Pyrazinamide diffuses into active M. tuberculosis that express pyrazinamidase enzyme that converts pyrazinamide to the active form pyrazinoic acid.



Pharmacology.

Target Actions Organism
AFatty acid synthetase inhibitor Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv)

Also What is the function of pyrazinamide?

Pyrazinamide kills or stops the growth of certain bacteria that cause tuberculosis (TB). It is used with other drugs to treat tuberculosis.

Subsequently, How does pyrazinamide work against TB? How it works: Pyrazinamide is a chemically synthesised bacteriocidal antibiotic. It converts a special enzyme to an active form which inhibits the synthesis of fatty acids; this disrupts the cell membrane and disables energy production which is necessary for the survival of the TB bacteria.

Why is pyrazinamide and isoniazid used together? Rifampin, isoniazid, and pyrazinamide combination is used to treat tuberculosis (TB) infection. It may be taken alone or with one or more other medicines for TB. Rifampin belongs to the class of medicines called antibiotics and works to kill or prevent the growth of bacteria.

Why does pyrazinamide cause hyperuricemia?

Pyrazinamide is a strong urate retention agent, causing a greater than 80% reduction in renal clearance of uric acid at a 300-mg therapeutic daily dose. The metabolite pyrazinoic acid is oxidized by xanthine oxidase and is likely responsible for the hyperuricemic effect.

What is mechanism of action of pyrazinamide?

Mechanism of action. Pyrazinamide is a prodrug that stops the growth of M. tuberculosis. Pyrazinamide diffuses into the granuloma of M. tuberculosis, where the tuberculosis enzyme pyrazinamidase converts pyrazinamide to the active form pyrazinoic acid.

What is the MOA of pyrazinamide?

Mechanism of action. Pyrazinamide is a prodrug that stops the growth of M. tuberculosis. Pyrazinamide diffuses into the granuloma of M.

What is the mechanism of action of ethambutol?

Mechanism of action

Ethambutol is bacteriostatic against actively growing TB bacilli. It works by obstructing the formation of cell wall. Mycolic acids attach to the 5′-hydroxyl groups of D-arabinose residues of arabinogalactan and form mycolyl-arabinogalactan-peptidoglycan complex in the cell wall.

What is the mechanism of action of isoniazid?

Mechanism of action — The antimicrobial activity of INH is selective for mycobacteria, likely due to its ability to inhibit mycolic acid synthesis, which interferes with cell wall synthesis, thereby producing a bactericidal effect [1].

Why is multiple drugs used to treat TB?

When two or more drugs to which in vitro susceptibility has been demonstrated are given together, each helps prevent the emergence of tubercle bacilli resistant to the others. The standard of care for initiating treatment of TB disease is four-drug therapy.

How do you take rifampicin isoniazid pyrazinamide?

Isoniazid, pyrazinamide, and rifampin dosing information

-The dose should be taken with a full glass of water 1 hour before or 2 hours after a meal. -After 2 months of using this drug combination, treatment should be continued with rifampin and isoniazid for at least 4 months.

Is pyrazinamide contraindicated in gout?

Pyrazinamide is contraindicated in patients with a history of gout, severe hepatic impairment, or hypersensitivity to pyrazinamide or related compounds Physician’s Desk Reference (2002).

Does TB medicine increase uric acid?

While receiving anti-TB treatment, an increase in uric acid levels of more than 8 mg/dl was accepted as “hyperuricemia” that is a well-known side effect of PZA. Patients with hyperuricemia and/or arthralgia related to therapy were analyzed for renal disease, concomitant use of loop-inhibiting diuretics.

What is the side effect of pyrazinamide?

Nausea, vomiting, loss of appetite, or mild muscle/joint pain may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly. Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects.

What is the action of ethambutol?

Ethambutol diffuses into Mycobacterium cells. Once inside the cell, ethambutol inhibits the arabinosyltransferases (embA, embB, and embC), preventing formation of the cell wall components arabinogalactan and lipoarabinomannan, and preventing cell division.

Why is pyrazinamide active at low pH?

In a widely accepted model proposed by Zhang and Mitchison (4), low pH causes the protonation of extracellular pyrazinoic acid (POA; the enzymatically activated form of PZA) required for POA to reenter mycobacteria and exert its antimicrobial effect.

Why is pyrazinamide not used in continuation phase?

Because pyrazinamide would often be given in the initial phase unless the patient is at risk of hepatitis, it would be more difficult to identify comparable control subjects in the initial phase than it would be in the continuation phase.

What disease is isoniazid and ethambutol used to treat?

Of the approved drugs, the first-line anti-TB agents that form the core of treatment regimens are: isoniazid (INH) rifampin (RIF) ethambutol (EMB)

What is the mechanism of action of streptomycin?

Streptomycin irreversibly binds to the 16S rRNA and S12 protein within the bacterial 30S ribosomal subunit. As a result, this agent interferes with the assembly of initiation complex between mRNA and the bacterial ribosome, thereby inhibiting the initiation of protein synthesis.

Is pyrazinamide bacteriostatic?

PZA is generally considered to be a bacteriostatic agent. PZA is thought to be more active at an acidic pH (eg, within macrophages) and against dormant or semidormant microorganisms, although the role of PZA against intracellular organisms remains uncertain [6].

Is pyrazinamide bactericidal?

Pyrazinamide is bactericidal for M. tuberculosis when organisms are located in an acid environment such as the macrophage. Pyrazinamide exerts maximum effect during the early phase (2 months) of therapy.

Is ethambutol an inducer or inhibitor?

As measured by liquid chromatography-electrospray ionization tandem mass spectrometry, ethambutol exhibited strong inhibitory potential against CYP1A2 and CYP2E1, moderate against CYP2C19 and CYP2D6 and weak against CYP2A6, CYP2C9 and CYP3A4, based on the IC50 values.

What is the purpose in ethambutol?

Ethambutol eliminates certain bacteria that cause tuberculosis (TB). It is used with other medicines to treat tuberculosis and to prevent you from giving the infection to others. This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.

What are the main side effects of ethambutol?

Headache, loss of appetite, upset stomach, or nausea/vomiting may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly. Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects.