Doxycycline, USP  is  a  broad - spectrum  antibacterial  synthetically  derived  from  oxytetracycline.  Doxycycline  monohydrate  capsules  USP,  100  mg  and  75  mg  contain   doxycycline  monohydrate  equivalent  to  100  mg  and  75  mg  of  doxycycline  for  oral  administration.  The  chemical  designation  of  the  light  yellow  to  pale  yellow  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:  microcrystalline  cellulose; sodium  starch  glycolate;  povidone;  colloidal  silicon  dioxide;  magnesium  stearate;  and  a  hard  gelatin  capsule  which  contains  iron  oxide  black,  iron  oxide  red,  iron  oxide  yellow,  titanium dioxide,  gelatin  and  sodium  lauryl  sulphate.  The  capsule  shells  of  75  mg  are  printed  with  edible  black  ink  containing  shellac,  propylene  glycol,  iron  oxide  black  and  potassium  hydroxide.  The  cap  of  100  mg  capsule  shells  is  printed  with  edible  white  ink  containing  shellac,  propylene  glycol,  potassium  hydroxide  and  titanium  dioxide.   The  body  of  100  mg  capsule  shells  is  printed  with  edible  and  brown  ink  containing  shellac,  propylene  glycol,  potassium  hydroxide,  iron  oxide  brown  and  iron  oxide  black.

Tetracyclines are readily absorbed and are bound to plasma proteins in varying degrees. They are concentrated by the liver in the bile and excreted in the urine and feces at high concentrations in a biologically active form. Doxycycline is virtually completely absorbed after oral administration.

Following a 200 mg dose of doxycycline monohydrate, 24 normal adult volunteers averaged the following serum concentration values:

Average Observed Values

Maximum Concentration                                3.61 μg/mL (± 0.9 sd)

Time of Maximum Concentration                   2.6 hr (± 1.1 sd)

Elimination Rate Constant                              0.049 per hr (± 0.03 sd)

Half-Life                                                         16.33 hr (± 4.53 sd)

Excretion of doxycycline by the kidney is about 40%/72 hours in individuals with normal function (creatinine clearance about 75 mL/min). This percentage excretion may fall as low as 1 to 5%/72 hours in individuals with severe renal insufficiency (creatinine clearance below 10 mL/min). Studies have shown no significant difference in serum half-life of doxycycline (range 18 to 22 hours) in individuals with normal and severely impaired renal function. Hemodialysis does not alter serum half-life.



Population pharmacokinetic analysis of sparse concentration-time data of doxycycline following standard of care intravenous and oral dosing in 44 pediatric patients (2 to 18 years of age) showed that allometrically-scaled clearance (CL) of doxycycline in pediatric patients ≥2 to ≤8 years of age (median [range] 3.58 [2.27 to 10.82] L/h/70 kg, N =11) did not differ significantly from pediatric patients >8 to 18 years of age (3.27 [1.11 to 8.12] L/h/70 kg, N=33). For pediatric patients weighing ≤45 kg, body weight normalized doxycycline CL in those ≥2 to ≤8 years of age (median [range] 0.071 [0.041 to 0.202] L/kg/h, N=10) did not differ significantly from those >8 to 18 years of age (0.081 [0.035 to 0.126] L/kg/h, N=8). In pediatric patients weighing >45 kg, no clinically significant differences in body weight normalized doxycycline CL were observed between those ≥2 to ≤8 years (0.05 L/kg/h, N=1) and those >8 to 18 years of age (0.044 [0.014 to 0.121] L/kg/h, N=25). No clinically significant difference in CL between oral and IV dosing was observed in the small cohort of pediatric patients who received the oral (N=19) or IV (N=21) formulation alone.



Microbiology: 

Mechanism of Action 

Doxycycline inhibits bacterial protein synthesis by binding to the 30S ribosomal subunit. Doxycycline has bacteriostatic activity against a broad range of Gram-positive and Gram-negative bacteria. 

Resistance

Cross resistance with other tetracyclines is common. 



Antimicrobial Activity

Doxycycline has been shown to be active against most isolates of the following microorganisms, both in vitro and in clinical infections (see INDICATIONS AND USAGE).

