Does amoxicillin and doxycycline treat the same infections?

DOXYCYCLINE

Doxycycline is a broad-spectrum antibiotic synthetically derived from oxytetracycline. Monodox 100 mg, 75 mg, and 50 mg capsules contain doxycycline monohydrate equivalent to 100 mg, 75 mg, or 50 mg of doxycycline for oral administration. The chemical designation of the light-yellow crystalline powder is alpha-6-deoxy-5-oxytetracycline.

Structural formula:

C22H24N2O8 • H2O M.W.=462.45

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.

Inert ingredients: colloidal silicon dioxide; hard Gelatin capsule which contains black iron oxide, red iron oxide, titanium dioxide, and yellow iron oxide for the 100 mg and 75 mg strengths, titanium dioxide and yellow iron oxide for the 50 mg strength; magnesium stearate; microcrystalline cellulose; and sodium starch glycolate.

AMOXICILLIN

Formulations of AMOXIL contain amoxicillin, a semisynthetic antibiotic, an analog of ampicillin, with a broad spectrum of bactericidal activity against many gram-positive and gram-negative microorganisms. Chemically, it is (2S,5R,6R)-6-[(R)-(-)-2-amino-2-(p­hydroxyphenyl)acetamido]-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid trihydrate. It may be represented structurally as:

The amoxicillin molecular formula is C16H19N3O5S• 3H2O, and the molecular weight is 419.45.

Capsules, tablets, and powder for oral suspension of AMOXIL (amoxicillin) are intended for oral administration.

Capsules: Each capsule of AMOXIL (amoxicillin) , with royal blue opaque cap and pink opaque body, contains 500 mg amoxicillin as the trihydrate. The cap and body of the 500-mg capsule are imprinted with AMOXIL (amoxicillin) and 500. Inactive ingredients: D&C Red No. 28, FD&C Blue No. 1, FD&C Red No. 40, gelatin, magnesium stearate, and titanium dioxide.

Tablets: Each tablet contains 500 mg or 875 mg amoxicillin as the trihydrate. Each film-coated, capsule-shaped, pink tablet is debossed with AMOXIL (amoxicillin) centered over 500 or 875, respectively. The 875-mg tablet is scored on the reverse side. Inactive ingredients: Colloidal silicon dioxide, crospovidone, FD&C Red No. 30 aluminum lake, hypromellose, magnesium stearate, microcrystalline cellulose, polyethylene glycol, sodium starch glycolate, and titanium dioxide.

Chewable Tablets: Each cherry-banana-peppermint-flavored tablet contains 200 mg or 400 mg amoxicillin as the trihydrate.

Each 200-mg chewable tablet contains 0.0005 mEq (0.0107 mg) of sodium; the 400-mg chewable tablet contains 0.0009 mEq (0.0215 mg) of sodium. The 200-mg and 400-mg pale pink round tablets are imprinted with the product name AMOXIL (amoxicillin) and 200 or 400 along the edge of 1 side. Inactive ingredients: Aspartame®, crospovidone NF, FD&C Red No. 40 aluminum lake, flavorings, magnesium stearate, and mannitol.

*See PRECAUTIONS.

Powder for Oral Suspension: Each 5 mL of reconstituted suspension contains 200 mg, 250 mg, or 400 mg amoxicillin as the trihydrate. Each 5 mL of the 250-mg reconstituted suspension contains 0.15 mEq (3.36 mg) of sodium. Each 5 mL of the 200-mg reconstituted suspension contains 0.15 mEq (3.39 mg) of sodium; each 5 mL of the 400-mg reconstituted suspension contains 0.19 mEq (4.33 mg) of sodium.

Pediatric Drops for Oral Suspension: Each mL of reconstituted suspension contains 50 mg amoxicillin as the trihydrate and 0.03 mEq (0.69 mg) of sodium.

Amoxicillin trihydrate for oral suspension 200 mg/5 mL, 250 mg/5 mL (or 50 mg/mL), and 400 mg/5 mL are bubble-gum-flavored pink suspensions. Inactive ingredients: FD&C Red No. 3, flavorings, silica gel, sodium benzoate, sodium citrate, sucrose, and xanthan gum.