Mnemonic Monday: Sweating Gatorade…or is he on Rifampin?

By Molly Lewis

Rifampin (RIF)– an older antibiotic still used as part of the medical management of tuberculosis, osteomyelitis, meningitis carriers, etc. It is rarely used alone, but is helpful in drug combinations.
It is bactericidal, and acts by inhibiting RNA polymerase (see specifics below).

Unfortunately, Rifampin has potential side effects (what drug doesn’t?).

Here’s a mnemonic to help you remember some of the key testable facts about rifampin:

The R’s of Rifampin:

• RNA polymerase inhibitor
• Revs up Microsomal P450
• Red/Orange body fluids 
• Rapid Resistance if used alone
• Reaches intracellularly, and into abscesses + cavitations, and across the blood-brain barrier (BBB)
• Renal problems- interstitial nephritis

Details, if you’re curious:

• RNA polymerase inhibitor:
  • IF blocks the DNA dependent RNA polymerase, blocking RNA synthesis
• Revs up microsomal P450’s:
  • Increases the rate at which P450 enzymes metabolize drugs, making those drugs less effective / requiring higher drug doses
  • If the patient is taking warfarin, their INR will drop, and they’ll be at risk for clots
  • If they’re taking birth control pills, they will be at risk of getting pregnant!
• Red/orange body fluids
  • RIF is quite red, so patient’s urine, sweat, tears, saliva, etc, can turn red/orange
  • Just think of the MJ picture, and you’ll never forget this!
  • Warn them ahead of time, so they aren’t worried, but reassure them it’s completely harmless!
• Rapid Resistance used alone
  • Bacteria can develop mutations in their RNA polymerase enzyme that block RIF from working, so it’s often used in drug combinations for TB or osteomyelitis
    • RIPE for TB
      • RIF
      • Isoniazid
      • Pyrazinamide
      • Ethambutol
• Reaches intracellularly, and into abscesses + cavitations, and across the blood-brain barrier (BBB)
  • = Increased efficacy
• Renal problems – interstitial nephritis
  • Also watch out for RIF-induced liver problems / hepatotoxicity!

 

Bibliography

• http://www.rxpgonline.com/medicalmnemonic91690.html
• plus some of my own additions!
• (and the idea was stolen from a med school friend – thanks, B!)