Tetracyclines are broad-spectrum antibiotics that are bacteriostatic, subsequently inhibiting bacterial growth. There are a number of meds in this class, with a few common meds are doxycycline, tetracycline and minocycline.  The common suffix ‘-cycline’.

Indications for Use:

Tetracycline medications are useful for the treatment of many gram-positive and gram-negative infections, yet are limited due to the significance of side effects experienced by many clients.  They are used for treating a wide variety of infections including skin conditions such as acne, sexually transmitted infections (chlamydia, syphilis, gonorrhea), H. Pylori and Lyme disease.

Mechanism of Action:

Tetracyclines are bacteriostatic. They work by penetrating the bacterial cell wall and binding to the 30S ribosome, inhibiting the protein synthesis required to make the cellular wall (Werth, 2024).

Nursing Considerations:

Administration: well-absorbed after oral dosing. Take with plenty of water and on an empty stomach.  Do not take with dairy foods, antacids, calcium containing foods, vitamin or mineral supplements, as tetracycline absorption will be decreased by the metallic cations (aluminum, calcium, magnesium, iron) (Werth, 2024).  For bedtime doses, take one hour before bed and sit upright to avoid esophageal irritation.

IV route available for minocycline, twice a day dosing.

The dosing for each type of tetracycline differ widely, due to different absorption and distribution.

Tetracyclines are contraindicated in later term pregnancy and for children ages 8 and under. This is due to the permanent staining of teeth.  Short term use (less than 21 days) of doxycycline in children has been shown to not cause tooth discoloration.

Lactation: Small amounts may be excreted in breast milk.

Caution if renal impairment, dose adjustments need to be made.

Drug interactions:

There are numerous drug interactions with tetracyclines. These include:

• warfarin effects may be increased. Closer monitoring of INR should be ordered.
• oral contraceptives that contain estrogen: effectiveness will be decreased. Have a back up method in place.
• meds that decrease effectiveness of tetracyclines include bile acid sequestrants (cholestyramine), antacids, sucralfate, barbiturates and phenytoin. Compounds that include calcium, magnesium, iron, zinc, aluminum can also form insoluble compounds and decrease tetracycline’s effectiveness (Vallerand & Sanoski, 2024).

Adverse/ Side Effects:

All oral tetracyclines cause nausea, vomiting, and diarrhea. Monitor diarrhea and report any significant changes with bowel movements and if diarrhea contains blood or pus.

Other adverse effects include:

• Oral candida superinfections and esophageal erosions can occur so ensure to take with plenty of water. 
• Discolouration of developing teeth and enamel hypoplasia in children under 8.Abnormal bone growth may also occur.
• Doxycycline may be safe if taken for less than 21 days and benefits outweigh risk.
• Photosensitivity may manifest as an exaggerated sunburn.
• Fatty liver 
• Vestibular dysfunction (with minocycline)

(Werth, 2024; Vallerand & Sanoski, 2024)

Client Teaching:

• Take the med as prescribed. Do not stop taking the med even if feeling better.
• Take with a large glass of water.
• Take on an empty stomach and especially avoid taking the med with food that contain dairy, calcium or iron.
• Numerous med interactions, so avoid taking the med with other drugs.
• Take one hour before bedtime to avoid esophageal irritation.
• Avoid direct sunlight exposure and wear sunscreen to prevent skin sensitivities.
• Clients who are on oral contraceptives should be educated that tetracyclines may impede the effectiveness of the oral contraceptive and an alternative measure of birth control should be utilized while on the antibiotic.
• Female clients must be aware to immediately stop tetracycline if they become pregnant.  Expired tetracycline should be immediately disposed of as it can become toxic.
• Expired tetracycline pills can degenerate and, if ingested, cause Fanconi syndrome (defect in renal proximal tubular reabsorption).  Patients should be instructed to discard the antibiotics when they expire.
• Report any hypersensitivity reactions such as a rash, hives, swelling. Report any change in bowel patterns such as diarrhea.

(Weth, 2024; Vallerand & Sanoski, 2024)

Tetracycline Medication Card

Now let’s take a closer look at the medication card for tetracycline.^[4][5] Because information about medication is constantly changing, nurses should always consult evidence-based resources to review current recommendations before administering specific medication.

To help with comparing the medications and to learn important considerations for each medication, refer to the Chapter 12 Antimicrobials Medication Cards.

References