Drugs and the Kidneys

As the kidneys help to filter wastes (including drugs) from the blood, the tiny filtering units, each of which is called a glomerulus, get exposed to high concentrations of drugs as part of the filtering process. As a result, the glomerulus is vulnerable to drug toxicity.

Also, the kidneys normally receive about 25% of the blood supply, and as blood carries medicines, these can also accumulate in the kidney.

Therefore, a huge range of drugs has the potential to cause kidney damage. The types of damage to kidney cells (nephrons) and their filtering tubes can vary, but here are some examples of the results of drug toxicity on nephrons:

• reduced energy output
• excessive production of damaging molecules
• damage to the surface of cells
• dehydration
• death of the tubes used by the kidney to eject wastes or reabsorb nutrients

In some cases, signs or symptoms of kidney injury will at first be subtle.

Drugs and the Kidneys -- Caution

Below is a list of some drugs and herbs with the potential to cause kidney injury; in some cases this problem is rare. In the case of the listed herbs, kidney toxicity can be severe and readers should avoid using the specific herbs or ingredients listed. For the listed drugs, in general, most otherwisehealthy HIV positive people should not have severe or life-threatening kidney problems as a result of taking these drugs. However, some of these drugs are used in very ill people, and in such cases kidney toxicity can occur. Note that this list is not exhaustive:

• Antibiotics: Several groups, or classes, of antibiotics have the potential to injure the kidneys, including the following:
  • aminoglycosides -- amikacin, gentamycin, spectinomycin
  • cephalosporins -- ciprofloxacin (Cipro)
  • sulfa drugs -- Bactrim/Septra (trimethoprim-sulfamethoxazole)
• Antidepressants -- lithium
• Antifungal drugs -- amphotericin B
• Antiseizure drugs -- valproic acid
• Antiviral drugs -- acyclovir or valacyclovir, adefovir (Hepsera), cidofovir (Vistide), tenofovir (Viread and in Truvada and Atripla), foscarnet (Foscavir) and indinavir (Crixivan)
• Chinese herbs that contain aristolochic acid. These are found in herbs of the Aristolochia species. Some herbal remedies that contain aristolochic acid includeMu-Tong and Fangchi.
• Blood pressure medicines such as ACE inhibitors (angiotensin converting enzyme), including: benazepril, cilazapril, fosinopril, lisinopril, quinapril, ramipril (Altase), perindopril, trandolopril
• Illicit drugs -- cocaine, heroin
• Immunomodulators -- interleukin-2 and interferon (Pegasys and Pegetron)
• Lipid-lowering medications -- rosuvastatin (Crestor)
• Pain medications -- acetaminophen (Tylenol), ibuprofen (Advil,Motrin) and some drugs used to treat inflammation
• Transplant medicines -- cyclosporine, tacrolimus

Because initial kidney injury can be mild, regular monitoring of the kidneys is necessary when these drugs are prescribed. It is important to stay hydrated, drinking at least a litre of healthful fluids -- water, juice, herbal teas -- each day. Liquids containing alcohol or caffeine increase the need for drinking more water.

References

1. Himmelfarb J, Joannidis M, Molitoris B, et al. Evaluation and initial management of acute kidney injury. Clinical Journal of the American Society of Nephrology. 2008 Jul;3(4): 962-7.
2. Pannu N, NadimMK. An overview of drug-induced acute kidney injury. Critical Care Medicine. 2008 Apr;36(4 Suppl):S216-23.
3. Guo X and Nzeure C. How to prevent, recognize, and treat drug-induced nephrotoxicity. Cleveland Clinic Journal of Medicine. 2002 Apr;69(4):289-312.
4. Harris G. Ban is advised on two top pills for pain relief. The New York Times. July 1, 2009, page A1.
5. Winston J, Deray G, Hawkins T. Kidney disease in patients with HIV infection and AIDS. Clinical Infectious Diseases. 2008 Dec 1;47(11):1449-57.

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