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 are intolerable. As a nicotinamide derivative, it exhibits bacteriostatic activity against Mycobacterium tuberculosis by inhibiting mycolic acid synthesis, disrupting cell wall integrity. This oral medication is indicated for use in combination regimens under Directly Observed Therapy (DOT) protocols to prevent further resistance development. Its role is critical in managing multidrug-resistant (MDR-TB) and extensively drug-resistant tuberculosis (XDR-TB), serving as a cornerstone in complex therapeutic algorithms where conventional options are exhausted.

Features

• Contains 250 mg ethionamide per scored tablet
• Oral formulation allowing for outpatient management
• Demonstrated in vitro activity against M. tuberculosis including some resistant strains
• Compatible with WHO-recommended MDR-TB treatment protocols
• Requires prescription and specialist supervision
• Manufactured under strict pharmaceutical compliance standards

Benefits

• Provides therapeutic option when first-line TB drugs cannot be used due to resistance or intolerance
• Disrupts mycobacterial cell wall synthesis through targeted mechanism of action
• Enables continuation of treatment in community settings with proper monitoring
• Contributes to reduced transmission of drug-resistant tuberculosis strains
• Supports completion of comprehensive TB eradication regimens
• Helps prevent progression to more extensively drug-resistant disease

Common use

Trecator SC is primarily employed in the management of pulmonary and extrapulmonary tuberculosis caused by organisms resistant to isoniazid or other first-line antitubercular drugs. It is never used as monotherapy but is incorporated into individualized regimens based on drug susceptibility testing results. Typical combinations include pairing with other second-line agents such as fluoroquinolones, injectable aminoglycosides, cycloserine, or para-aminosalicylic acid. Treatment duration typically extends for 18-24 months depending on disease severity, treatment response, and resistance patterns. Its use is governed by specialized TB programs with expertise in managing complex resistance cases.

Dosage and direction

The recommended adult dosage is 15-20 mg/kg/day, typically administered as 250 mg to 500 mg twice daily with meals to minimize gastrointestinal irritation. Dosing should be initiated at lower ranges and gradually increased to the target dose over 3-5 days to improve tolerance. Pediatric dosing is calculated at 15-20 mg/kg/day in divided doses, not to exceed 1 gram daily. Tablets should be swallowed whole with water and taken consistently with food. Dosage adjustments are necessary in hepatic impairment, while no adjustment is typically needed for renal impairment. Treatment must continue for the full prescribed duration even if symptoms improve earlier.

Precautions

Hepatic function should be monitored before initiation and periodically throughout therapy, as ethionamide is associated with hepatotoxicity. Patients should be advised to report symptoms including nausea, vomiting, abdominal pain, dark urine, or jaundice immediately. Psychiatric manifestations including depression, psychosis, and hallucinations require careful monitoring. Peripheral neuropathy is common and may be prevented with pyridoxine (vitamin B6) supplementation. Diabetic patients may experience worsened glucose control. Hypothyroidism has been reported, necessitating thyroid function monitoring. Visual disturbances should prompt ophthalmological evaluation.

Contraindications

Trecator SC is contraindicated in patients with severe hepatic impairment or active hepatitis. History of hypersensitivity to ethionamide or any component of the formulation prohibits use. It should not be administered to patients with severe psychiatric disorders that may be exacerbated by treatment. Concomitant use with drugs that prolong QT interval requires careful risk-benefit assessment. Pregnancy category C warrants avoidance unless potential benefits justify potential fetal risks. Breastfeeding is not recommended during therapy.

Possible side effect

• Gastrointestinal: Nausea (30-50%), vomiting (10-20%), abdominal pain, metallic taste, excessive salivation
• Hepatic: Elevated transaminases (15-30%), hepatitis (2-5%), jaundice
• Neurological: Peripheral neuropathy (10-20%), dizziness, headache, tremors, seizures
• Psychiatric: Depression (5-10%), anxiety, psychosis, emotional instability
• Endocrine: Hypothyroidism (5-15%), gynecomastia, menstrual irregularities
• Dermatological: Rash, photosensitivity, acneiform eruptions
• Ophthalmological: Optic neuritis, blurred vision, diplopia
• Metabolic: Hypoglycemia, pellagra-like syndrome

Drug interaction

Ethionamide potentiates effects of other hepatotoxic medications including isoniazid, pyrazinamide, rifampin, and certain antifungals. It may increase concentrations of phenytoin, leading to toxicity. Concurrent use with cycloserine may exacerbate neurological and psychiatric adverse effects. Alcohol consumption increases risk of hepatitis and should be avoided. Diabetic medications may require adjustment due to hypoglycemic effects. Disulfiram-like reaction may occur with alcohol. Vitamin B6 supplementation is recommended to mitigate neuropathic effects.

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, the missed dose should be skipped and the regular dosing schedule resumed. Patients should never double the dose to make up for a missed one. Consistent adherence is critical to prevent development of further resistance, so any pattern of missed doses should be discussed with the healthcare provider to address potential barriers to adherence.

Overdose

Symptoms of overdose may include severe nausea and vomiting, neurological symptoms such as dizziness, seizures, or psychiatric manifestations. There is no specific antidote for ethionamide overdose. Management is supportive and symptomatic, including gastric lavage if presented early, activated charcoal, and appropriate symptomatic treatment. Hospitalization may be required for severe cases. Hemodialysis is not effective due to high protein binding. Liver function tests and neurological status should be monitored closely.

Storage

Store at controlled room temperature between 15-30°C (59-86°F) in the original container. Protect from light and moisture. Keep tightly closed and out of reach of children. Do not use if tablets show signs of discoloration or deterioration. Dispense only in the original container with child-resistant closure. Do not transfer to other containers. Properly discard any unused medication after treatment completion or expiration date.

Disclaimer

This information is for educational purposes and does not replace professional medical advice. Treatment decisions must be made by qualified healthcare providers based on individual patient circumstances. Dosage and administration may vary based on specific clinical situations. Patients should consult their healthcare provider for personalized medical advice. The manufacturer is not liable for any consequences arising from the use or misuse of this information.

Reviews

“Trecator SC remains an essential component of our MDR-TB treatment arsenal. While side effect management requires vigilance, its efficacy in difficult cases is well-established.” - Infectious Disease Specialist, TB Reference Center

“Patient tolerance varies significantly, but with proper dose escalation and supportive medications, most can complete therapy. The twice-daily dosing supports adherence.” - TB Program Coordinator

“Despite newer agents, ethionamide continues to have a role in complex resistance patterns. Its cost-effectiveness makes it accessible in resource-limited settings.” - Global Health Physician