Mechanism of action
Pyrazinamide is released into Mycobacterium tuberculosis, while the enzyme pyrazinamidase converts pyrazinamide into the active form of pyrazinoic acid. Under acidic conditions, pyrazinoic acid is slowly released, converting to a protonated conjugate acid that appears to readily enter and accumulate in the bacillus.
The net effect is that more pyrazinoic acid is stored inside the bacillus at a more acidic pH than at a neutral pH. Pyrazinoic acid inhibits the fatty acid synthesizing enzyme (FAS), which is essential for the production of fatty acids in bacteria.
It has also been suggested that the accumulation of pyrazinoic acid disrupts the membrane potential and interferes with the energy production that is necessary for the survival of tuberculosis in the acidic site of infection.
It has been shown that pyrazinoic acid binds to ribosomal protein S1 and inhibits translation. This may explain the drug’s ability to kill latent mycobacteria.
Pyrazinamide is a pyrazine that is used as an anti-tuberculosis drug
Pharmacodynamics
Pyrazinamide drug kills or stops the growth of bacteria that cause tuberculosis.
Pharmacokinetics
– Absorption: well absorbed
– Distribution: widely in body tissues and fluids, including liver, lung and CSF
– Relative diffusion from blood to CSF: sufficient with or without inflammation (above normal MIC)
– Ratio of CSF level: blood: inflamed meninges: 100%
– Binding to protein: 50%
– Metabolism: Hepatic
– Elimination half-life: 9-10 hours
– Time to reach the maximum serum concentration: within 2 hours
– Excretion: urine (4% as unchanged drug)
Uses of pyrazinamide
Tuberculosis, for initial treatment of acute tuberculosis in adults and children along with other anti-tuberculosis drugs
Dosage of pyrazinamide
adults
Tuberculosis treatment for HIV negative
Daily treatment
15-30 mg/kg orally once a day; Do not exceed 2 grams per day
Treatment twice a week
50 mg/kg twice a week; do not exceed 2 g/dose
Tuberculosis treatment for HIV-exposed/infected
20-40 mg/kg/oral dose once a day; Do not exceed 2 grams per day
children
Tuberculosis treatment
– Daily treatment
15-30 mg/kg orally once a day; It should not exceed 2000 mg per day
– Treatment twice a week
50 mg/kg/dose; It should not exceed 3000 mg per day
prohibited usage
Acute gout, liver damage, severe sensitivity
Side effects of pyrazinamide
Nausea, vomiting, muscle pain, anorexia, malaise, joint pain
Drug interactions
Probenecid, Mitiglinide, Isoniazid, Rifampin, Triflunomide, Live Bacillus vaccine, Live cholera vaccine, Lomitapide, Mipomersen, Remdesivir
Recommended tips
Check blood work as directed by your doctor. Talk to the doctor.
– Pyrazinamide drug may affect certain tests. Inform the use of this medicine to all health care workers and laboratory workers.
– If you have high blood sugar (diabetes), you should check your blood sugar regularly.
– Watch out for gout attacks
– Talk to your doctor before consuming alcohol.
– Tell your doctor if you are pregnant or planning to become pregnant. During pregnancy, you should discuss the benefits and risks of using pyrazinamide.
– Tell your doctor if you are breastfeeding. You should discuss any risks to your child.
– Take with or without food.
– Do not miss a dose to get the maximum effect.
– Even if you feel better, continue taking the medicine according to the doctor’s instructions.
– Take a missed dose as soon as you think about it.
– Take the forgotten dose as soon as you remember. If it is close to the next dose, skip it. Do not double or increase the dose.
Use in pregnancy
C (Group C drugs should only be used with a doctor’s prescription. The risks of using this group of drugs have not yet been ruled out, or human studies have not been conducted, and when the doctor feels that the benefits of using this group of drugs outweigh the possible harms. It is much more, and its consumption is necessary for the patient to prescribe.)
Similar drugs
capreomycin, ethambutol, isoniazid, rifampin, clofazimine, rifabutin, rifapentine, ethionamide, cycloserine, aminosalicylic acid, bedaquiline
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