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What is the mechanism of tachyphylaxis?
Several different mechanisms have been suggested to explain tachyphylaxis, increased destruction of agonist, exhaustion of a transmitter, changes in binding (increase) of agonist to its receptor, and receptor saturation.
What is tachyphylaxis drug tolerance?
Tolerance is the requirement of higher doses of a drug to produce a given response. When this develops rapidly (with only a few administrations of the drug) this is termed tachyphylaxis.
Which drug causes tachyphylaxis?
Over-the-counter ophthalmic decongestant drops, such as Visine (Pfizer), are another category of drugs that induce tachyphylaxis. In particular, these medications contain alpha-adrenergic amines—such as tetrahydrozoline, naphazoline or phenylephrine—that act as vasoconstrictors.
Is tachyphylaxis the same as desensitization?
The term tachyphylaxis is used to describe desensitization that occurs very rapidly, sometimes with the initial dose. The term tolerance is conventionally used to describe a more gradual loss of response to a drug that occurs over days or weeks.
Can tachyphylaxis be reversed?
Intervention and reversal The mechanism may specifically include receptor internalisation and resistance to endogenous vasoconstrictors causing worsening in symptoms post use of medication. Oxymetazoline-induced tachyphylaxis and rebound congestion are reversed by intranasal fluticasone.
What do you mean by tachyphylaxis?
Tachyphylaxis is the continued or repeated exposure to a drug that may lead to a weakened pharmacological response. This presumed to be a consequence of diminished receptor sensitivity in response to consistent stimulation by a drug agonist, which produces a diminished pharmacological response in consequence.
What causes tolerance?
Usually, tolerance develops because metabolism of the drug speeds up (often because the liver enzymes involved in metabolizing drugs become more active) and because the number of sites (cell receptors) that the drug attaches to or the strength of the bond (affinity) between the receptor and drug decreases (see …
Can you reverse tachyphylaxis?
Why does ephedrine cause tachyphylaxis?
When given in repeated doses, tachyphylaxis occurs, probably because of depleted norepinephrine stores. Ephedrine causes an increase in systolic, diastolic, and MAPs. It increases myocardial contractility, heart rate, and cardiac output (see Table 25.1).
What happens if you skip one day of Prozac?
Missing doses of fluoxetine may increase your risk for relapse in your symptoms. Stopping fluoxetine abruptly may result in one or more of the following withdrawal symptoms: irritability, nausea, dizziness, vomiting, nightmares, headache, and/or paresthesias (prickling, tingling sensation on the skin).
How can you prevent drug tolerance?
How can you prevent growing a tolerance?
- Consider non-pharmaceutical treatments. Medication is vital for many patients, but it’s not the only treatment available.
- Keep a journal. Especially when recovering from an injury, it can be hard to recall how you’ve progressed.
- Dispose of unnecessary prescriptions.
What is tachyphylaxis give an example?
Tachyphylaxis appears to be an idiosyncratic process. For example, repeated administration of tyramine, which is a protein precursor to norepinephrine, tends to produce tachyphylaxis. Repeated administration of norepinephrine does not, and reverses tachyphylaxis to tyramine for reasons unknown.