Doryx Dosage

Important Dosage and Administration Instructions

• DORYX is not substitutable on a mg per mg basis with other oral doxycyclines. To avoid prescribing errors, do not substitute DORYX for other oral doxycyclines on a mg per mg basis because of differing bioavailability.
• Do not chew or crush tablets [see Dosage and Administration (2.4)] .
• The recommended dosage, frequency of administration and weight-based dosage recommendations of DORYX differ from that of the other tetracyclines [see Dosage and Administration (2.2, 2.3, 2.4)] . Exceeding the recommended dosage may result in an increased incidence of adverse reactions.
• Administer DORYX with an adequate amount of fluid to wash down the drug and reduce the risk of esophageal irritation and ulceration [see Adverse Reactions (6.1)] .
• If gastric irritation occurs, DORYX may be given with food or milk [see Clinical Pharmacology (12.3)] .

Switching from DORYX to DORYX MPC

When switching from DORYX to DORYX MPC:

• A 60 mg dose of DORYX MPC will replace a 50 mg dose of DORYX
• A 120 mg dose of DORYX MPC will replace a 100 mg dose of DORYX

Dosage in Adult Patients

• The usual dosage of DORYX is 200 mg on the first day of treatment (administered 100 mg every 12 hours), followed by a maintenance dose of 100 mg daily.
• The maintenance dose may be administered as a single dose or as 50 mg every 12 hours.
• In the management of more severe infections (particularly chronic infections of the urinary tract), 100 mg every 12 hours is recommended.
• For certain selected specific indications, the recommended duration or dosage and duration of DORYX MPC in adult patients are as follows:
  1. Streptococcal infections, therapy should be continued for 10 days.
  2. Uncomplicated urethral, endocervical, or rectal infection caused by C. trachomatis: 100 mg, by mouth, twice-a-day for 7 days.
  3. Uncomplicated gonococcal infections in adults (except anorectal infections in men): 100 mg, by mouth, twice-a-day for 7 days. As an alternate single visit dose, administer 300 mg followed in one hour by a second 300 mg dose.
  4. Nongonococcal urethritis (NGU) caused by U. urealyticum: 100 mg, by mouth, twice-a-day for 7 days.
  5. Syphilis – early: Patients who are allergic to penicillin should be treated with doxycycline 120 mg, by mouth, twice-a-day for 2 weeks.
  6. Syphilis of more than one year's duration: Patients who are allergic to penicillin should be treated with doxycycline 100 mg, by mouth, twice-a-day for 4 weeks.
  7. Acute epididymo-orchitis caused by N. gonorrhoeae: 100 mg, by mouth, twice-a-day for at least 10 days.
  8. Acute epididymo-orchitis caused by C. trachomatis: 100 mg, by mouth, twice-a-day for at least 10 days

Dosage in Pediatric Patients

• For all pediatric patients weighing less than 45 kg with severe or life threatening infections (e.g., anthrax, Rocky Mountain spotted fever), the recommended dosage of doxycycline is 2.2 mg per kg of body weight administered every 12 hours. Pediatric patients weighing 45 kg or more should receive the adult dose [see Warnings and Precautions (5.1)] .
• For pediatric patients with less severe disease (greater than 8 years of age and weighing less than 45 kg), the recommended dosage schedule of doxycycline is 4.4 mg per kg of body weight divided into two doses on the first day of treatment, followed by a maintenance dose of 2.2 mg per kg of body weight (given as a single daily dose or divided into twice daily doses). For pediatric patients weighing over 45 kg, the usual adult dose should be used.

Dosage for Prophylaxis of Malaria

For adults, the recommended dose of DORYX is 100 mg daily. For pediatric patients 8 years of age and older, the recommended dose is 2 mg/kg administered once daily up to the adult dose. Pediatric patients weighing 45 kg or more should receive the adult dose.

Prophylaxis should begin 1 or 2 days before travel to the malarious area. Prophylaxis should be continued daily during travel in the malarious area and for 4 weeks after the traveler leaves the malarious area.

Dosage for Inhalational Anthrax (Post-Exposure)

For adults the recommended dosage is 100 mg of DORYX, by mouth, twice-a-day for 60 days.

For pediatric patients weighing less than 45 kg, the recommended dosage of DORYX is 2.2 mg/kg of body weight, by mouth, twice-a-day for 60 days. Pediatric patients weighing 45 kg or more should receive the adult dose.

Sprinkling the Tablet Over Applesauce

DORYX may also be administered by carefully breaking up the tablet and sprinkling the tablet contents (delayed-release pellets) on a spoonful of applesauce. The delayed-release pellets must not be crushed or damaged when breaking up the tablet. Any loss of pellets in the transfer would prevent using the dose. The applesauce/DORYX mixture should be swallowed immediately without chewing and may be followed by a glass of water if desired. The applesauce should not be hot, and it should be soft enough to be swallowed without chewing. In the event that a prepared dose of applesauce/DORYX mixture cannot be taken immediately, the mixture should be discarded and not stored for later use.