Doryx Dosage

Important Dosage and Administration Instructions

• DORYX MPC is not substitutable on a mg per mg basis with other oral doxycyclines. To avoid prescribing errors, do not substitute DORYX MPC for other oral doxycyclines on a mg per mg basis because of differing bioavailability.
• Do not chew or crush tablets.
• The recommended dosage, frequency of administration and weight-based dosage recommendations of DORYX MPC 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 MPC with an adequate amount of fluid to wash down the drug and reduce the risk of esophageal irritation and ulceration [see Adverse Reactions (6)].
• If gastric irritation occurs, DORYX MPC 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 MPC is 240 mg on the first day of treatment (administered 120 mg every 12 hours) followed by a maintenance dose of 120 mg daily. The maintenance dose may be administered as a single dose or as 60 mg every 12 hours.
• In the management of more severe infections (particularly chronic infections of the urinary tract), 120 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: 120 mg, by mouth, twice-a-day for 7 days.
  3. Uncomplicated gonococcal infections in adults (except anorectal infections in men): 120 mg, by mouth, twice-a-day for 7 days. As an alternate single visit dose, administer 360 mg followed in one hour by a second 360 mg dose.
  4. Nongonococcal urethritis (NGU) caused by C. trachomatis and U. urealyticum: 120 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 120 mg, by mouth, twice-a-day for 4 weeks.
  7. Acute epididymo-orchitis caused by N. gonorrhoeae: 120 mg, by mouth, twice-a-day for at least 10 days.
  8. Acute epididymo-orchitis caused by C. trachomatis: 120 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 DORYX MPC is 2.6 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 DORYX MPC is 5.3 mg per kg of body weight divided into two doses on the first day of treatment, followed by a maintenance dose of 2.6 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 MPC is 120 mg daily.

For pediatric patients 8 years of age and older, the recommended dosage of DORYX MPC is 2.4 mg per kg of body weight administered once daily. 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 120 mg, of DORYX MPC, by mouth, twice-a-day for 60 days.

For pediatric patients weighing less than 45 kg, the recommended dosage of DORYX MPC is 2.6 mg per kg of body weight, by mouth, twice-a-day for 60 days. Pediatric patients weighing 45 kg or more should receive the adult dose.