Home Drug Guide Oxytetracycline

Drug Guide

Generic Name

Oxytetracycline

Brand Names Terramycin

Classification

Therapeutic: Antibiotic, Tetracycline class

Pharmacological: Protein synthesis inhibitor, bacteriostatic

FDA Approved Indications

Respiratory tract infections
Urinary tract infections
Skin infections
Ophthalmic infections
Anaplasmosis in cattle and sheep
Tick fever in dogs

Mechanism of Action

Oxytetracycline binds to the 30S ribosomal subunit, inhibiting the attachment of aminoacyl-tRNA to the mRNA-ribosome complex, thereby preventing protein synthesis and bacterial growth.

Dosage and Administration

Adult: Typically 250 to 500 mg every 6 to 12 hours, depending on infection severity and site.

Pediatric: Dosing based on weight, generally 25-50 mg/kg/day divided into 2-4 doses.

Geriatric: Adjust dose based on renal function, monitor for side effects.

Renal Impairment: Use with caution; dose adjustment may be necessary.

Hepatic Impairment: No specific adjustment recommended; monitor liver function during prolonged therapy.

Pharmacokinetics

Absorption: Orally absorbed with variable bioavailability; better absorption on an empty stomach.

Distribution: Widely distributed in body tissues and fluids, including cerebrospinal fluid and eye tissues.

Metabolism: Minimal hepatic metabolism.

Excretion: Primarily excreted unchanged in urine and feces.

Half Life: Approximately 8-12 hours.

Contraindications

Allergy to tetracyclines or other related antibiotics.

Precautions

Use with caution in pregnant women, nursing mothers, and children under 8 due to teeth discoloration and bone growth inhibition.
Monitor renal and hepatic function during prolonged therapy.

Adverse Reactions - Common

Gastrointestinal upset (nausea, vomiting, diarrhea) (Common)
Photosensitivity (Common)

Adverse Reactions - Serious

Hepatotoxicity (Rare)
Blood dyscrasias (Rare)
Superinfection (such as candida) (Rare)

Drug-Drug Interactions

Concurrent use with retinoids may increase intracranial pressure.
Calcium, magnesium, aluminum containing antacids and dairy products decrease absorption.

Drug-Food Interactions

Dairy products, antacids, iron supplements reduce bioavailability.

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor for signs of allergic reactions, superinfection, liver and kidney function, gastrointestinal disturbances.

Diagnoses:

Risk for superinfection
Impaired gastrointestinal mobility

Implementation: Administer with or without food as tolerated; avoid dairy and antacids around dosing times; monitor labs.

Evaluation: Assess resolution of infection and monitor for adverse effects.

Patient/Family Teaching

Take medication exactly as prescribed.
Avoid dairy and antacids close to medication times.
Report signs of allergic reactions, liver problems, or superinfection.
Use sunscreen and protective clothing to prevent photosensitivity reactions.

Special Considerations

Black Box Warnings:

Discoloration of permanent teeth and enamel hypoplasia in children under 8; avoid use unless no alternatives are available.
Hepatotoxicity and intracranial hypertension in certain populations.

Genetic Factors: No specific genetic considerations noted.

Lab Test Interference: May cause false elevations of urinary catecholamines and serum creatinine.

Overdose Management

Signs/Symptoms: Gastrointestinal distress, dehydration, dizziness, and superinfection.

Treatment: Supportive care, gastrointestinal decontamination if early, and monitoring renal function.

Storage and Handling

Storage: Store at controlled room temperature (20-25°C), away from moisture, heat, and light.

Stability: Stable under proper storage conditions.