Chapter 15 Tragedy of Tachyphylaxis
Tachyphylaxis is a medical term describing the decrease in the response to a drug after repeated doses.
This phenomenon is depicted by the graph below.
Tachyphylaxis is a medical term describing the decrease in the response to a drug after repeated doses.
This phenomenon is depicted by the graph below.
On the contrary, resistance just means there is a poor response to a drug.
This phenomenon is depicted by the graph below.
This phenomenon is depicted by the graph below.
A poor response due to superantigens produced by Staphylococcus aureus mentioned in the previous chapter is considered ‘resistance’ as it does not result from repetitive applications of topical steroids.
Tolerance resembles tachyphilaxis in meaning, but this is a phenomenon where increasing the amount of a drug is required to gain the same effect.
This phenomenon is depicted by the graph below.
Tolerance resembles tachyphilaxis in meaning, but this is a phenomenon where increasing the amount of a drug is required to gain the same effect.
This phenomenon is depicted by the graph below.
I understand the difference between tachyphlaxis and tolerance as follows: tachyphylaxis is the result of frequent doses over a short period of time and tolerance is the result of chronic administration over a long period.
It can be predicted from the word origin. ‘Tachy-‘ means very fast as is used for tachycardia, ‘-phylaxis’ means defense, and the word is composed of these, tachyphlaxis, which means rapid decrease in the response to a drug after repeated doses (over a short period).
A typical example of tachyphyalaxis is epinephrine’s action on vessels (blood pressure). Repetitive stimulus over a short time causes the depletion of a vasoconstricting substance, which results in the attenuation of response. Tolerance can occur with morphine or an alcoholic beverage.
Addiction can be depicted as follows.
It can be predicted from the word origin. ‘Tachy-‘ means very fast as is used for tachycardia, ‘-phylaxis’ means defense, and the word is composed of these, tachyphlaxis, which means rapid decrease in the response to a drug after repeated doses (over a short period).
A typical example of tachyphyalaxis is epinephrine’s action on vessels (blood pressure). Repetitive stimulus over a short time causes the depletion of a vasoconstricting substance, which results in the attenuation of response. Tolerance can occur with morphine or an alcoholic beverage.
Addiction can be depicted as follows.
During administration no adverse effect is observed, but discontinuation triggers adverse effect, which is called rebound. Tolerance and addiction can occur simultaneously (as is the case with morphine or an alcoholic beverage). But one can fall into addiction without developing tolerance.
Topical corticosteroids also have an adverse effect of tachyphylaxis, which is capillary constriction. Dr.Vivier’s study is famous.
Tachyphylaxis to the Action of Topically Applied Corticosteroids
By Anthony du Vivier, Richard B. Stoughton published in the Arch Dermatol. 1975; 111 (5):581-583.
Topical corticosteroids also have an adverse effect of tachyphylaxis, which is capillary constriction. Dr.Vivier’s study is famous.
Tachyphylaxis to the Action of Topically Applied Corticosteroids
By Anthony du Vivier, Richard B. Stoughton published in the Arch Dermatol. 1975; 111 (5):581-583.
Horizontal and vertical axes respectively represent time and vasoconstriction (visually observed whiteness of the skin is numerically rated). The ‘↑’ mark indicates topical steroid application. The graph shows tachyphylaxis to vasoconstrictor effects over 4 days of application. The effect recovers after some “drug holidays”.
Though the tachyphylaxis is often referred to in describing the side effects of prolonged use of topical steroids, my opinion is that this phenomenon has little relation with steroid addiction or rebound. Tachyphylaxis indicates the declining response over a short period of administration. (Duration of experiment by Dr. Vivier is only 4 days.)
But he writes in Discussion as follows.
----- Excerpt -----
Patients frequently observe that they become resistant to a topically applied steroid after constant usage. Although there has never been any scientific evidence for this observation, it certainly could be explained in terms of tachyphylaxis.
----- End of excerpt -----
Due to the above phrase, tachyphylaxis has been often referred to in speaking of steroid addiction or rebound in the following way: “Dr. Vivier implicated tachyphylaxis as the possible mechanism of addiction in 1975.” It is certain that using an exotic word makes us feel like talking with some scientific terminology. As a result, the word ‘tachyphyalaxis’began to have wings.
