What is tachyphylaxis with 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.

What causes tachyphylaxis?

Tachyphylaxis tends to develop quickly over a short period. It occurs when a person’s response to repeated doses of a medication rapidly decreases over a short period. The condition is also known as acute drug desensitization and can occur with any drug.

What drugs cause 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.

What is the difference between tolerance and tachyphylaxis?

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.

How is tachyphylaxis treated?

TREATMENT STRATEGIES FOR ADT TACHYPHYLAXIS

1. Increasing the current antidepressant dose.
2. Drug holidays or decreasing the current antidepressant dose.
3. Changing antidepressant drugs (to the same mechanism or a different mechanism of action).
4. Augmentation strategies for ADT tachyphylaxis.

What do you mean by Plateau principle in pharmacokinetics?

The plateau principle is a mathematical model or scientific law originally developed to explain the time course of drug action (pharmacokinetics). It applies whenever a drug or nutrient is infused or ingested at a relatively constant rate and when a constant fraction is eliminated during each time interval.

Can you reverse tachyphylaxis?

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 does ephedrine do to your brain?

It activates pathways in the human brain that are responsible for weight loss, but it also activates pathways that could lead to dramatic change in heart rate or blood pressure. Moreover, ephedrine, like nicotine, produces a “high” and can be addictive.

Can tachyphylaxis be reversed?

Intervention and reversal Oxymetazoline-induced tachyphylaxis and rebound congestion are reversed by intranasal fluticasone.

What is antidepressant treatment tachyphylaxis?

Antidepressant tachyphylaxis describes a condition in which a depressed patient loses a previously effective antidepressant treatment response despite staying on the same drug and dosage for maintenance treatment.

Can antidepressants plateau?

However, in some people, a particular antidepressant may simply stop working over time. Doctors don’t fully understand what causes the so-called “poop-out” effect or antidepressant tolerance — known as tachyphylaxis — or why it occurs in some people and not in others.

What does tachyphylaxis stand for?

Tachyphylaxis. From Wikipedia, the free encyclopedia. Jump to navigation Jump to search. Tachyphylaxis ( Greek ταχύς, tachys, “rapid”, and φύλαξις, phylaxis, “protection”) is a medical term describing an acute, sudden decrease in response to a drug after its administration; i.e. a rapid and short-term onset of drug tolerance.

Can tachyphylaxis occur after a small dose of medication?

It can occur after an initial dose or after a series of small doses. Increasing the dose of the drug may be able to restore the original response. Tachyphylaxis is characterized by the rate sensitivity: the response of the system depends on the rate with which a stimulus is presented.

What is the difference between tachyphylaxis and tolerance?

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. There is no clear distinction but the different scales imply that different mechanisms may be involved.

How do you restore tachyphylaxis?

It may be possible to restore the response by increasing the dose (or concentration) of the drug but, in some cases, the tissues may become completely refractory to its effect. The term tachyphylaxis is used to describe desensitization that occurs very rapidly, sometimes with the initial dose.