Doryx MPC (doxycycline hyclate delayed-release tablets) for oral use, contain doxycycline hyclate, a tetracycline class drug synthetically derived from oxytetracycline, in a delayed-release formulation consisting of pellets with a modified polymer enteric coat that has increased acid resistance. The structural formula for doxycycline hyclate is: with a molecular formula of C 22 H 24 N 2 O 8 , HCl, ½ C 2 H 6 O, ½ H 2 O and a molecular weight of 512.9. The chemical name 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-6-methyl-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. Each tablet contains doxycycline 60 mg (equivalent to doxycycline hyclate 69.4 mg) or doxycycline 120 mg (equivalent to doxycycline hyclate 138.8 mg). 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. Each DORYX MPC 60 mg Tablet contains 3.6 mg (0.157 mEq) of sodium. Each DORYX MPC 120 mg Tablet contains 7.2 mg (0.313 mEq) of sodium. Chemical Structure

DORYX MPC is a tetracycline class drug indicated for: Rickettsial Infections Sexually Transmitted Infections Respiratory Tract Infections( 1.3 ) Specific Bacterial Infections Ophthalmic Infections Anthrax, Including Inhalational Anthrax (Post-Exposure) Alternative Treatment for Selected Infections when Penicillin is Contraindicated Adjunctive Therapy in Acute Intestinal Amebiasis and Severe Acne Prophylaxis of Malaria Usage To reduce the development of drug-resistant bacteria and maintain the effectiveness of doxycycline hyclate and other antibacterial drugs, DORYX MPC Tablets should be used only to treat or prevent infections that are proven or strongly suspected to be caused by bacteria

Rickettsial Infections DORYX MPC is indicated for treatment of Rocky Mountain spotted fever, typhus fever and the typhus group, Q fever, rickettsialpox, and tick fevers caused by Rickettsiae

Sexually Transmitted Infections DORYX MPC is indicated for treatment of the following sexually transmitted infections: Uncomplicated urethral, endocervical or rectal infections in adults caused by Chlamydia trachomatis. Nongonococcal urethritis caused by Ureaplasma urealyticum . Lymphogranuloma venereum caused by Chlamydia trachomatis . Granuloma inguinale caused by Klebsiella granulomatis . Uncomplicated gonorrhea caused by Neisseria gonorrhoeae . Chancroid caused by Haemophilus ducreyi

Respiratory Tract Infections DORYX MPC is indicated for treatment of the following respiratory tract infections: Respiratory tract infections caused by Mycoplasma pneumoniae . Psittacosis (ornithosis) caused by Chlamydophila psittaci . Because many strains of the following groups of microorganisms have been shown to be resistant to doxycycline, culture and susceptibility testing are recommended. Doxycycline is indicated for treatment of infections caused by the following microorganisms, when bacteriological testing indicates appropriate susceptibility to the drug: Respiratory tract infections caused by Haemophilus influenzae . Respiratory tract infections caused by Klebsiella species. Upper respiratory infections caused by Streptococcus pneumoniae

Specific Bacterial Infections DORYX MPC is indicated for treatment of the following specific bacterial infections: Relapsing fever due to Borrelia recurrentis . Plague due to Yersinia pestis . Tularemia due to Francisella tularensis . Cholera caused by Vibrio cholerae . Campylobacter fetus infections caused by Campylobacter fetus . Brucellosis due to Brucella species (in conjunction with streptomycin). Bartonellosis due to Bartonella bacilliformis . Because many strains of the following groups of microorganisms have been shown to be resistant to doxycycline, culture and susceptibility testing are recommended. DORYX MPC is indicated for treatment of infections caused by the following gram-negative microorganisms, when bacteriological testing indicates appropriate susceptibility to the drug: Escherichia coli Enterobacter aerogenes Shigella species Acinetobacter species Urinary tract infections caused by Klebsiella species

Ophthalmic Infections DORYX MPC is indicated for treatment of the following ophthalmic infections: Trachoma caused by Chlamydia trachomatis , although the infectious agent is not always eliminated as judged by immunofluorescence. Inclusion conjunctivitis caused by Chlamydia trachomatis

Anthrax Including Inhalational Anthrax (Post-Exposure) DORYX MPC is indicated for treatment of Anthrax due to Bacillus anthracis , including inhalational anthrax (post-exposure): to reduce the incidence or progression of disease following exposure to aerosolized Bacillus anthracis

