Learning Objectives• Discuss the pathogens Tetracyclines are used to treat and how they act on those pathogens.• Identify the three common adverse effects of using tetracyclines.• Identify three considerations for educated a patient on the use of tetracyclines.
Tetracylines• Tetracyclines are broad spectrum antibiotics having an effect on a wide range of gram-positive and gram- negative bacteria.• Sensitive to rickestial diseases (e.g. Rocky Mountain Spotted fever and thyphus fever), Chylamydia, trachomatis, Brucella species, cholera, Mycoplasma pneumoniae, Lyme disease, Helicobacter pylori, anthrax, et al. (Lehne, 981)
Method of Action• Tetracylines are bacteriostatic- they prevent the further growth of bacteria.• Inhibit bacteria’s ability to synthesize protein.• Bind to the 30s ribosomal subunit and prevent the transfer of RNA from binding to the messenger RNA- ribosomal complex. (Lehne, 981)
Therapeutic Uses• Treatment for Acne • Suppresses the growth of Propionibacterium acnes. • Given topically and orally. • Oral doses are low for acne. (Lehne, 981)• Treatment for Peptic Ulcer Disease • To eliminate Helicobacter pylori. • A second line treatment. • Given in combination with metronidazole and bismuth subsalicylate (Segarra-Newnham,& Coakley, 187)
Therapeutic Uses• Treatment for Periodontal Disease • Doxycyline can be given orally and topically. • Minocyline is used topically. • Small oral dose to inhibit collagenase from harming the connective tissue of the gums. • Topical treatments suppress bacterial growth and are directly applied to site of periodontal disease.
Pharmacokinetics• Absorption is affected by food.• Become insoluble with calcium, iron, magnesium, aluminum, and zinc. (Lehne, 983)• Readily cross the placenta.• Eliminated by kidneys and liver. – Excreted by liver into bile. – Reabsorbed in the intestines. – Ultimately excreted in urine. – Can accumulate toxic levels in kidneys.
Adverse Effects• GI irritation • Tetracyclines can irritate the gastrointestinal tract. • Oral administration can cause abdominal pain, nausea, vomiting, and diarhea. • Esophageal ulceration. – Nursing Consideration- • May have to take with some food despite effects on absorption. • To avoid esophageal ulceration avoid given at bedtime.
Adverse Effects• Bones and Teeth • Bind to calcium in developing teeth and cause yellow or brown discoloration. • Can decrease tooth enamel. • Suppress long bone growth in premature infants. (Lehne, 982-3) – Nursing Considerations • Avoid with children under the age of 8 years. • Avoid with pregnant women.
Adverse Effects• Superinfections • Because tetracyclines are broad-spectrum they can destroy all good bacteria, leaving an overgrowth of drug resistant microbes. • Common culprits are: • Staphylococci (MRSA) • Clostridium difficile • Candida albicans • Staphylococci and C.difficile effect the bowel causing severe diarhea. • C. albicans can cause vaginal itching, lesions in anogenital area, or oral thrush. – Nursing Considerations • If violent diarrhea occurs notify physician . • Monitor for signs of dehydration. • Expect to administer Flagyl and Vancomycin for C.difficile.
Adverse Effects• Hepatotoxicity • Can cause fatty liver, lethargy, and jaundice. • Pregnant and Postpartum women with kidney disease are at highest risk.• Renal Toxicity • Exacerbate renally impaired patients.• Photosensitivity • Increase the skin’s sensitivity to UV light and exacerbate sunburns. – Nursing considerations • Educate patients to avoid too much sun light, wear sun protective clothing and generously apply sunscreen.• Rare side effects • Hemolytic anemia, bone marrow depression, anaphylaxis, intracranial hypertension.
Drug and Food Considerations• Absorption is affected by food except for doxycyline and minocycline.• Give on an empty stomach 1 hour before or 2 hours after a meal.• Avoid taking with milk, calcium supplement, magnesium supplements or magnesium containing laxatives, and most antacids.• Wait at least 2 hours between ingestion of these products and taking tetracyclines.• Decrease the effectiveness of penicillin G and oral contraceptives.• When combined with methoxyflurane renal toxicity increases.• Increases the potency of dioxin. (Karch, 119)
Differences Amongst Tetracylines• Tetracycline • Contraindicated for patients with renal dysfunction.• Demeclocycline • Stimulates urine flow. • Used for patients who have SIADH.• Doxycyline • Long acting. • Can be administered daily. • Can be given with food and milk. • Safe for patients with renal dysfunction.• Minocycline • Long acting. • Can be given with food • Safe for patients with renal failure • Can cause damage to vestibular system leading to dizziness, lightheadedness, and unsteadiness.
Test Questions• Which of these patients is would most likely be treated with tetracyline? A. A 7-year-old recently diagnosed with Lyme disease B. A 17-year-old adolescent suffering from acne vulgaris. C. A 28-year-old post-partum mother who is breastfeeding and has sinusitis D. A 52-year-old man on dialysis who was recently diagnosed with chlamydia tracomatis.
Test Questions• Which statement by a patient taking tetracycline demonstrates the patient’s ability to comply with the medication regimen? A. “If my stomach hurts when I take my pill I will just take Tums with it.” B. “I will practice a barrier method of contraception while I am taking this medicine. C. “I will start my medicine before I going tanning tomorrow.” D. “I will stop taking the pills as soon as I feel better.”
Test Questions• A patient should immediately stop taking tetracycline and call their doctor if they get: A. A bad sunburn B. Nausea 30 minutes after taking their pill C. Frequent liquid stools with diarrhea D. A metallic taste in the mouth
References• Karch, A. (2011). Focus on nursing pharmacology (5th ed.). Philidephia, PA: Wolters Kluwer | Lippincott Williams & Wilkins.• Lehne, R.A. (2007). Pharmacology for nursing care (6th ed.). St.Louis, MO: Saunders Elsevier.• Segarra-Newnham, M. & Coakley, C. (2012). Salvage options for eradication of helicobacter pylori during tetracycline back order. Journal of Pharmacy Technology, 28 (5): 187-92.