Erythromycin breath test

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Erythromycin breath test
Purposemeasure oxidation and elimination from the system

The erythromycin breath test (ERMBT) is a method used to measure metabolism (oxidation and elimination from the system) by a part of the cytochrome P450 system. [1] Erythromycin produces 14CO2, and this 14CO2 can be measured to study drugs that interact with the cytochrome P450 system. [2] Erythromycin is tagged with carbon-14 and given as an intravenous injection; after 20 minutes the subject blows up a balloon and the carbon dioxide exhaled that is tagged with carbon-14 shows the activity of the CYP3A4 isoenzyme on the erythromycin. ERMBT can be used to determine how drugs that the CYP3A4 isoenzyme metabolizes will function in a given individual.

Erythromycin is a drug that treats bacterial infections like bronchitis, sexually transmitted diseases, and pneumonia. The medication is in a capsule form and takes on a "delayed-release," to ensure it is only broken down once it reaches the intestine and not by stomach acids. [3]

The test allows doctors to determine or predict an individual’s drug treatment outcome. Will a patient develop serious or fatal side effects from a certain drug? Which foods and drugs should not be taken together? With this and other tests a physician may determine treatment outcomes in advance or study the effects of new drugs. [1]

Some patients have a congenital inability to synthesize certain enzymes, so drugs may build up to toxic levels in their system or other drugs and foods a patient is taking may consume all of their ability to metabolize certain foods and drugs. An example is: when a person taking a cholesterol-lowering statin drug then drinking grapefruit juice, they may have a poor treatment outcome (adverse drug reaction) and sustain liver damage or kidney failure due to drug induced rhabdomyolysis (the breaking up of muscle tissue). [4]

Related Research Articles

Erythromycin Chemical compound

Erythromycin is an antibiotic used for the treatment of a number of bacterial infections. This includes respiratory tract infections, skin infections, chlamydia infections, pelvic inflammatory disease, and syphilis. It may also be used during pregnancy to prevent Group B streptococcal infection in the newborn, as well as to improve delayed stomach emptying. It can be given intravenously and by mouth. An eye ointment is routinely recommended after delivery to prevent eye infections in the newborn.

Atorvastatin Cholesterol-lowering medication

Atorvastatin, sold under the brand name Lipitor among others, is a statin medication used to prevent cardiovascular disease in those at high risk and to treat abnormal lipid levels. For the prevention of cardiovascular disease, statins are a first-line treatment. It is taken by mouth.

Lovastatin Chemical compound

Lovastatin, sold under the brand name Mevacor among others, is a statin medication, to treat high blood cholesterol and reduce the risk of cardiovascular disease. Its use is recommended together with lifestyle changes. It is taken by mouth.

Cytochrome P450 Class of enzymes

Cytochromes P450 (CYPs) are a superfamily of enzymes containing heme as a cofactor that functions as monooxygenases. In mammals, these proteins oxidize steroids, fatty acids, and xenobiotics, and are important for the clearance of various compounds, as well as for hormone synthesis and breakdown. In 1963, Estabrook, Cooper, and Rosenthal described the role of CYP as a catalyst in steroid hormone synthesis and drug metabolism. In plants, these proteins are important for the biosynthesis of defensive compounds, fatty acids, and hormones.

Desloratadine Allergy medication

Desloratadine (trade names Clarinex and Aerius) is a tricyclic H1 antagonist that is used to treat allergies. It is an active metabolite of loratadine.

Pharmacogenomics Study of the role of the genome in drug response

Pharmacogenomics is the study of the role of the genome in drug response. Its name reflects its combining of pharmacology and genomics. Pharmacogenomics analyzes how the genetic makeup of an individual affects their response to drugs. It deals with the influence of acquired and inherited genetic variation on drug response in patients by correlating gene expression or single-nucleotide polymorphisms with pharmacokinetics and pharmacodynamics. The term pharmacogenomics is often used interchangeably with pharmacogenetics. Although both terms relate to drug response based on genetic influences, pharmacogenetics focuses on single drug-gene interactions, while pharmacogenomics encompasses a more genome-wide association approach, incorporating genomics and epigenetics while dealing with the effects of multiple genes on drug response.

CYP3A4 Enzyme which breaks down foreign organic molecules

Cytochrome P450 3A4 is an important enzyme in the body, mainly found in the liver and in the intestine. It oxidizes small foreign organic molecules (xenobiotics), such as toxins or drugs, so that they can be removed from the body. It is highly homologous to CYP3A5, another important CYP3A enzyme.

CYP2D6 Human liver enzyme

Cytochrome P450 2D6 (CYP2D6) is an enzyme that in humans is encoded by the CYP2D6 gene. CYP2D6 is primarily expressed in the liver. It is also highly expressed in areas of the central nervous system, including the substantia nigra.


