Tetracyclines

Hi!

This is the outline that Sunmin and I have made for our project on tetracyclines.  Please let me know if we have any incorrect information, are missing anything important, or if there is anything we should remove from the presentation.

Thank you very much for your help!

Tetracyclines

Origin

• ·      Isolated from Streptomyces aureofaciens bacteria in 1948
• ·      First broad-spectrum antibiotics.

Action

• ·      Tetracyclines inhibit bacterial protein synthesis and have a bacteriostatic effect.

Indications

• ·      Short-Acting Tetracycline [tetracycline (Sumycin)]:
• o  infections caused by gram-positive and gram-negative bacteria, respiratory and skin disorders, chlamydial infection, gonorrhea, syphilis, and rickettsial infections.
• ·      Intermediate-Acting Tetracycline [demeclocycline HCL (Declomycin)]:
• o   gram-positive and gram-negative bacteria.
• ·      Long-Acting Tetracyclines [doxycycline hyclate (Vibramycin), minocycline HCL (Minocin)]:
• o   bacterial infections and acne.

Route

• ·      Oral: newer tetracyclines (doxycycline and minocycline) are absorbed rapidly and completely
• ·      IM: seldom used, causes pain at injection site
• ·      IV: used for treatment of severe infections

Side effects

• ·      GI disturbances, such as nausea, vomiting, diarrhea, heartburn, and abdominal discomfort
• ·      Photosensitivity can occur, especially with demeclocycline (Declomycin).
• ·      Ototoxicity is possible with Minocycline (Minocin), which can damage the vestibular part of the inner ear, resulting in difficulties with balance.
• ·      Nephrotoxicity (Kidney toxicity) can occur when tetracycline is given in high doses with other nephrotoxic drugs
• ·      Super infections can result from the disruption in the body’s normal microbial flora

Contraindications

• ·      Pregnancy: Tetracycline can be teratogenic when taken during the first trimester.
• ·      Children younger than 8: tetracycline can irreversibly discolor the permanent teeth. Women in the last trimester of pregnancy should also avoid tetracycline for this reason.
• ·      Hypersensitivity, severe hepatic or renal disease

Nursing Implications

• ·      Assessment

·      Assess vital signs and urine output.

·      Check laboratory results, especially renal and liver function (BUN, serum creatinine, AST, ALT, and bilirubin).

·      Obtain a diet and drug history. Drug absorption is decreased in the presence of dairy products, antacids, iron, calcium, and magnesium.  Tetracyclines increase digoxin absorption, which could lead to digitalis toxicity.

• ·      Nursing Interventions

·      Obtain a culture from the infected area for a culture and sensitivity test. Antibiotic therapy can be started after cultures are taken.

·      Tetracycline should be administered 1 hour before or 2 hours after meals for optimum absorption.

Patient teaching

• ·      Tetracyclines should not be taken with magnesium or aluminum based antacids, milk products or other drugs high in calcium, or drugs containing iron.  These substances prevent absorption of the drug.
• ·      Tetracycline should be taken on an empty stomach 1 hour before or 2 hours after meals.
• ·      Doxycycline and minocycline absorption is improved when taken with food.
• ·      Patients should not take tetracyclines if they are pregnant due to possibly teratogenic effects.
• ·      Tetracycline can decrease the effectiveness of birth control pills. Patients should use a second method of birth control while taking tetracyclines.
• ·      Patients should tell their doctor if they are breast-feeding.  Tetracycline passes into breast milk and may affect bone and tooth development in a nursing baby.
• ·      Tetracycline should not be given to children younger than 8 years old, because it can cause permanent yellowing or graying of the teeth, and can affect a child's growth.
• ·      Tetracycline can cause sunburn.  Patients should avoid exposure to sunlight or artificial UV rays (sunlamps or tanning beds) and wear sunscreen (minimum SPF 15) and protective clothing if they must be out in the sun.
• ·      Patients should not take iron supplements, multivitamins, calcium supplements, antacids, or laxatives within 2 hours before or after taking tetracycline.
• ·      Unused tetracycline should be thrown away. Expired tetracycline can be toxic and can cause a dangerous syndrome resulting in damage to the kidneys.
• ·      Tetracycline should be stored in a dark place away from extreme heat.

Interesting information

• ·      In 2006, Moyer reported that “Patients are more likely to acquire Clostridium difficile infection if they take imipenem, ceftazidine, clindamycin, or moxifloxacin…however, patients who take tetracycline are less likely to get C difficile.” 

References

Kee, J. L., Hayes, E. R., & McCuistion, L. E. (2012). Pharmacology. A nursing process approach. St. Louis, MO: Elsevier.

Moyer, P. (2006). Four antibiotics, in various classes, most likely to cause clostridium difficile infection. Retrieved from http://www.medscape.com/viewarticle/545269.