Only doxycycline and minocycline, which are members of the tetracyclines
family, can be used with patients who have renal problems. Other members of
the tetracycline family should not be prescribed for those patients.
Tetracyclines should be taken with a full glass of water on an empty stomach.
It should not be administered an hour before meals or two hours after meals
except for doxycycline and minocycline.
The patient should not be given antacids containing aluminum, calcium, or
magnesium, laxatives, iron products, food, or milk or other dairy products for
1 hour before or 2 hours after tetracycline is administered.
Doxycycline and oxytetracycline can be administered IV. Doxycycline may
be given in concentrations not less than 100μ g or > than 1 mg/mL. Don’t admin-
ister doxycycline IM or SQ. Oxytetracycline needs to be diluted in at least
100 mL of appropriate IV solution. Don’t infuse rapidly.
Tetracycline may be administered IM not exceeding 2 ml at each injection
site. Don’t administer tetracycline IV or SQ.
The patient should be provided with the same instructions as those given to
a patient who is receiving penicillin (see Penicillin and Patient Education).
However, also advise the patient to avoid direct sunlight and ultraviolet light
because tetracyclines might cause the patient to become sensitive to sunlight.
The patient should use sunscreen in the sun.
Advise the patient to discard unused tetracycline because tetracyline becomes
toxic as it decomposes. Tetracycline should be taken on an empty stomach as
food affects absorption of the drug.
Tetracyclines and Drug-Drug Interactions
Tetracyclines can interact with other medications. Avoid giving tetracyclines two
hours before or after the patient receives colestipol (Colestid) or cholestyramine
(Questran) because these medications decrease the absorption of tetracycline.
Give tetracycline 1–3 hours before or after giving the patient antacids, calcium
supplements, choline and magnesium salicylates, iron supplements, magnesium
salicylate, or magnesium laxatives, foods containing milk and milk products.
These lower the absorption of tetracycline.
Don’t give tetracycline if the patient is taking estrogen-containing oral con-
traceptives since this reduces the contraceptive effectiveness and may result in
breakthrough bleeding. Female patients should be advised to use alternative
methods of birth control while on antibiotics.
CHAPTER 13 Antimicrobials—Fighting Infection^233