, oral. Enalapril (Enalapril), 10mg, 1 time/d, orally; or Benadryl (Lortin), 5-10mg, 1 time/d, orally, etc. Try to avoid or use diuretics carefully. In the event of renal papillary necrosis causing urinary tract obstruction, treatment such as antispasmodic and rehydration should be given, and surgery is required to remove the necrotic tissue if it is ineffective.
If the obstruction is caused by blood clot, alkaline medication (5% sodium bicarbonate 250ml intravenous drip) should be given, and if the obstruction is caused by stone, ultrasonic lithotripsy or surgical treatment should be performed. In urgent cases, fistula surgery should be performed above the obstruction. If the obstruction is combined with infection, effective antibiotic treatment should be chosen. If the urinary tract obstruction has caused renal failure or even anuria, dialysis treatment can be given to make the patient’s condition improve and then release the obstructing factor.
Sixth, choose painkillers carefully
At present, the commonly used painkillers are mainly the following categories.
The first category is non-steroidal anti-inflammatory drugs, representing drugs such as aspirin and Fenbid. Such drugs have the potential to cause gastric bleeding, so patients with serious stomach problems are not suitable for use. For example, this is the case of Uncle Zhang in the previous example. In recent years, with the development of the pharmaceutical industry, some emerging non-steroidal drugs have gradually come into view, these drugs greatly reduce the side effects of the gastrointestinal tract, patients with serious gastric disease should be carefully selected.
The second category is the central painkillers represented by tramadol, such drugs have less stimulation for the gastrointestinal tract and no addiction, which can be used by patients who cannot tolerate non-steroidal drugs. However, their pain-relieving effects are strong and can only be used as second-line drugs.
The third category is the familiar opioid painkillers, such as dulcolax, morphine and so on. These drugs have strong analgesic effects and are highly addictive, so they are only used to relieve pain in patients with advanced cancer.
With so many drugs, how should patients choose them? Patients using painkillers can be broadly divided into the following two categories: one is neck, shoulder, back and leg pain, which is common in life. For such patients, non-steroidal drugs are preferred, and for patients with serious stomach problems, non-steroidal drugs that do not stimulate the gastrointestinal tract can be used, and only when the use of non-steroidal drugs is ineffective, central painkillers are considered. And opioid painkillers cannot be used for such patients. Another category is advanced cancer patients, whose pain relief needs to follow the “principle of ladder treatment”, from NSAIDs to central analgesics, and finally opioids, which is fundamentally different from ordinary patients.
Some people think that herbal medicines have little toxic side effects, so they take them for a long time, which is actually a misconception. In fact, like thunderbolt, poppy shells, raw herbaceous wormwood, pseudostellaria, broad antibiotics, etc., such herbs are certain toxicity, the regular hospital Chinese medicine will limit the dose, according to the course of prescription, to reduce the damage to the human body, but do not listen to medical advice, or to the irregular hospital, it is possible to delay treatment, or long-term overdose of herbal painkillers and cause kidney damage.
Seven, painkiller nephropathy prevention and control
When patients are diagnosed with painkiller nephropathy, they should first stop taking all drugs and non-hormonal anti-inflammatory drugs, especially painkillers, and disable drugs with nephrotoxicity to avoid aggravation of kidney damage. In patients with a definite history of urinary tract obstruction, surgical removal of the detached renal papilla tissue may be used. Then an aggressive treatment plan is adopted to treat both the symptoms and the root cause. However, there are many patients who have become addicted to painkillers due to long-term use of painkillers, so more attention should be paid to psychiatric support therapy along with pharmacological treatment to quit patients’ dependence on painkillers.
Therefore, after knowing the dangers of painkiller abuse, we should resolutely avoid abusing painkillers and should take them under the guidance of physicians. When taking painkillers, we should pay attention to drinking more water to increase the amount of urine, improve the solubility of drugs and avoid precipitation of crystals that can damage kidney tissues. Those who take painkillers for a long time should have a comprehensive urinary system examination regularly. Once there is an increase in nocturia, mild anemia and elevated blood pressure, it is necessary to go to the hospital for early treatment to prevent the occurrence and aggravation of painkiller nephropathy.