Doxycycline Hyclate

Last updated on RxList: 10/26/2020

What is Doxycycline Hyclate and how is it used?

Doxycycline Hyclate is a prescription medicine used to treat the symptoms of respiratory tract infections, sexually transmitted infections, specific bacterial infections and Rickettsial infections. Doxycycline Hyclate may be used alone or with other medications.

Doxycycline Hyclate belongs to a class of drugs called Tetracycline Antibacterial.

It is not known if Doxycycline Hyclate is safe and effective in children younger than 8 years of age or weighing at least 99 lbs (45 kg).

What are the possible side effects of Doxycycline Hyclate?

Doxycycline Hyclate may cause serious side effects including:

  • difficulty swallowing,
  • headache,
  • blurred vision,
  • vision loss, and
  • double vision

Get medical help right away, if you have any of the symptoms listed above.

The most common side effects of Doxycycline Hyclate include:

  • weight loss,
  • nausea,
  • vomiting,
  • diarrhea,
  • rash,
  • skin sensitivity to sunlight,
  • hives,
  • anemia, and
  • vaginal yeast infection
Tell the doctor if you have any side effect that bothers you or that does not go away. These are not all the possible side effects of Doxycycline Hyclate. For more information, ask your doctor or pharmacist. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


Doxycycline Hyclate Delayed-Release Tablets, for oral administration, contain specially coated pellets of doxycycline hyclate, a broad-spectrum antibacterial synthetically derived from oxytetracycline, in a delayed-release formulation for oral administration.

The structural formula for doxycycline hyclate is:

Doxycycline Hyclate Delayed-Release Structural Formula Illustration

with a molecular formula of C22H24N2O8, HCl, ½ C2H6O, ½ H2O and a molecular weight of 512.9. The chemical designation for doxycycline hyclate is [4S(4aR,5S,5aR,6R,12aS)] -4-(dimethylamino)-1,4,4a,5,5a,6,11,12a-octahydro-3,5,10,12,12a-pentahydroxy-6methyl-1,11-deoxonaphthacene-2-carboxamide monohydrochloride, compound with ethyl alcohol (2:1), monohydrate. Doxycycline hyclate is a yellow crystalline powder soluble in water and in solutions of alkali hydroxides and carbonates. Doxycycline has a high degree of lipid solubility and a low affinity for calcium binding. It is highly stable in normal human serum. Doxycycline will not degrade into an epianhydro form. Inactive ingredients in the tablet formulation are: lactose monohydrate; microcrystalline cellulose; sodium lauryl sulfate; sodium chloride; talc; anhydrous lactose; corn starch; crospovidone; magnesium stearate; cellulosic polymer coating.