Drug Guide
Tetracycline Hydrochloride
Classification
Therapeutic: Antibiotic, antibacterial
Pharmacological: Tetracycline class, protein synthesis inhibitor
FDA Approved Indications
- Treatment of bacterial infections including urinary tract infections, respiratory tract infections, skin infections, and other susceptible bacterial infections
Mechanism of Action
Tetracycline binds reversibly to the 30S ribosomal subunit in bacteria, inhibiting protein synthesis by preventing the attachment of aminoacyl-tRNA to the mRNA-ribosome complex, thus exerting a bacteriostatic effect.
Dosage and Administration
Adult: Typically 250-500 mg every 6 hours, adjusted based on infection severity and susceptibility.
Pediatric: Based on weight; generally 25-50 mg/kg/day divided into 2-4 doses, with adjustments for age and renal function.
Geriatric: Adjust dosage based on renal and hepatic function; monitor for increased side effects.
Renal Impairment: Use with caution; dose adjustment may be necessary based on severity.
Hepatic Impairment: Use cautiously; monitor liver function.
Pharmacokinetics
Absorption: Well absorbed orally, with peak serum concentrations in about 2 hours.
Distribution: Widely distributed in body tissues and fluids, crossing the placenta; enters cerebrospinal fluid poorly.
Metabolism: Minimal hepatic metabolism.
Excretion: Primarily renal; some excreted in bile.
Half Life: Approximately 6-12 hours.
Contraindications
- Hypersensitivity to tetracyclines or any component of the formulation.
Precautions
- Use with caution in pregnant women, nursing mothers, children under 8 years, due to risk of teeth discoloration and bone growth inhibition.
- Monitor hepatic and renal function during prolonged therapy.
Adverse Reactions - Common
- Gastrointestinal upset (nausea, vomiting, diarrhea) (Common)
- Photosensitivity ( rash, sunburns) (Common)
Adverse Reactions - Serious
- Hepatotoxicity (Rare)
- Kidney toxicity, nephrogenic diabetes insipidus (Rare)
- Superinfection, including candidiasis (Rare)
- Fanconi syndrome (with high-dose or prolonged use) (Rare)
Drug-Drug Interactions
- Retinoids, isotretinoin possibly increase intracranial hypertension risk.
- Penicillin and other β-lactam antibiotics may have decreased efficacy.
Drug-Food Interactions
- Dairy products, antacids, and iron supplements can impair tetracycline absorption.
Drug-Herb Interactions
N/ANursing Implications
Assessment: Monitor for signs of superinfection, gastrointestinal disturbances, and hypersensitivity reactions.
Diagnoses:
- Risk for superinfection
- Impaired gastrointestinal function
Implementation: Administer on an empty stomach if possible, but with food if GI upset occurs. Ensure timed administration concerning food and supplements that interfere with absorption.
Evaluation: Assess infection resolution, monitor for adverse effects, and ensure adherence.
Patient/Family Teaching
- Advise to avoid dairy products, antacids, and iron preparations within 2 hours of dosing.
- Instruct to use sun protection due to photosensitivity.
- Complete the prescribed course of therapy.
- Report signs of superinfection or allergic reactions immediately.
Special Considerations
Black Box Warnings:
- Discoloration of teeth and potential for reduced bone growth in children under 8, pregnant women, and nursing mothers.
- Potential for causing intracranial hypertension, especially in children.
Genetic Factors: None specifically identified.
Lab Test Interference: May cause false decreases in serological tests for syphilis (e.g., VDRL, RPR).
Overdose Management
Signs/Symptoms: Gastrointestinal distress, superinfection, and hepatic toxicity.
Treatment: Supportive care, gastric lavage if recent ingestion, and monitoring of renal and hepatic function.
Storage and Handling
Storage: Store at room temperature, away from light and moisture.
Stability: Stable when stored correctly; check expiration date before use.