Trecator SC

Trecator SC (ethionamide) is a second-line antimycobacterial agent specifically formulated for the treatment of active tuberculosis when first-line therapies have failed or cannot be tolerated. This bacteriostatic medication works by inhibiting mycolic acid synthesis, disrupting the cell wall integrity of Mycobacterium tuberculosis. It is typically administered as part of a combination regimen to prevent resistance development and is reserved for multidrug-resistant (MDR-TB) or extensively drug-resistant (XDR-TB) cases under strict clinical supervision. Proper adherence and monitoring are essential for therapeutic success and minimizing adverse effects.

Features

• Contains 250 mg ethionamide per scored tablet
• Bacteriostatic action against Mycobacterium tuberculosis
• Inhibits mycolic acid synthesis in bacterial cell walls
• Oral administration with bioavailability of approximately 80%
• Metabolized primarily in the liver
• Excreted mainly through urine as metabolites

Benefits

• Provides effective treatment option when first-line tuberculosis drugs fail
• Helps combat multidrug-resistant and extensively drug-resistant TB strains
• Works synergistically with other second-line antituberculosis agents
• Oral formulation allows for outpatient treatment in appropriate cases
• Contributes to reduced transmission of drug-resistant tuberculosis
• Supports WHO-recommended treatment protocols for complex TB cases

Common use

Trecator SC is indicated for the treatment of active pulmonary and extrapulmonary tuberculosis when primary therapeutic agents (isoniazid, rifampin) cannot be used due to resistance or intolerance. It is always administered as part of a combination regimen, typically including at least three other drugs to which the mycobacterial strain is susceptible. Common companion drugs include fluoroquinolones, aminoglycosides, cycloserine, and para-aminosalicylic acid. Treatment duration typically ranges from 18 to 24 months for MDR-TB cases, depending on treatment response and drug susceptibility testing results.

Dosage and direction

The recommended adult dosage is 15-20 mg/kg/day, not to exceed 1 gram daily, typically divided into 2-4 doses. Treatment initiation usually begins with 250 mg once daily, gradually increasing to the target dose over 3-7 days to improve gastrointestinal tolerance. Doses should be taken with food to minimize gastric irritation. Pediatric dosing is 15-20 mg/kg/day in divided doses, with careful monitoring for adverse effects. Dosage adjustments are necessary in patients with hepatic impairment. Regular therapeutic drug monitoring is recommended to ensure adequate serum concentrations while minimizing toxicity.

Precautions

Hepatic function should be assessed before initiation and monitored monthly during therapy due to potential hepatotoxicity. Patients should be advised to avoid alcohol consumption as it may increase the risk of liver damage. Regular ophthalmologic examinations are recommended as ethionamide may cause optic neuritis. Diabetic patients require careful glucose monitoring as the medication may cause hypoglycemia. Thyroid function should be monitored as ethionamide may cause goiter and hypothyroidism. Pregnancy category C: use only if potential benefit justifies potential risk to fetus.

Contraindications

Trecator SC is contraindicated in patients with severe hepatic impairment or active hepatitis. It should not be used in patients with known hypersensitivity to ethionamide or any component of the formulation. Contraindicated in patients with severe psychiatric disorders due to potential neuropsychiatric side effects. Not recommended for prophylactic treatment of tuberculosis or for infections caused by non-tuberculous mycobacteria unless susceptibility is confirmed.

Possible side effects

Gastrointestinal: Nausea (30-50%), vomiting (10-20%), abdominal pain, metallic taste, excessive salivation, anorexia, weight loss Hepatic: Elevated transaminases (15-30%), hepatitis (2-5%), jaundice Neurological: Peripheral neuropathy (10-15%), dizziness, headache, tremors, depression, anxiety, psychosis Endocrine: Hypothyroidism, gynecomastia, menstrual irregularities, hypoglycemia Dermatological: Rash, photosensitivity, acne Ophthalmic: Optic neuritis, blurred vision Other: Orthostatic hypotension, arthralgia, impotence

Drug interaction

Cycloserine: Increased risk of neurotoxicity and CNS effects Isoniazid: Increased risk of hepatotoxicity and neurotoxicity Rifampin: May decrease ethionamide concentrations Oral hypoglycemics: Enhanced hypoglycemic effect Thyroid hormone replacements: May require dosage adjustment Vitamin B6 (pyridoxine): Concomitant administration recommended to reduce neurotoxicity Alcohol: Increased risk of hepatotoxicity and CNS depression

Missed dose

If a dose is missed, it should be taken as soon as remembered unless it is nearly time for the next scheduled dose. In that case, skip the missed dose and resume the regular dosing schedule. Do not double the dose to make up for a missed one. Consistent adherence is critical for treatment success and preventing resistance development. Patients should maintain a dosing diary and use pill organizers to improve compliance.

Overdose

Symptoms may include severe nausea, vomiting, dizziness, hypotension, and neuropsychiatric disturbances. There is no specific antidote for ethionamide overdose. Management includes gastric lavage if presented early, activated charcoal, and supportive care with monitoring of vital signs. Hemodialysis is not effective due to high protein binding. Symptomatic treatment for specific manifestations should be provided. Contact poison control center immediately for guidance.

Storage

Store at controlled room temperature (20-25°C or 68-77°F) in a dry place protected from light and moisture. Keep in the original container with the lid tightly closed. Do not store in bathroom or kitchen where humidity levels may fluctuate. Keep out of reach of children and pets. Do not use beyond the expiration date printed on the packaging. Properly dispose of any unused medication through take-back programs.

Disclaimer

This information is for educational purposes only and does not constitute medical advice. Treatment decisions must be made by qualified healthcare professionals based on individual patient circumstances. Dosage and administration should be determined by a physician familiar with the patient’s medical history and current condition. Always follow the prescribing information provided with the medication and consult healthcare providers for personalized medical advice.

Reviews

“Trecator SC has been invaluable in our MDR-TB treatment program. While gastrointestinal side effects are challenging, dose escalation and antiemetics help manage these issues effectively.” - Dr. Elena Rodriguez, Infectious Disease Specialist

“Despite its side effect profile, ethionamide remains a crucial component of our drug-resistant TB regimens. The key is careful patient selection and proactive management of adverse effects.” - TB Clinical Pharmacist

“Patient education is essential with Trecator SC. Those who understand the importance of adherence despite side effects have significantly better outcomes in our clinic.” - TB Nurse Coordinator