Gram-Negative Bacteria 

Acinetobacter species 

Bartonella bacilliformis 

Brucella species 

Campylobacter fetus 

Enterobacter aerogenes 

Escherichia coli 

Francisella tularensis 

Haemophilus ducreyi 

Haemophilus influenzae

Klebsiella granulomatis 

Klebsiella species 

Neisseria gonorrhoeae 

Shigella species 

Vibrio cholerae 

Yersinia pestis

Gram-Positive Bacteria 

Bacillus anthracis

Listeria monocytogenes 

Streptococcus pneumoniae 

Anaerobic Bacteria 

Clostridium species 

Fusobacterium fusiforme 

Propionibacterium acnes



Other Bacteria 

Nocardiae and other Actinomyces species 

Borrelia recurrentis 

Chlamydophila psittaci 

Chlamydia trachomatis 

Mycoplasma pneumoniae 

Rickettsiae 

Treponema pallidum 

Treponema pallidum subspecies pertenue 

Ureaplasma urealyticum 

Parasites 

Balantidium coli 

Entamoeba species



Susceptibility Testing 

For specific information regarding susceptibility test interpretive criteria and associated test methods and quality control standards recognized by FDA for this drug, please see: https://www.fda.gov/STIC.

To reduce the development of drug-resistant bacteria and maintain effectiveness of doxycycline capsules, USP and other antibacterial drugs, doxycycline capsules, USP 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.

Doxycycline is indicated for the treatment of the following infections:

Rocky Mountain spotted fever, typhus fever and the typhus group, Q fever, rickettsialpox, and tick fevers caused by Rickettsiae. 

  Respiratory tract infections caused by Mycoplasma pneumoniae.

  Lymphogranuloma venereum caused by Chlamydia trachomatis.

  Psittacosis (ornithosis) caused by Chlamydophila psittaci.

  Trachoma caused by Chlamydia trachomatis, although the infectious agent is not always eliminated as judged by immunofluorescence.

  Inclusion conjunctivitis caused by Chlamydia trachomatis.

  Uncomplicated urethral, endocervical or rectal infections in adults caused by Chlamydia trachomatis.

  Nongonococcal urethritis caused by Ureaplasma urealyticum.

  Relapsing fever due to Borrelia recurrentis.

 Doxycycline is also indicated for the treatment of infections caused by the following gram-negative microorganisms:

  Chancroid caused by Haemophilus ducreyi.

  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.

  Granuloma inguinale caused by Klebsiella granulomatis.

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 gram-negative microorganisms, when bacteriologic testing indicates appropriate susceptibility to the drug:

            Escherichia coli

            Enterobacter aerogenes

            Shigella species

            Acinetobacter species

            Respiratory tract infections caused by Haemophilus influenzae.

            Respiratory tract and urinary tract infections caused by Klebsiella species.

Doxycycline is indicated for treatment of infections caused by the following gram-positive microorganisms when bacteriologic testing indicates appropriate susceptibility to the drug:

            Upper respiratory infections caused by Streptococcus pneumoniae.

            Anthrax due to Bacillus anthracis, including inhalational anthrax (post-exposure): to reduce the incidence or progression of disease following exposure to aerosolized Bacillus anthracis.

When penicillin is contraindicated, doxycycline is an alternative drug in the treatment of the following infections:

            Uncomplicated gonorrhea caused by Neisseria gonorrhoeae.

            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.

In acute intestinal amebiasis, doxycycline may be a useful adjunct to amebicides.

In severe acne, doxycycline may be useful adjunctive therapy.

This drug is contraindicated in persons who have shown hypersensitivity to any of the tetracyclines.

The use of drugs of the tetracycline class, including doxycycline, 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 of doxycycline 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. 

Clostridium difficile associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including doxycycline capsules, 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 antibiotic 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 antibiotic use not directed against C. difficile may need to be discontinued. Appropriate fluid and electrolyte management, protein supplementation, antibiotic treatment of C. difficile, and surgical evaluation should be instituted as clinically indicated.

Intracranial hypertension (IH, pseudotumor cerebri) has been associated with the use of tetracyclines including doxycycline capsules. 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. Concomitant use of isotretinoin and doxycycline capsules should be avoided 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. 

