1. Dismiss Notice
  2. Download free Tapatalk for iPhone or Tapatalk for Android for your phone and follow the SDN forums with push notifications.
    Dismiss Notice

drug interactions

Discussion in 'Pharmacy' started by museabuse, May 11, 2008.

  1. museabuse

    museabuse Senior Member
    7+ Year Member

    Joined:
    Apr 27, 2005
    Messages:
    604
    Likes Received:
    6
    Status:
    Pharmacy Student
    Just curious,

    What are some common drug interactions that you always call the Dr?
     
  2. Note: SDN Members do not see this ad.

  3. FruitFly

    Moderator Emeritus 5+ Year Member

    Joined:
    Apr 20, 2007
    Messages:
    3,590
    Likes Received:
    5
    Not that I'm pushing this book, but "Top 100 Drug Interactions" by Hansten and Horn, is a good one to take a look at. It has a lot of useful information. (I know there's a 2007 Edition out there)

    http://www.amazon.com/Top-100-Drug-Interactions-Management/dp/0967471877
     
  4. RxWildcat

    RxWildcat Julius Randle BEASTMODE!
    Moderator Emeritus 5+ Year Member

    Joined:
    Mar 25, 2008
    Messages:
    1,406
    Likes Received:
    2
    Status:
    Pharmacist
    I've been calling to change a lot of photosensitizing antibiotics lately. I'd say it varies a lot for the most part.

    edit: oops, I guess you wanted drug-drug interactions, my bad.
     
  5. npage148

    npage148 Senior Member
    PhD Pharmacist 10+ Year Member

    Joined:
    May 2, 2005
    Messages:
    2,024
    Likes Received:
    737
    Status:
    Pharmacist
    bactrim and warfarin

    I also love calling dentists to tell them they gave a lortab script to a pt on MSIR and Mscontin. It happens alot and they are always more than happy to cancel it
     
  6. BMBiology

    BMBiology temporarily banned~!
    15+ Year Member

    Joined:
    Feb 26, 2003
    Messages:
    6,819
    Likes Received:
    2,255
    I agree with your action but I dont want people to think there is a dangerous drug-drug interaction between lortab and morphine per say. There may be an additive effect when two opiods are prescribed. It is fine if the prescriber wants to change or not add another opioid and caution should be used when an opioid is prescribed but there is no max dose for opioids, unless it also contains another ingredient such as APAP. Just remember that many patients need more than one opioid to control their pain.
     
  7. njac

    njac Senior Member
    10+ Year Member

    Joined:
    Mar 20, 2005
    Messages:
    11,585
    Likes Received:
    5,958
    Status:
    Pharmacist
    We were taught that >1 opiate is not any more efficacious for pain control than only 1, and to increase the dose of the existing drug and make sure they're using rescue doses when needed.
     
  8. BMBiology

    BMBiology temporarily banned~!
    15+ Year Member

    Joined:
    Feb 26, 2003
    Messages:
    6,819
    Likes Received:
    2,255
    That is true. Some patients need a long acting opioid for maintenance and a fast acting opioid for acute pain. However, it really varies among patients. There's no one rule for every patients.

    For example, a patient may do well on methadone but when dose >200 mg/day, the risk for QT prolongation significantly increases. So for this patient, it may better to prescribe another opioid than to increase the methadone dose above 200mg/day.

    It's not a matter of drug drug interaction. It is a matter of risk vs. benefits.
     
  9. Pharmavixen

    Pharmavixen foxy pharmacist
    7+ Year Member

    Joined:
    Jan 20, 2008
    Messages:
    1,043
    Likes Received:
    14
    Status:
    Pharmacist
    I think you're partly right; in my experience, polypharmacy is more common than an intelligent use of more than one opioid. However, methadone also is an antagonist at the NMDA receptors and is more effective for neuropathic pain.

    But the prescribing of oxycodone has gone up 400% in the US in the past ten years. Americans are the #1 users of opioids worldwide. Were there that many people in severe intractable pain B4?

    Back O/T: as a methadone dispenser, I'm always phoning drs re: drug interactions. Methadone drs are fairly up on the interactions, but other MDs the pts see may not be. Methadone is a substrate for CP450 3A4, which is huge, so tons of drugs affect it, either raising or lowering its levels.

    Recently I contacted public health about a methadone client started on rifampin. The guidelines where I work suggest methadone patients receive rifabutin instead, but it's not covered by Drug Benefit (like Medicaid), so they kept her on the rifampin, which potentiates the metabolism of the methadone. So...this lady experienced WD symptoms, and has relapsed into street drug use.
     
  10. BMBiology

    BMBiology temporarily banned~!
    15+ Year Member

    Joined:
    Feb 26, 2003
    Messages:
    6,819
    Likes Received:
    2,255
    Pharmavixem: since you are a methadone pharmacist, any recommendation on a good read on methadone?
     
  11. aphistis

    Moderator Emeritus 10+ Year Member

    Joined:
    Feb 15, 2003
    Messages:
    8,392
    Likes Received:
    29
    Status:
    Attending Physician, Dentist
    I'd be glad for the phone call.

    I don't stack narcotics. If I'm writing pain meds for someone who's already on hydrocodone or stronger, they get ibuprofen (if it's OK for them) or else just instructions to keep taking their existing pain meds as scheduled and to call if they're having problems. I've gotten very few phone calls.
     
  12. tussionex

    tussionex Pharmacist
    2+ Year Member

    Joined:
    Jan 23, 2007
    Messages:
    698
    Likes Received:
    4
    Status:
    Pharmacist
    most dentists i know in my area don't prescribe more than a few days' worth of vicodin, etc, so honestly, if i had a patient that i knew was stabilized on MSContin or the like [like an RA patient that i had....took a boatload of the stuff] i really wouldnt have a problem with letting him/her have the vicodin....OF COURSE, with some counseling and the recommendation that an NSAID would probably help dental pain just as well if not better.

    i don't think a coupla vicodin in an opioid tolerant patient will create that much of an additive effect.

    personally, for all my dental work i've had, root canals, extractions...i've always found that plain old motrin does the trick just fine!
     
  13. npage148

    npage148 Senior Member
    PhD Pharmacist 10+ Year Member

    Joined:
    May 2, 2005
    Messages:
    2,024
    Likes Received:
    737
    Status:
    Pharmacist
    I guess my direction was not the DDI per say, but that the pt is usually a drug seeker going to dentists to get more narcotics.

    If they had legitimate dental pain why would they want/need hydrocodone when they had a stock of MSIR or another strong fast acting opoid
     
  14. BMBiology

    BMBiology temporarily banned~!
    15+ Year Member

    Joined:
    Feb 26, 2003
    Messages:
    6,819
    Likes Received:
    2,255
    Just want to clarify in terms of potency, hydrocodone PO = morphine PO.
     
  15. b*rizzle

    b*rizzle Master of Useless Info
    5+ Year Member

    Joined:
    Nov 25, 2004
    Messages:
    548
    Likes Received:
    1
    Status:
    Pharmacist
    Back on topic: Lipitor and ketoconazole/clarithromycin. We always call to verify & also let the doctor know we've told the patient to stop their Lipitor while on either.
     
  16. Pharmavixen

    Pharmavixen foxy pharmacist
    7+ Year Member

    Joined:
    Jan 20, 2008
    Messages:
    1,043
    Likes Received:
    14
    Status:
    Pharmacist
    I usually recommend the College of Physicians and Surgeons of Ontario clinical practice guidelines, like Methadone for Pain, or Methadone Maintenance as an overview. Though the guidelines are intended for doctors practising in Ontario, there's lots of good general info.
     

Share This Page