Indotetra

Approved Indications:

• Bacterial Infections (Susceptible Strains):
• Respiratory tract infections (e.g., bronchitis, pneumonia)
• Urinary tract infections (UTIs)
• Skin and soft tissue infections
• Acne vulgaris (moderate to severe)
• Sexually transmitted infections, including chlamydia and syphilis (alternative)
• Gastrointestinal infections (e.g., cholera, traveler’s diarrhea)
• Rickettsial infections (e.g., Rocky Mountain spotted fever, typhus, Q fever)
• Brucellosis (with aminoglycoside)
• Plague and tularemia (alternative or combination use)
• Anthrax (including post-exposure prophylaxis)

Off-Label / Clinically Accepted Uses:

• Helicobacter pylori eradication (in quadruple therapy regimens)
• Malaria prophylaxis and treatment (when other agents are unsuitable)
• Lyme disease (early and disseminated stages)
• Periodontitis (topical dental application or adjunctive systemic therapy)

General Adult Dosage (Oral):

• Usual dose: 250–500 mg every 6 hours
• Severe infections: 500 mg every 6 hours
• Acne: 250–500 mg twice daily for initial treatment; maintenance doses vary
• H. pylori (quadruple therapy): 500 mg 4 times daily for 14 days (as part of regimen)
• Post-exposure anthrax prophylaxis: 500 mg twice daily for 60 days

Pediatric Dosage (Above 8 years):

• 25–50 mg/kg/day divided into 4 doses (maximum 2 g/day)

Elderly:

• Same as adults; monitor renal and hepatic function for dose adjustment

Renal Impairment:

• Use with caution; dose reduction may be required in severe renal dysfunction

Hepatic Impairment:

• Avoid high doses; monitor liver function

Administration:

• Oral: Take with a full glass of water to reduce esophageal irritation
• Avoid administration with milk, antacids, or iron-containing products
• IV form (Tetracycline HCl for injection) available but less commonly used

Tetracycline Hydrochloride is a broad-spectrum bacteriostatic antibiotic that inhibits bacterial protein synthesis. It binds reversibly to the 30S ribosomal subunit of susceptible bacteria, preventing the attachment of aminoacyl-tRNA to the mRNA-ribosome complex. This interference halts the addition of amino acids to the growing peptide chain, thereby inhibiting protein synthesis essential for bacterial growth and replication. The drug's effect is primarily bacteriostatic, though it may be bactericidal at high concentrations against some organisms.

• Absorption: 60–80% bioavailability after oral administration
• Onset of Action: Within 1–2 hours after oral intake
• Distribution: Widely distributed in body tissues and fluids; crosses placenta; binds to plasma proteins (~65%)
• Metabolism: Hepatic (minimal); primarily excreted unchanged
• Half-Life: 6–11 hours
• Elimination:
• Renal: 60% via urine (unchanged)
• Fecal: 23–40%
• Biliary excretion also occurs

• Pregnancy: Category D (US FDA) – Evidence of fetal risk; avoid use during pregnancy, especially after the second trimester, due to potential for permanent tooth discoloration and inhibition of bone growth in the fetus.
• Lactation: Excreted in breast milk; may affect bone and teeth development in nursing infants. Avoid if possible, especially during prolonged therapy. Use only if clearly needed and for short durations.

• Primary Class: Tetracycline Antibiotic
• Subclass: First-generation tetracycline

• Known hypersensitivity to tetracyclines
• Children under 8 years (risk of tooth discoloration and bone growth inhibition)
• Pregnancy (especially second and third trimesters)
• Severe hepatic dysfunction
• Concurrent use with retinoids (e.g., isotretinoin) due to risk of pseudotumor cerebri

• Tooth discoloration and enamel hypoplasia (in children and fetus)
• Photosensitivity: Increased risk of sunburn; advise sun protection
• Superinfection: Long-term use may lead to fungal or bacterial superinfections
• Pseudotumor cerebri: Monitor for signs (headache, blurred vision); discontinue if suspected
• Hepatotoxicity: Monitor liver function in prolonged or high-dose therapy
• Renal Impairment: Risk of accumulation; use cautiously
• Esophageal irritation/ulceration: Ensure administration with water and avoid lying down immediately after

Common (≥1%):

• Gastrointestinal: Nausea, vomiting, diarrhea, epigastric discomfort
• Dermatologic: Photosensitivity, rash
• Oral: Glossitis, stomatitis, black hairy tongue
• Musculoskeletal: Tooth discoloration (children), delayed bone growth (infants)

Serious/Rare:

• Hepatotoxicity (especially in high doses or IV use)
• Renal toxicity (with outdated tetracycline – Fanconi syndrome)
• Hypersensitivity reactions (urticaria, angioedema, anaphylaxis)
• Intracranial hypertension (pseudotumor cerebri)
• Blood disorders: Hemolytic anemia, thrombocytopenia, eosinophilia

• Decreased absorption with:
• Antacids (containing calcium, magnesium, aluminum)
• Iron supplements
• Dairy products (calcium)
• Bismuth subsalicylate
• Increased risk of hepatotoxicity with:
• Methoxyflurane (avoid combination)
• Other hepatotoxic drugs
• Anticoagulants (e.g., warfarin): Potentiated anticoagulant effect; monitor INR
• Oral contraceptives: May reduce effectiveness; recommend backup contraception
• CYP450 Interaction: Minimal; tetracycline is not a major CYP substrate, inhibitor, or inducer

• No major recent changes to tetracycline hydrochloride guidelines in the past few years
• Preference for doxycycline in newer clinical protocols due to better GI tolerance and once/twice-daily dosing
• Tetracycline remains included in quadruple H. pylori regimens as a cost-effective option in updated global guidelines
• Caution reaffirmed regarding pseudotumor cerebri and avoidance in pregnancy and young children

• Temperature: Store at 20°C to 25°C (68°F to 77°F); excursions permitted to 15°C–30°C
• Humidity/Light: Protect from moisture and direct sunlight
• Handling: Keep tightly closed in a dry, light-resistant container
• Special Instructions:
• Do not use outdated tetracycline (risk of nephrotoxicity – Fanconi syndrome)
• Oral suspension: Shake well before use (if available in liquid form)