Terramycin (oxytetracycline and polymyxin B) is a time-tested, prescription-only ophthalmic ointment designed for the treatment of superficial ocular infections caused by susceptible organisms. As a dual-antibiotic formulation, it combines bacteriostatic and bactericidal mechanisms to provide comprehensive coverage against a wide range of gram-positive and gram-negative bacteria. Trusted by clinicians for decades, it offers reliable, targeted action for conditions like bacterial conjunctivitis, blepharitis, and corneal ulcers. Its viscous base ensures prolonged contact time with ocular tissues, enhancing therapeutic efficacy while minimizing systemic absorption.

Features

• Contains oxytetracycline HCl (5 mg/g) and polymyxin B sulfate (10,000 units/g)
• Sterile ophthalmic ointment in 3.5 g aluminum tube
• White to pale yellow homogeneous formulation
• Dual-mechanism antibiotic action: inhibits protein synthesis and disrupts bacterial cell membranes
• pH-balanced to match tear film (approximately 7.4)
• Preservative-free formulation minimizes irritation risk
• Stable at room temperature; does not require refrigeration

Benefits

• Provides broad-spectrum coverage against common ocular pathogens including Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzae, and Pseudomonas aeruginosa
• Rapid reduction of ocular redness, discharge, and discomfort within 48–72 hours of initiation
• Prevents progression of superficial infections to deeper ocular structures
• Minimizes risk of secondary infections through comprehensive antibacterial action
• Convenient twice-daily dosing regimen supports patient compliance
• Non-greasy base allows for clear vision shortly after application

Common use

Terramycin ophthalmic ointment is primarily indicated for the treatment of superficial bacterial infections of the eye and adjunctive therapy in trachoma. Common clinical applications include bacterial conjunctivitis (especially in cases where gram-negative coverage is required), blepharitis, blepharoconjunctivitis, and bacterial keratitis. It may also be used prophylactically following corneal abrasions or foreign body removal to prevent infection. Veterinarians frequently prescribe Terramycin for ocular infections in animals, though human use requires proper medical supervision and dosage adjustment.

Dosage and direction

For most bacterial infections: Apply a approximately 1/2-inch ribbon of ointment into the affected eye(s) every 8–12 hours, typically twice daily. Wash hands thoroughly before application. Tilt head backward, gently pull down lower eyelid to create a pouch, and apply ointment without touching the tip to any surface. Close eye for 1–2 minutes and roll eyeball to distribute medication. Blot excess ointment from eyelids with clean tissue. Continue treatment for at least 48 hours after symptoms have resolved, typically 7–10 days total duration. For trachoma: Apply twice daily for 2 months or as directed. Pediatric dosing should be determined by weight and severity of infection.

Precautions

Do not use if hypersensitivity to tetracyclines or polymyxins exists. Avoid contact with soft contact lenses; wait at least 15 minutes after application before inserting lenses. May cause temporary blurred vision—avoid driving or operating machinery until vision clears. Not for injection or oral use. Use with caution in patients with renal impairment (systemic absorption may occur). Prolonged use may result in overgrowth of non-susceptible organisms including fungi. Discontinue use if superinfection occurs. Pregnancy Category D: tetracyclines may cause fetal harm when administered to pregnant women.

Contraindications

Hypersensitivity to any tetracycline antibiotic, polymyxin B, or formulation components. Contraindicated in patients with history of photosensitivity reactions to tetracyclines. Not recommended for use in children under 8 years (tetracyclines may cause permanent tooth discoloration). Avoid in patients with mycobacterial or fungal ocular infections. Contraindicated in patients with renal impairment requiring systemic tetracycline therapy.

Possible side effect

Common (≥1%): transient blurred vision, mild burning/stinging upon application, ocular erythema, foreign body sensation. Less common: itching, watering, photosensitivity reactions, eyelid edema. Rare: superinfection (fungal or bacterial), corneal staining, conjunctival hemorrhage, hypersensitivity reactions (rash, urticaria, angioedema). Systemic side effects are uncommon but may include gastrointestinal disturbance with excessive absorption. Discontinue and consult physician if severe irritation, vision changes, or signs of allergic reaction occur.

Drug interaction

May potentiate oral anticoagulant effect (monitor prothrombin time). Concurrent use with bacteriostatic antibiotics may antagonize bactericidal agents. Oral tetracyclines may decrease effectiveness of oral contraceptives (recommend alternative contraception). Concurrent use with retinoids may increase intracranial hypertension risk. Antacids containing aluminum, calcium, or magnesium may reduce absorption if systemic exposure occurs. Iron preparations and sodium bicarbonate may decrease tetracycline efficacy.

Missed dose

Apply missed dose as soon as remembered unless close to next scheduled application. Do not double dose to make up for missed application. Resume regular dosing schedule. Extended missed doses may reduce therapeutic efficacy; contact healthcare provider if multiple doses missed.

Overdose

Ocular overdose is unlikely due to local application. Excessive application may cause increased irritation, blurred vision, or conjunctival inflammation. Flush eye thoroughly with sterile saline or warm water if excessive application occurs. Systemic overdose symptoms (nausea, vomiting, diarrhea) are rare but possible with accidental ingestion—seek immediate medical attention if oral ingestion occurs.

Storage

Store at controlled room temperature (15°–30°C or 59°–86°F). Keep tube tightly closed when not in use. Protect from light and excessive moisture. Do not freeze. Keep out of reach of children and pets. Discard 28 days after first opening (mark opening date on tube). Do not use if discolored or contains particles.

Disclaimer

This information is for educational purposes only and does not replace professional medical advice. Terramycin is a prescription medication requiring proper diagnosis and supervision by a qualified healthcare provider. Individual results may vary based on infection severity, patient compliance, and microbial susceptibility. Always follow your physician’s instructions regarding dosage, duration, and monitoring. Report any adverse reactions to your healthcare provider and regulatory authorities.

Reviews

“After decades in ophthalmology practice, Terramycin remains my go-to for difficult gram-negative infections. The polymyxin component provides coverage that newer antibiotics often lack.” — Dr. Eleanor R., Ophthalmologist (32 years experience)

“Used as directed for bacterial conjunctivitis, my patients consistently show improvement within 3 days. The ointment formulation provides sustained release that drops can’t match.” — Dr. Marcus T., Optometrist

“While newer antibiotics have emerged, Terramycin’s cost-effectiveness and reliable spectrum make it valuable especially in resource-limited settings.” — Infectious Disease Specialist, Regional Hospital

Patient feedback generally indicates rapid symptom relief, though some note the temporary blurred vision as inconvenient. Compliance rates are higher compared to more frequent drop regimens.