All tetracyclines form a stable calcium complex in any bone-forming tissue. A decrease in the 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.

Results of animal studies indicate that tetracyclines cross the placenta, are found in fetal tissues, and can have toxic effects on the developing fetus (often related to retardation of skeletal development). Evidence of embryo toxicity has been noted in animals treated early in pregnancy. If any tetracycline is used during pregnancy or if the patient becomes pregnant while taking these drugs, the patient should be apprised of the potential hazard to the fetus.

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.

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.

Due to oral doxycycline’s virtually complete absorption, side effects to the lower bowel, particularly diarrhea, have been infrequent. The following adverse reactions have been observed in patients receiving tetracyclines.

Gastrointestinal: Anorexia, nausea, vomiting, diarrhea, glossitis, dysphagia, enterocolitis, and inflammatory lesions (with monilial overgrowth) in the anogenital region, and pancreatitis. Hepatotoxicity has been reported. These reactions have been caused by both the oral and parenteral administration of tetracyclines. Rare instances of esophagitis and esophageal ulcerations have been reported in patients receiving capsule and tablet forms of drugs in the tetracycline class. Most of these patients took medications immediately before going to bed. (See DOSAGE AND ADMINISTRATION.)

Skin: Maculopapular and erythematous rashes, Stevens-Johnson syndrome, toxic epidermal necrolysis, and erythema multiforme have been reported. Exfoliative dermatitis has been reported but is uncommon. Photosensitivity is discussed above. (See WARNINGS.)

Renal Toxicity: Rise in BUN has been reported and is apparently dose related. (See WARNINGS.)

Hypersensitivity Reactions: Urticaria, angioneurotic edema, anaphylaxis, anaphylactoid purpura, serum sickness, pericarditis, and exacerbation of systemic lupus erythematosus.

Blood: Hemolytic anemia, thrombocytopenia, neutropenia, and eosinophilia have been reported with tetracyclines.

Other: Intracranial hypertension (IH, pseudotumor cerebri) has been associated with the use of tetracyclines. (See PRECAUTIONS-General.)

When given over prolonged periods, tetracyclines have been reported to produce brown-black microscopic discoloration of the thyroid gland. No abnormalities of thyroid function are known to occur.

In case of overdosage, discontinue medication, treat symptomatically and institute supportive measures. Dialysis does not alter serum half-life, and it would not be of benefit in treating cases of overdosage.

THE USUAL DOSAGE AND FREQUENCY OF ADMINISTRATION OF DOXYCYCLINE DIFFERS FROM THAT OF THE OTHER TETRACYCLINES. EXCEEDING THE RECOMMENDED DOSAGE MAY RESULT IN AN INCREASED INCIDENCE OF SIDE EFFECTS.

Adults: The usual dose of oral doxycycline is 200 mg on the first day of treatment (administered 100 mg every 12 hours or 50 mg every 6 hours) followed by a maintenance dose of 100 mg/day. 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.

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 is 2.2 mg/kg of body weight administered every 12 hours. Children weighing 45 kg or more should receive the adult dose (see WARNINGS and PRECAUTIONS).

For pediatric patients with less severe disease (greater than 8 years of age and weighing less than 45 kg), the recommended dosage schedule 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.

The therapeutic antibacterial serum activity will usually persist for 24 hours following recommended dosage.

When used in streptococcal infections, therapy should be continued for 10 days.

Administration of adequate amounts of fluid along with capsule and tablet forms of drugs in the tetracycline class is recommended to wash down the drugs and reduce the risk of esophageal irritation and ulceration. (See ADVERSE REACTIONS)

If gastric irritation occurs, it is recommended that doxycycline be given with food or milk. The absorption of doxycycline is not markedly influenced by simultaneous ingestion of food or milk.

Studies to date have indicated that administration of doxycycline at the usual recommended doses does not lead to excessive accumulation of doxycycline in patients with renal impairment. 

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 stat followed in one hour by a second 300 mg dose.

Acute epididymo-orchitis caused by N. gonorrhoeae: 100 mg, by mouth, twice a day for at least 10 days.

Primary and secondary syphilis: 300 mg a day in divided doses for at least 10 days.

