P14S06: Drug interaction (Warfarin and Probenecid and
Septra)
Bottom line: Information on drug
interactions (Warfarin and Probenecid and Septra) was used to persuade other health professionals to make
changes (double the dose of Warfarin). It contributed to avoid inappropriate
treatment.
Level 1 outcome (situational relevance): On December 3, 2008, P14 did a search at work, by themselves, after a
phone encounter with a patient. They retrieved two information hits about drug interactions (Warfarin and Probenecid and
Septra). The reported search
objectives were: to address a clinical question, and to exchange information
with other health professional. “[The patient],
[a 53 year old man], was in the hospital, had cellulitis and he
had a clot in his leg. [They] [the doctor] put him on
Warfarin in the hospital […] and his INR [International Normalized Ratio]
was in the right range. And then he came out of the hospital and he was on
antibiotics for a urinary tract infection. And after he finished the antibiotics
the INR fell and remained low and stubborn and wouldn’t move. And we just had
no idea what was going on. […] So the nurse and I were dealing with him on
the phone.” According to P14, the information from e-Therapeutics+ was in agreement
with and less relevant than the information from another electronic resource (Micromedics) since
e-Therapeutics does not contain information re: the onset and resolution of the
drug interaction.
Level 2 outcome (cognitive impact): Two hits were associated with a report of positive cognitive impact (see table). Regarding learning,
P14 stated: “When somebody
goes on antibiotics I usually ask that an INR be done in a week. Given this
man’s history, it solidifies that [the request for an INR] because the
only time he was therapeutic was when he was on antibiotics. So he was having a
drug interaction that made him therapeutic. . […] I [also] learned that Probenecid does not interact
with Warfarin.” Regarding confirmation,
reassurance, and reminder, P14 stated: “[Again], it confirms my request for INRs when people
are started on Septra. […] I’m reassured just because that has always
been my way of practicing…checked if it’s right. […] I did already
know that, I just went back to double-check.”
Retrieved
information hits:
1) e-Therapeutics+ (CIRT): Drug interactions – Keywords: Warfarin – Probenecid – Septra – Analyse – No interaction (P14S06H01)
2) e-Therapeutics+ (CIRT): Drug interactions – Keywords: Septra – Warfarin – Analyse – Discussion section (P14S06H02)
Level 3 outcome
(information use): Information on drug interactions (Warfarin and Probenecid
and Septra) was retrieved, and used to persuade other health professionals to
change (information used as presented in e-Therapeutics+). “We’ve had to double the dose. […] It was hard to understand how somebody could
be in a normal range on a dose and then all of the sudden, for no particular
reason, be sub-therapeutic. […] We had to push the dose up and the nurse was
scared that we were going to make him bleed. And the doctor was scared that he [the patient] was going to
have a clot.”
Level 4 outcome (patient health): Regarding patient
health, P14 reported that the information contributed to avoid inappropriate
treatment. “[What] I wanted to
avoid was an inappropriate increase in the dose or an inappropriately low dose.
[…] I needed to understand what was going on, [so] I could give
advice [to the nurse and the doctor] on which way to go next. [When you think about it now,
did this information have the expected benefits as rated on the questionnaire?]
Yes!”
Levels of outcome of information-seeking
|
Situational relevance |
Positive cognitive
impact |
Information use |
Patient health |
|
Address a clinical question Exchange information |
Learned something Reminded something Confirmed Reassured |
Persuade |
Avoid |