Drug-interaction occurs when a drug's mechanism of action is disturbed by the concomitant administration substances such as foods, beverages or other drugs. The cause is often the inhibition of the specific receptors available to the drug, forcing the drug molecules to bind to other non-intended targets which result in an array of side-effects.

Dextromethorphan Antitussive medication of the dissociative class

Dextromethorphan is a medication most often used as a cough suppressant in over-the-counter cold and cough medicines. It is sold in syrup, tablet, spray, and lozenge forms.

Terfenadine Chemical compound

Terfenadine is an antihistamine formerly used for the treatment of allergic conditions. It was brought to market by Hoechst Marion Roussel and was marketed under various brand names, including Seldane in the United States, Triludan in the United Kingdom, and Teldane in Australia. It was superseded by fexofenadine in the 1990s due to the risk of a particular type of disruption of the electrical rhythms of the heart and has been withdrawn from markets worldwide.

Cilostazol

Cilostazol, sold under the brand name Pletal among others, is a medication used to help the symptoms of intermittent claudication in peripheral vascular disease. If no improvement is seen after 3 months, stopping the medication is reasonable. It may also be used to prevent stroke. It is taken by mouth.

Naringin Chemical compound

Naringin is a flavanone-7-O-glycoside between the flavanone naringenin and the disaccharide neohesperidose. The flavonoid naringin occurs naturally in citrus fruits, especially in grapefruit, where naringin is responsible for the fruit's bitter taste. In commercial grapefruit juice production, the enzyme naringinase can be used to remove the bitterness created by naringin. In humans naringin is metabolized to the aglycone naringenin by naringinase present in the gut.

CYP1A2 Enzyme in the human body

Cytochrome P450 1A2, a member of the cytochrome P450 mixed-function oxidase system, is involved in the metabolism of xenobiotics in the human body. In humans, the CYP1A2 enzyme is encoded by the CYP1A2 gene.

Grapefruit–drug interactions Drug interactions with grapefruit juice

Some fruit juices and fruits can interact with numerous drugs, in many cases causing adverse effects. The effect was first discovered accidentally, when a test of drug interactions with alcohol used grapefruit juice to hide the taste of the ethanol.

CYP2C19

Cytochrome P450 2C19 is an enzyme protein. It is a member of the CYP2C subfamily of the cytochrome P450 mixed-function oxidase system. This subfamily includes enzymes that catalyze metabolism of xenobiotics, including some proton pump inhibitors and antiepileptic drugs. In humans, it is the CYP2C19 gene that encodes the CYP2C19 protein. CYP2C19 is a liver enzyme that acts on at least 10% of drugs in current clinical use, most notably the antiplatelet treatment clopidogrel (Plavix), drugs that treat pain associated with ulcers, such as omeprazole, antiseizure drugs such as mephenytoin, the antimalarial proguanil, and the anxiolytic diazepam.

Pitavastatin Chemical compound

Pitavastatin is a member of the blood cholesterol lowering medication class of statins.

Synergistic enhancers of antiretrovirals usually do not possess any antiretroviral properties alone, but when they are taken concurrently with antiretroviral drugs they enhance the effect of that drug.

AmpliChip CYP450 Test is a clinical test from Roche. The test aims to find the specific gene types of the patient that will determine how he or she metabolizes certain medicines, therefore guides the doctors to prescribe medicine for best effectiveness and least side effects.

Bergamottin Chemical compound

Bergamottin (5-geranoxypsoralen) is a natural furanocoumarin found in the pulp of pomelos and grapefruits. It is also found in the peel and pulp of the bergamot orange, from which it was first isolated and from which its name is derived.

References

  1. 1 2 Zhou S, Chan E, Lim LY, et al. (October 2004). "Therapeutic drugs that behave as mechanism-based inhibitors of cytochrome P450 3A4". Curr. Drug Metab. 5 (5): 415–42. doi:10.2174/1389200043335450. PMID   15544435.
  2. Chhun, Stephanie (2009). "Gefitinib-phenytoin interaction is not correlated with the 14 C-erythromycin breath test in healthy male volunteers". British Journal of Clinical Pharmacology. 68 (2): 226–237. doi:10.1111/j.1365-2125.2009.03438.x. PMC   2767287 . PMID   19694743.
  3. "Erythromycin: MedlinePlus Drug Information". medlineplus.gov. Retrieved 2022-05-08.
  4. Lee, Jonathan W.; Morris, Joan K.; Wald, Nicholas J. (2016-01-01). "Grapefruit Juice and Statins". The American Journal of Medicine. 129 (1): 26–29. doi:10.1016/j.amjmed.2015.07.036. ISSN   0002-9343. PMID   26299317.