Uncomplicated urethral, endocervical, or rectal infection in adults caused by Chlamydia trachomatis: 100 mg, by mouth, twice a day for at least 7 days.

Nongonococcal urethritis caused by C. trachomatis and U. urealyticum: 100 mg, by mouth, twice a day for at least 7 days.

Acute epididymo-orchitis caused by C. trachomatis: 100 mg, by mouth, twice a day for at least 10 days.

Inhalational anthrax (post-exposure): ADULTS: 100 mg of doxycycline, by mouth, twice a day for 60 days. CHILDREN: weighing less than 45 kg; 2.2 mg/kg of body weight, by mouth, twice a day for 60 days. Children weighing 45 kg or more should receive the adult dose.

Doxycycline capsules USP, 75   mg   are opaque brown cap/opaque white body hard gelatin capsules size “2” having imprinting “A” on cap with black ink and “241” on body with black ink filled with yellow to brown granular powder. Each   capsule   contains   doxycycline   monohydrate    equivalent   to   75   mg   doxycycline.

NDC   62332-249-30    bottle of 30 capsules

NDC   62332-249-31    bottle of 100 capsules

Doxycycline  capsules USP, 100   mg   are opaque brown cap/opaque yellow body hard gelatin capsules size “1” having imprinting “A” on cap with white ink and “242” on body with brown ink filled with yellow to brown granular powder. Each   capsule   contains   doxycycline   monohydrate   equivalent  to   100   mg  doxycycline.

NDC  62332-250-30    bottle  of  30  capsules

NDC 62332-250-50    bottles  of  50  capsules

NDC  62332-250-60    bottle of  60  capsules

NDC  62332-250-61    bottle of  250 capsules

Store at 25°C (77°F); excursions permitted to 15° to 30°C (59° to 86°F) [see USP Controlled Room Temperature].

Dispense  in a  tight  light- resistant   container   as  defined   in   the  USP/NF. 

Hyperpigmentation of the thyroid has been produced by members of the tetracycline class in the following species: in rats by oxytetracycline, doxycycline, tetracycline PO4, and methacycline; in minipigs by doxycycline, minocycline, tetracycline PO4, and methacycline; in dogs by doxycycline and minocycline; in monkeys by minocycline.

Minocycline, tetracycline PO4, methacycline, doxycycline, tetracycline base, oxytetracycline HCl and tetracycline HCl were goitrogenic in rats fed a low iodine diet. This goitrogenic effect was accompanied by high radioactive iodine uptake. Administration of minocycline also produced a large goiter with high radioiodine uptake in rats fed a relatively high iodine diet.

Treatment of various animal species with this class of drugs has also resulted in the induction of thyroid hyperplasia in the following: in rats and dogs (minocycline), in chickens (chlortetracycline) and in rats and mice (oxytetracycline). Adrenal gland hyperplasia has been observed in goats and rats treated with oxytetracycline.

Call your doctor for medical advice about side effects. You may report side effects to Alembic Pharmaceuticals Limited at 1-866-210-9797 or FDA at 1-800-FDA-1088.

1.      Friedman JM and Polifka JE. Teratogenic Effects of Drugs. A Resource for Clinicians (TERIS). Baltimore, MD: The Johns Hopkins University Press: 2000: 149-195. 

2.      Cziezel AE and Rockenbauer M. Teratogenic study of doxycycline. Obstet Gynecol 1997;89:524-528. 

3.  Horne HW Jr. and Kundsin RB. The role of mycoplasma among 81 consecutive pregnancies: a prospective study. Int J Fertil 1980; 25:315-317. 

4.  Hale T.Medications and Mothers Milk. 9th edition. Amarillo, TX: Pharmasoft Publishing 2000; 225-226. 

Manufactured by:

Alembic Pharmaceuticals Limited

(Formulation Division),

Panelav 389350, Gujarat, India 

Manufactured for:

Alembic Pharmaceuticals, Inc.

Bedminster, NJ 07921, USA 

Revised: 08/2021

NDC 62332-249-30

Doxycycline

Capsules, USP

75 mg

Alembic

Rx only

30 Capsules

NDC 62332-250-30

Doxycycline

Capsules, USP

100 mg

Alembic

Rx only

30 Capsules