My INR has been going down lately and I can't figure it out.
Then just by chance I found the following article last night, and things began to make sense.
I would like to hear Al's comment on this one.
--------------------------------------------------------------------------------
Menthol Cough Drop Lowers INR
Tuesday, February 1, 2005
A possible case of menthol cough drops significantly
lowering a patient's INR
--------------------------------------------------------------------------------
An interesting case was recently presented in Annals of
Pharmacotherapy published 11 January 2005. A possible
case of menthol cough drops were involved in significantly
lowering a patient's INR.
CASE SUMMARY: A 57-year-old white male awaiting
cardioversion for atrial fibrillation was prescribed warfarin.
His dosage was adjusted to 7 mg daily to provide stable
international normalized ratio (INR) values of 2.28-2.68.
Approximately one week later, his INR fell to 1.45. During a
follow-up interview, the patient reported that he
experienced a flu-like illness during the previous week and
had been using menthol cough drops. No other potential
causes for the decreased INR were found. Illness will most
often elevate the INR; we therefore concluded that the
cough drops were the likely cause of this reaction, and the
warfarin dose was increased to 53 mg/wk. After
discontinuing use of menthol cough drops, the warfarin
dose was returned to the previous amount and the INR
remained stabilized.
Annals of Pharmacotherapy, Jan. 2005
It seemed ironic that the patients flu-like illness at least did
not counter the menthol affect. An INR of 1.45 is
sub-therapeutic for all indications for Coumadin2 (warfarin).
Had the patient taken a menthol cough drop in the absence
of the flu the INR might have dropped further.
Had this patient been a mechanical heart valve patient and
taken repeated doses of menthol cough drops or for a
more extended period of time ? a significant higher risk of
thrombosis might have occurred given the nature of the
valve. The list of interacting foods, medicines and herbals
continues to build ? the strategy to greater control patient
INR's remains constant. For higher risk patients weekly
home testing has proven to increase time in range and
prevent hazardous trends over traditional monthly testing.
This article came from pt/inr.com
Needless to say I threw those lozenges in the trash.
Just never heard of such an interaction before.
Then just by chance I found the following article last night, and things began to make sense.
I would like to hear Al's comment on this one.
--------------------------------------------------------------------------------
Menthol Cough Drop Lowers INR
Tuesday, February 1, 2005
A possible case of menthol cough drops significantly
lowering a patient's INR
--------------------------------------------------------------------------------
An interesting case was recently presented in Annals of
Pharmacotherapy published 11 January 2005. A possible
case of menthol cough drops were involved in significantly
lowering a patient's INR.
CASE SUMMARY: A 57-year-old white male awaiting
cardioversion for atrial fibrillation was prescribed warfarin.
His dosage was adjusted to 7 mg daily to provide stable
international normalized ratio (INR) values of 2.28-2.68.
Approximately one week later, his INR fell to 1.45. During a
follow-up interview, the patient reported that he
experienced a flu-like illness during the previous week and
had been using menthol cough drops. No other potential
causes for the decreased INR were found. Illness will most
often elevate the INR; we therefore concluded that the
cough drops were the likely cause of this reaction, and the
warfarin dose was increased to 53 mg/wk. After
discontinuing use of menthol cough drops, the warfarin
dose was returned to the previous amount and the INR
remained stabilized.
Annals of Pharmacotherapy, Jan. 2005
It seemed ironic that the patients flu-like illness at least did
not counter the menthol affect. An INR of 1.45 is
sub-therapeutic for all indications for Coumadin2 (warfarin).
Had the patient taken a menthol cough drop in the absence
of the flu the INR might have dropped further.
Had this patient been a mechanical heart valve patient and
taken repeated doses of menthol cough drops or for a
more extended period of time ? a significant higher risk of
thrombosis might have occurred given the nature of the
valve. The list of interacting foods, medicines and herbals
continues to build ? the strategy to greater control patient
INR's remains constant. For higher risk patients weekly
home testing has proven to increase time in range and
prevent hazardous trends over traditional monthly testing.
This article came from pt/inr.com
Needless to say I threw those lozenges in the trash.
Just never heard of such an interaction before.