Alternative Treatment for Selected Infections when Penicillin is Contraindicated DORYX MPC is indicated as an alternative treatment for the following selected infections when penicillin is contraindicated: Syphilis caused by Treponema pallidum . Yaws caused by Treponema pallidum subspecies pertenue . Listeriosis due to Listeria monocytogenes . Vincent's infection caused by Fusobacterium fusiforme. Actinomycosis caused by Actinomyces israelii . Infections caused by Clostridium species

Adjunctive Therapy for Acute Intestinal Amebiasis and Severe Acne In acute intestinal amebiasis, DORYX MPC may be a useful adjunct to amebicides. In severe acne, DORYX MPC may be useful adjunctive therapy

Prophylaxis of Malaria DORYX MPC is indicated for the prophylaxis of malaria due to Plasmodium falciparum in short-term travelers (less than 4 months) to areas with chloroquine and/or pyrimethamine-sulfadoxine resistant strains [ see Dosage and Administration and Patient Counseling Information (17) ]

Usage To reduce the development of drug-resistant bacteria and maintain the effectiveness of DORYX MPC and other antibacterial drugs, DORYX MPC should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.

DORYX MPC (doxycycline hyclate delayed-release tablets), 60 mg are white, oval tablets containing yellow pellets and debossed with "D6" on one face and plain on the other. Each tablet contains doxycycline 60 mg (equivalent to doxycycline hyclate 69.4 mg). DORYX MPC Delayed-Release Tablets 60 mg

Important Dosage and Administration Instructions: DORYX MPC is not substitutable on a mg per mg basis with other oral doxycyclines. Do not chew or crush tablets. 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. In the management of more severe infections (particularly chronic infections of the urinary tract), 120 mg every 12 hours is recommended. 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. 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. See Full Prescribing Information for additional indication specific dosage information and important administration instructions for DORYX MPC. ( 2.2 , 2.5 , 2.6 ) 2.1 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 ]. If gastric irritation occurs, DORYX MPC may be given with food or milk

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 2.3 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: Streptococcal infections, therapy should be continued for 10 days. Uncomplicated urethral, endocervical, or rectal infection caused by C. trachomatis : 120 mg, by mouth, twice-a-day for 7 days. 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. Nongonococcal urethritis (NGU) caused by C. trachomatis and U. urealyticum : 120 mg, by mouth, twice-a-day for 7 days. Syphilis – early: Patients who are allergic to penicillin should be treated with doxycycline 120 mg, by mouth, twice-a-day for 2 weeks. 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. Acute epididymo-orchitis caused by N. gonorrhoeae : 120 mg, by mouth, twice-a-day for at least 10 days. Acute epididymo-orchitis caused by C. trachomatis : 120 mg, by mouth, twice-a-day for at least 10 days 2.4 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 . 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.

The use of drugs of the tetracycline-class during tooth development (last half of pregnancy, infancy and childhood to the age of 8 years) may cause permanent discoloration of the teeth (yellow-gray-brown). Clostridioides difficile -Associated Diarrhea. Evaluate patients if diarrhea occurs. Photosensitivity manifested by an exaggerated sunburn reaction has been observed in some individuals taking tetracyclines. Limit sun exposure. Overgrowth of non-susceptible organisms, including fungi, may occur. If such infections occur, discontinue use and institute appropriate therapy. 5.1 Tooth Development The use of drugs of the tetracycline-class during tooth development (last half of pregnancy, infancy and childhood to the age of 8 years) may cause permanent discoloration of the teeth (yellow-gray-brown). This adverse reaction is more common during long-term use of the drugs but it has been observed following repeated short-term courses. Enamel hypoplasia has also been reported. Use DORYX MPC in pediatric patients 8 years of age or less only when the potential benefits are expected to outweigh the risks in severe or life-threatening conditions (e.g., anthrax, Rocky Mountain spotted fever), particularly when there are no alternative therapies

Clostridioides difficile Associated Diarrhea Clostridioides difficile associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including DORYX MPC Tablets, and may range in severity from mild diarrhea to fatal colitis. Treatment with antibacterial agents alters the normal flora of the colon leading to overgrowth of C. difficile . C. difficile produces toxins A and B which contribute to the development of CDAD. Hypertoxin producing strains of C. difficile cause increased morbidity and mortality, as these infections can be refractory to antimicrobial therapy and may require colectomy. CDAD must be considered in all patients who present with diarrhea following antibacterial use. Careful medical history is necessary since CDAD has been reported to occur over two months after the administration of antibacterial agents. If CDAD is suspected or confirmed, ongoing antibacterial use not directed against C. difficile may need to be discontinued. Appropriate fluid and electrolyte management, protein supplementation, antibacterial treatment of C . difficile , and surgical evaluation should be instituted as clinically indicated

