Drug induced nephrotoxicity

1. Presentation by SAQIB ZAMAN
4th prof
clinical clerkship

2. Drug induced Nephrotoxicity

3. What is Nephrotoxicity:
Nephrotoxicity is toxicity in the kidneys. It is a
poisonous effect of some substances, both
toxic chemicals and medications, on renal
function.
Toxicity produced due to certain drugs is called
Drug induced nephrotoxicity.

4. Drugs are a common source of acute kidney
injury. drugs shown to cause
nephrotoxicity exert their toxic effects by one
or more common pathogenic
mechanisms. Drug-induced
nephrotoxicity tends to be more common
among certain patients and in specific clinical
situations.

5. Risk Factors
Patient related factors:
• Age,
• sex,
• race
• Pre-existent renal disease
• Specific disease (diabetes mellitus, multiple
myeloma, proteinuric patients)
• Sodium-retaining states (cirrhosis, heart failure,
nephrosis)
• Dehydration and volume depletion

6. Risk factors
• Acidosis, potassium and magnesium depletion
• Hyperuricemia,
• Hyperuricosuria
• Sepsis
• shock
• Renal transplantation

7. Risk factors
Drug-related factors :
• Inherent nephrotoxic potential
• Dose
• Duration,
• frequency and form of administration
• Repeated exposure

8. Risk factors
Drug interactions:
Combined or closely associated use of diagnostic
or therapeutic agents with added or
synergistic nephrotoxic potential (e.g.
Radiocontrast agents, aminoglycosides,
NSAIDs, cisplatin,ACEI)

9. Clinical Presentation
General
• The most common manifestation is a decline
in GF leading to a rise in Scr and BUN.
Symptom
• Malaise, anorexia, vomiting, shortness of
breath, or edema.R leading to a rise in Scr and
BUN.

10. Signs
• Decreased urine output may be an early sign
of toxicity, particularly with radiographic
contrast media, NSAIDs, and ACEIs, with
progression to volume overload and
hypertension.

11. Pathogenic mechanism
Most drugs found to cause nephrotoxicity exert
toxic effects by one or more common pathogenic
mechanisms. These include altered
intraglomerular hemodynamics, tubular cell
toxicity, inflammation, crystal nephropathy,
rhabdomyolysis, and thrombotic
microangiopathy.7 Knowledge of offending drugs
and their particular pathogenic mechanisms of
renal injury is critical to recognizing and
preventing drug-induced renal impairment

12. Pathogenic mechanisms
DRUGS CLASS
• Analgesics
Acetaminophen, aspirin
Nonsteroidal anti-
inflammatory drugs
MECHANISMS
Chronic interstitial nephritis
Acute interstitial nephritis,
altered intraglomerular
hemodynamics, chronic
interstitial nephritis,
glomerulonephritis.

13. Antidepressants/mood
stabilizers
Amitriptyline ,doxepin,
fluoxetine .
Lithium
Rhabdomyolysis
Chronic interstitial nephritis,
glomerulonephritis,
rhabdomyolysis

14. Antihistamines:
Diphenhydramine , doxylamine
Antimicrobials:
Acyclovir
Aminoglycosides
Amphotericin B
Rhabdomyolysis
Acute interstitial nephritis,
crystal nephropathy.
Tubular cell toxicity.
Tubular cell toxicity

15. Cardiovascular agents
Angiotensin-converting
enzyme inhibitors,
angiotensin receptor
blockers
Clopidogrel
Statins
Altered intraglomerular
hemodynamics.
Thrombotic microangiopathy.
Rhabdomyolysis.

16. Drugs of abuse
Cocaine, heroin, ketamine,
methadone,
methamphetamine
Proton pump inhibitors
Lansoprazole, omeprazole,
pantoprazole
Rhabdomyolysis.
Acute interstitial nephritis

17. TUBULAR CELL TOXICITY
Renal tubular cells, in particular proximal tubule cells, are
vulnerable to the toxic effects of drugs because their role
in concentrating and reabsorbing glomerular filtrate
exposes them to high levels of circulating toxins.
Drugs that cause tubular cell toxicity do so by impairing
mitochondrial function, interfering with tubular
transport, increasing oxidative stress, or forming free
radicals.
Drugs associated with this pathogenic mechanism of injury
include aminoglycosides, amphotericin B, antiretrovirals
etc

18. Rhabdomyolysis
Rhabdomyolysis is a syndrome in which
skeletal muscle injury leads to lysis of the
myocyte, releasing intracellular contents
including myoglobin and creatine kinase into
the plasma. Myoglobin induces renal injury
secondary to direct toxicity, tubular
obstruction, and alterations in GFR

19. Drugs may induce rhabdomyolysis directly
secondary to a toxic effect on myocyte function,
or indirectly by predisposing the myocyte to
injury. Clinical manifestations of rhabdomyolysis
include weakness, myalgia, and tea-colored urine.
Statins are the most recognizable agents associated
with rhabdomyolysis.
Also cocaine, heroin, ketamine, methadone, and
methamphetamine, have been reported to cause
rhabdomyolysiS

20. General Measures to Prevent Drug-
Induced Nephrotoxicity
• Adjust medication dosages using the Cockcroft-Gault
formula (in adults) or Schwartz formula (in children).
• Avoid nephrotoxic combination.
• Correct risk factors for nephrotoxicity before
initiation of drug therapy.
• Ensure adequate hydration before and during
therapy with potential nephrotoxins.
• Use equally effective non-nephrotoxic drugs
whenever possible.

21. References:
• https://www.aafp.org.com
• Hand book of clinical pharmacy