Then those who know what tachyphylaxis really is become reluctant to admit the phenomenon of addiction or rebound saying, “Tachyphylaxis cannot be an explanation for addiction and rebound. Who can believe in such an illogical person?”
No one can encounter the adverse effect of addiction without tracking the progression after discontinuation of a drug.
I call this situation ‘tragedy of tachyphylaxis.’I guess Dr. Vivier et al. only wanted to alert doctors to steroid resistance(or addiction)that they had clinically observed.
But the word ‘tachyphylaxis’ began to be used in a way against his intention.
Tachyphylaxis to topical corticosteroids: the more you use them, the less they work?
Published in the Clinics in Dermatology (2006) 24, 229–230
Look at the initial part of this paper.
----- Excerpt -----
The long-term management of common chronic skin conditions can be frustrating for both patients and physicians. Topical therapies are generally safe and very effective; however, with long-term use, tachyphylaxis may occur.
----- End of excerpt -----
Tachyphylaxis, which is truely a phenomenon observed in short-term application, is used in the above context. This pharmacological terminology has changed into slang in association with long-term treatment with topical corticosteroids.
The author concluded that the discontinuation of topical medications over time may be the best explanation for most “tachyphylaxis” that we see in clinical practice. This is too far from the original meaning.
Dr. Vivier deserves to be called an excellent clinical observer because he discovered tachyphylaxis as an adverse effect of topical steroids and alerted other doctors to the risk of resistance (or addiction). However it was not a good idea handling these two phenomena in combination. Wasn’t it avoidable in construing clinical observation like resistance or addiction under the research techniques available in 1975?
It is meaningful to record various clinically observed phenomena, but we may as well avoid making a conclusion for what cannot be explained with currently available scientific knowledge.
Though the tachyphylaxis is often referred to in describing the side effects of prolonged use of topical steroids, my opinion is that this phenomenon has little relation with steroid addiction or rebound. Tachyphylaxis indicates the declining response over a short period of administration. (Duration of experiment by Dr. Vivier is only 4 days.)
But he writes in Discussion as follows.
----- Excerpt -----
Patients frequently observe that they become resistant to a topically applied steroid after constant usage. Although there has never been any scientific evidence for this observation, it certainly could be explained in terms of tachyphylaxis.
----- End of excerpt -----
Due to the above phrase, tachyphylaxis has been often referred to in speaking of steroid addiction or rebound in the following way: “Dr. Vivier implicated tachyphylaxis as the possible mechanism of addiction in 1975.” It is certain that using an exotic word makes us feel like talking with some scientific terminology. As a result, the word ‘tachyphyalaxis’began to have wings.
Then those who know what tachyphylaxis really is become reluctant to admit the phenomenon of addiction or rebound saying, “Tachyphylaxis cannot be an explanation for addiction and rebound. Who can believe in such an illogical person?”
No one can encounter the adverse effect of addiction without tracking the progression after discontinuation of a drug.
I call this situation ‘tragedy of tachyphylaxis.’I guess Dr. Vivier et al. only wanted to alert doctors to steroid resistance(or addiction)that they had clinically observed.
But the word ‘tachyphylaxis’ began to be used in a way against his intention.
Tachyphylaxis to topical corticosteroids: the more you use them, the less they work?
Published in the Clinics in Dermatology (2006) 24, 229–230
Look at the initial part of this paper.
----- Excerpt -----
The long-term management of common chronic skin conditions can be frustrating for both patients and physicians. Topical therapies are generally safe and very effective; however, with long-term use, tachyphylaxis may occur.
----- End of excerpt -----
Tachyphylaxis, which is truely a phenomenon observed in short-term application, is used in the above context. This pharmacological terminology has changed into slang in association with long-term treatment with topical corticosteroids.
The author concluded that the discontinuation of topical medications over time may be the best explanation for most “tachyphylaxis” that we see in clinical practice. This is too far from the original meaning.
Dr. Vivier deserves to be called an excellent clinical observer because he discovered tachyphylaxis as an adverse effect of topical steroids and alerted other doctors to the risk of resistance (or addiction). However it was not a good idea handling these two phenomena in combination. Wasn’t it avoidable in construing clinical observation like resistance or addiction under the research techniques available in 1975?
It is meaningful to record various clinically observed phenomena, but we may as well avoid making a conclusion for what cannot be explained with currently available scientific knowledge.