II. Indications
- Skin disorders
- Gastrointestinal disorders
- Helicobacter Pylori (part of quadruple therapy protocol)
- Tick-borne illness
- Miscellaneous disorders
- Sexually Transmitted Disease
III. Contraindications
- Pregnancy
- Pregnancy category D
- Children under age 8 years old
- AAP now approves Doxycycline for ANY age up to 21 day duration
- Unlike Tetracycline, Doxycycline is unlikely to cause visible tooth staining
- For severe infections (e.g. Lyme Disease, Rocky Mountain Spotted Fever), Doxycycline is a first-line agent
IV. Mechanism
- Bacteriostatic
- Tetracyclines are Protein synthesis inhibitors, binding the 30S ribosomal subunit of susceptible Bacteria
- Prevents elongated peptide chains from forming from Amino Acid residues
- Inhibits Amino Acid-linked tRNA from binding at the Ribosomal A Site
V. Preparations: Tetracycline
- Acne Vulgaris: 1 gram orally daily given in 2-4 divided doses
VI. Preparations: Doxycycline
- See Doxycycline
- Typical dose: 100 mg orally twice daily
- Low doses, such as 50 mg daily, are often as effective for acne
- Avoid substituting low-dose Doxycycline (Periostat, Oracea) products for systemic infections
- May substitute other Doxycycline salts
- Doxycycline hyclate (Vibramycin, Doryx)
- Doxycycline monohydrate (Monodox)
- (2013) Presc Lett 20(5):26
- Other formulations
- Doxycyline Hyclate Delayed-Release (Doryx MPC)
- Expensive ($10/pill) formulated to by-pass the esophagus for less side effects
- Alternatively, take the doxycyline with 8 oz water and food
- (2016) Presc Lett 23(11)
- Doxycyline Hyclate Delayed-Release (Doryx MPC)
VII. Preparations: Minocycline (Minocin)
- Oral
- Acne Vulgaris: 50-200 mg/d orally in divided doses
- Topicals
- Acne Vulgaris: Minocycline 4% Foam (Amzeeq)
- Rosacea: Minocycline 1.5% Foam (Zilxi)
- Very expensive (nearly $500 for 30 grams)
- No evidence of benefit over other Rosacea topicals
- (2021) Presc Lett 28(6): 36 [PubMed]
VIII. Preparations: Intravenous
- Eravacycline (Xerava)
- Nuzyra (Omadacycline)
- Load: 200 mg IV for one dose (or divided 100 mg IV every 12 hours for 2 doses)
- Maintenance: 100 mg IV once daily (or 300 mg orally once daily)
- Once daily agent indicated for Community Acquired Pneumonia and Skin Infections
- Released in 2018 at $400 per pill, and likely less effective than standard agents for CAP
- (2019) presc lett 26(1):4
IX. Drug Interactions: Food Related
- Tetracycline
- Milk and Calcium-rich food decrease absorption
- Take 1 hour before or 2 hours after a meal
-
Doxycycline and Minocycline
- Can be taken with milk or food (unlike Tetracycline)
X. Drug Interactions
-
Warfarin
- Increases INR
XI. Precautions
- Use Sunscreen with these agents due to Drug-induced Photosensitivity
-
Pill Esophagitis
- Take with a full glass of water
XII. Adverse Effects
-
General
- Pseudotumor Cerebri (rare)
- Tetracycline
- Photosensitivity
- Interferes with OCP action
- Tooth Discoloration (Children under age 8 years)
- Tooth enamel hypoplasia
- Rare with Doxycycline
-
Doxycycline
- Photosensitivity
- Abdominal Pain
- Diarrhea
- Pill Esophagitis (see above)
- Minocycline
- Generally well tolerated
- Does not generally cause photosensitivity
- Minocycline-Induced Hyperpigmentation
- Blue-gray or muddy brown Hyperpigmentation resulting from Minocycline-iron complex skin deposition
- Distribution: Face, arms, legs (esp. shins)
- Highest risk in long-term dosing for chronic infection or Rheumatoid Arthritis (risk increases with longer duration)
- Uncommon with low dose Acne Vulgaris use
- Hyperpigmentation often persists even after Minocycline is discontinued (limited therapies, e.g. laser)
- Jain (2019) Am Fam Physician 100(4): 239-240 [PubMed]
- Rare adverse effects
- Lupus-Like Syndrome (1:20,000)
- Vertigo
- Oral Mucosa pigmentation (blue-black pigmentation)
- Hypersensitivity Syndrome within 1-3 months
- Delayed Arthralgias or Polyarthritis
- Omadacycline (Nuzyra)
XIII. References
- (2019) Tarascon Pharmacopeia, accessed 3/31/2019
- LoVecchio (2019) Crit Dec Emerg Med 33(3): 28
Images: Related links to external sites (from Bing)
Related Studies
tetracycline (on 12/21/2022 at Medicaid.Gov Survey of pharmacy drug pricing) | ||
TETRACYCLINE 250 MG CAPSULE | Generic | $0.66 each |
TETRACYCLINE 500 MG CAPSULE | Generic | $0.95 each |
minocycline (on 12/21/2022 at Medicaid.Gov Survey of pharmacy drug pricing) | ||
MINOCYCLINE 100 MG CAPSULE | Generic | $0.36 each |
MINOCYCLINE 50 MG CAPSULE | Generic | $0.18 each |
MINOCYCLINE 75 MG CAPSULE | Generic | $0.35 each |
MINOCYCLINE HCL 100 MG TABLET | Generic | $1.29 each |
MINOCYCLINE HCL 50 MG TABLET | Generic | $1.17 each |