While adverse reactions to tetracycline are uncommon, some patients who take the drug may experience side effects, including headaches, gastrointestinal problems (stomach cramps, diarrhea), and dermal photosensitivity (increased skin sensitivity to sunlight). Tetracycline and other antibiotic medications have been known to cause yeast infections, so be on the lookout for symptoms like vaginal discharge, itching, or discomfort.
This is not a complete list of adverse effects – though these are among the most common. Seek medical attention right away if you experience symptoms such as abdominal pain, loss of appetite, nausea and vomiting, visual changes, or yellowing skin while taking tetracycline.
As with all prescription medication, be sure to inform the prescribing doctor about any medical conditions you have been previously diagnosed with, as well as any medication/ supplements you are currently taking before starting treatment with tetracycline. Tetracycline can interact with other forms of medication and substances, causing potentially serious side effects or life-threatening allergic reactions. Drug interactions can occur with blood thinners such as warfarin, certain retinoids, penicillin, and proton pump inhibitors among others.
Antacids and supplements containing calcium and magnesium can reduce the amount of tetracycline that your body absorbs, so be sure to take tetracycline 1–2 hours before or 1–2 hours after taking antacids or supplements.
Using tetracycline can cause your skin to become sensitive to sunlight or ultraviolet light, so try to avoid unnecessary exposure to the sun or UV rays (tanning beds) and do your best to wear protective clothing, sunglasses, or sunscreen that is SPF 15 or higher. Call your doctor if you notice redness, swelling, or blistering as a result of sun exposure while on tetracycline.
Oral contraceptives (birth control pills) with estrogen can lose effectiveness when combined with tetracycline, so unplanned pregnancy can occur.
In addition, let your doctor know if you are breastfeeding, pregnant or plan on becoming pregnant before starting treatment with this medication.