Photosensitivity Photosensitivity manifested by an exaggerated sunburn reaction has been observed in some individuals taking tetracyclines. Patients apt to be exposed to direct sunlight or ultraviolet light should be advised that this reaction can occur with tetracycline drugs, and treatment should be discontinued at the first evidence of skin erythema

Potential for Microbial Overgrowth DORYX MPC may result in overgrowth of non-susceptible organisms, including fungi. If such infections occur, discontinue use and institute appropriate therapy

Severe Skin Reactions Severe skin reactions, such as exfoliative dermatitis, erythema multiforme, Stevens-Johnson syndrome, toxic epidermal necrolysis, and drug reaction with eosinophilia and systemic symptoms (DRESS) have been reported in patients receiving doxycycline. Fixed drug eruptions have occurred with doxycycline and have been associated with worsening severity upon subsequent administrations, including generalized bullous fixed drug eruption . If severe skin reactions occur, discontinue DORYX MPC immediately and institute appropriate therapy

Intracranial Hypertension Intracranial hypertension (IH, pseudotumor cerebri) has been associated with the use of tetracycline including DORYX MPC. Clinical manifestations of IH include headache, blurred vision, diplopia, and vision loss; papilledema can be found on fundoscopy. Women of childbearing age who are overweight or have a history of IH are at greater risk for developing tetracycline associated IH. Avoid concomitant use of isotretinoin and DORYX MPC because isotretinoin is also known to cause pseudotumor cerebri. Although IH typically resolves after discontinuation of treatment, the possibility for permanent visual loss exists. If visual disturbance occurs during treatment, prompt ophthalmologic evaluation is warranted. Since intracranial pressure can remain elevated for weeks after drug cessation patients should be monitored until they stabilize

Skeletal Development All tetracyclines form a stable calcium complex in any bone-forming tissue. A decrease in fibula growth rate has been observed in prematures given oral tetracycline in doses of 25 mg/kg every six hours. This reaction was shown to be reversible when the drug was discontinued. [ See Use in Specific Populations ]

Antianabolic Action The antianabolic action of the tetracyclines may cause an increase in BUN. Studies to date indicate that this does not occur with the use of doxycycline in patients with impaired renal function

Malaria Doxycycline offers substantial but not complete suppression of the asexual blood stages of Plasmodium strains. Doxycycline does not suppress P. falciparum's sexual blood stage gametocytes. Subjects completing this prophylactic regimen may still transmit the infection to mosquitoes outside endemic areas

Development of Drug-Resistant Bacteria Prescribing DORYX MPC in the absence of a proven or strongly suspected bacterial infection or a prophylactic indication is unlikely to provide benefit to the patient and increases the risk of the development of drug-resistant bacteria

Laboratory Monitoring for Long-Term Therapy In long-term therapy, periodic laboratory evaluation of organ systems, including hematopoietic, renal, and hepatic studies should be performed.

Patients who are on anticoagulant therapy may require downward adjustment of their anticoagulant dosage Avoid co-administration of tetracyclines with penicillin Absorption of tetracyclines, including DORYX MPC is impaired by antacids containing aluminum, calcium, or magnesium, bismuth subsalicylate and iron-containing preparations Concurrent use of tetracyclines, including DORYX MPC may render oral contraceptives less effective Barbiturates, carbamazepine, and phenytoin decrease the half-life of doxycycline 7.1 Anticoagulant Drugs Because tetracyclines have been shown to depress plasma prothrombin activity, patients who are on anticoagulant therapy may require downward adjustment of their anticoagulant dosage

Penicillin Since bacteriostatic drugs may interfere with the bactericidal action of penicillin, it is advisable to avoid giving tetracyclines, including DORYX MPC in conjunction with penicillin

Antacids and Iron Preparations Absorption of tetracyclines including DORYX MPC is impaired by antacids containing aluminum, calcium, or magnesium, bismuth subsalicylate, and iron-containing preparations

Oral Contraceptives Concurrent use of tetracyclines, including DORYX MPC may render oral contraceptives less effective

Barbiturates and anti-epileptics Barbiturates, carbamazepine, and phenytoin decrease the half-life of doxycycline

Drug/Laboratory Test Interactions False elevations of urinary catecholamines may occur due to interference with the fluorescence test.