Tetracyclines
| Drug monograph · NCLEX study reference | |
| Therapeutic class | Antibacterial |
|---|---|
| Pharmacologic class | Tetracycline |
| Onset / peak / duration | Rapid; once or twice daily. |
| Half-life / level | Doxycycline about 18 hours; no routine level. |
| Routes | PO (oral), IV |
| High-alert (ISMP) | No |
| Black box warning | None |
| Antidote / reversal | Supportive care. |
| Pregnancy / lactation | Contraindicated. |
Nursing pharmacology study reference (NCLEX-style monograph). Numeric values are standard teaching ranges for study and must be verified against current manufacturer labeling before clinical use. This is educational content, not prescribing guidance.
Tetracyclines — Antibacterial; Tetracycline.
Identification
- Therapeutic class: Antibacterial.
- Pharmacologic class: Tetracycline.
Pharmacology
- Mechanism of action: Bind the 30S ribosomal subunit to inhibit protein synthesis (bacteriostatic).
- Onset / peak / duration: Rapid; once or twice daily.
- Half-life / therapeutic level: Doxycycline about 18 hours; no routine level.
Clinical use
- Indications: Respiratory infections, acne, tick-borne diseases (Rocky Mountain spotted fever, Lyme), chlamydia, malaria prophylaxis (doxycycline).
- Usual dose, route, frequency: Doxycycline PO once or twice daily; IV available.
- Maximum dose / adjustments: Avoid in children under 8 and in pregnancy.
Safety
- Contraindications: Pregnancy, lactation, children under 8 (tooth staining and bone effects), hypersensitivity.
- Black box warning: None.
- Interactions: Dairy, antacids, iron, and calcium bind the drug and reduce absorption (separate doses); warfarin, oral contraceptives, isotretinoin (intracranial hypertension).
- Pregnancy / lactation: Contraindicated.
- High-alert: No.
Adverse effects
- Common side effects: Photosensitivity, GI upset, esophageal irritation.
- Serious effects to report: Severe sunburn, esophageal ulceration, intracranial hypertension (headache, vision changes), C. difficile colitis.
- Antidote / reversal: Supportive care.
Nursing process
- Assessment before administration: Allergy, pregnancy status, age, photosensitivity risk.
- Interventions during therapy: Take with a full glass of water and remain upright; avoid dairy and binders around dosing.
- Monitor: Skin, GI tolerance, infection resolution.
- Evaluation / expected outcome: Resolution of infection or acne improvement.
Patient teaching
- Patient teaching: Use sun protection; do not lie down right after a dose; avoid dairy, antacids, and iron near dosing; backup contraception.
- Notify provider if: Severe headache or vision changes, painful swallowing, severe sunburn.
- Administration tips: Full glass of water, stay upright; separate from dairy and mineral binders by 2 hours.