SULFAPYRIDINE (Systemic)

Some commonly used brand names are:

In Canada?

• Dagenan

Generic name product may be available in the U.S. and Canada.

Category

• Dermatitis herpetiformis suppressant

Description

Sulfapyridine (sul-fa-PEER-i-deen)is a sulfa medicine. It is used to help control dermatitis herpetiformis (Duhring'sdisease), a skin problem. It may also be used for other problems as determinedby your doctor. However, this medicine will not work for any kind of infectionas other sulfa medicines do.

This medicine may cause some serious side effects. Before using this medicine, be sure to talk to your doctor about these problems,as well as the good this medicine will do.

Sulfapyridine is available only with your doctor's prescription, in thefollowing dosage form:

Oral
• Tablets (U.S. and Canada)

Before Using This Medicine

In deciding to use a medicine,the risks of taking the medicine must be weighed against the good it willdo. This is a decision you and your doctor will make. For sulfapyridine, thefollowing should be considered:

Allergies?Tell your doctor if you have ever had any unusual orallergic reaction to sulfa medicines, furosemide (e.g., Lasix) or thiazidediuretics (water pills), oral antidiabetics (diabetes medicine you take bymouth), glaucoma medicine you take by mouth (acetazolamide [e.g., Diamox],dichlorphenamide [e.g., Daranide], methazolamide [e.g., Neptazane]), or pyrimethamine(e.g., Daraprim). Also tell your health care professional if you are allergicto any other substances, such as foods, preservatives, or dyes.

Pregnancy?Studies have not been done in humans. Studies inrats and mice have shown that some sulfa medicines, given by mouth in highdoses, cause birth defects, including cleft palate and bone problems. In addition,sulfa medicines may cause liver problems in newborn infants. Therefore, useis not recommended during pregnancy.

Breast-feeding?Sulfapyridine passes into the breast milk. Thismedicine may cause liver problems in nursing babies. In addition, it may causeblood problems in nursing babies with glucose-6-phosphate dehydrogenase (G6PD)deficiency (lack of G6PD enzyme). Therefore, use is not recommended in nursingwomen.

Children?Use of this medicine is not recommended since dermatitisherpetiformis usually does not occur in children.

Older adults?Many medicines have not been studied specificallyin older people. Therefore, it may not be known whether they work exactlythe same way they do in younger adults or if they cause different side effectsor problems in older people. There is no specific information comparing theuse of sulfapyridine in the elderly with use in other age groups.

Other medicines?Although certain medicines should not be usedtogether at all, in other cases two different medicines may be used togethereven if an interaction might occur. In these cases, your doctor may want tochange the dose, or other precautions may be necessary. When you are takingsulfapyridine, it is especially important that your health care professionalknow if you are taking any of the following:

• Acetaminophen (e.g., Tylenol) (with long-term, high-dose use) or
• Amiodarone (e.g., Cordarone) or
• Anabolic steroids (nandrolone [e.g., Anabolin], oxandrolone [e.g.,Anavar], oxymetholone [e.g., Anadrol], stanozolol [e.g., Winstrol]) or
• Androgens (male hormones) or
• Antithyroid agents (medicine for overactive thyroid) or
• Carbamazepine (e.g., Tegretol) or
• Carmustine (e.g., BiCNU) or
• Chloroquine (e.g., Aralen) or
• Dantrolene (e.g., Dantrium) or
• Daunorubicin (e.g., Cerubidine) or
• Disulfiram (e.g., Antabuse) or
• Divalproex (e.g., Depakote) or
• Estrogens (female hormones) or
• Etretinate (e.g., Tegison) or
• Gold salts (medicine for arthritis) or
• Hydroxychloroquine (e.g., Plaquenil) or
• Mercaptopurine (e.g., Purinethol) or
• Naltrexone (e.g., Trexan) (with long-term, high-dose use) or
• Oral contraceptives (birth control pills) containing estrogen or
• Other anti-infectives by mouth or by injection (medicine for infection)or
• Phenothiazines (acetophenazine [e.g., Tindal], chlorpromazine [e.g.,Thorazine], fluphenazine [e.g., Prolixin], mesoridazine [e.g., Serentil],perphenazine [e.g., Trilafon], prochlorperazine [e.g., Compazine], promazine[e.g., Sparine], promethazine [e.g., Phenergan], thioridazine [e.g., Mellaril],trifluoperazine [e.g., Stelazine], triflupromazine [e.g., Vesprin], trimeprazine[e.g., Temaril]) or
• Plicamycin (e.g., Mithracin) or
• Valproic acid (e.g., Depakene)?Use of sulfapyridine with thesemedicines may increase the chance of side effects affecting the liver

• Acetohydroxamic acid (e.g., Lithostat) or
• Dapsone or
• Furazolidone (e.g., Furoxone) or
• Nitrofurantoin (e.g., Furadantin) or
• Primaquine or
• Procainamide (e.g., Pronestyl) or
• Quinidine (e.g., Quinidex) or
• Quinine (e.g., Quinamm) or
• Sulfoxone (e.g., Diasone) or
• Vitamin K (e.g., AquaMEPHYTON, Synkayvite)?Use of sulfapyridinewith these medicines may increase the chance of side effects affecting theblood

• Anticoagulants (blood thinners) or
• Ethotoin (e.g., Peganone) or
• Mephenytoin (e.g., Mesantoin)?Use of sulfapyridine with thesemedicines may increase the chance of side effects of these medicines

• Antidiabetics, oral (diabetes medicine you take by mouth)?Useof oral antidiabetics with sulfapyridine may increase the chance of side effectsaffecting the blood and/or the side effects or oral antidiabetics

• Methotrexate (e.g., Mexate)?Use of methotrexate with sulfapyridinemay increase the chance of side effects affecting the liver and/or the sideeffects of methotrexate

• Methyldopa (e.g., Aldomet)?Use of methyldopa with sulfapyridinemay increase the chance of side effects affecting the liver and/or the blood

• Phenytoin (e.g., Dilantin)?Use of phenytoin with sulfapyridinemay increase the chance of side effects affecting the liver and/or the sideeffects of phenytoin

Other medical problems?The presence of other medicalproblems may affect the use of sulfapyridine. Make sure you tell your doctorif you have any other medical problems, especially:

• Blood problems or
• Glucose-6-phosphate dehydrogenase deficiency (lack of G6PD enzyme)?Patientswith these problems may have an increase in side effects affecting the blood

• Kidney disease or
• Liver disease?Patients with kidney disease or liver diseasemay have an increased chance of side effects

• Porphyria?Use of sulfapyridine may cause an attack of porphyria

Proper Use of This Medicine

Each dose of sulfapyridine should be taken with a full glass (8 ounces) ofwater. Several additional glasses of water should be taken every day,unless otherwise directed by your doctor. Drinking extra water will help toprevent some unwanted effects (e.g., kidney stones) of the sulfa medicine.

For patients taking sulfapyridine for dermatitis herpetiformis:

• Your doctor may want you to follow a strict, gluten-free diet.
• You may have to use this medicine regularly for 6 months to a yearbefore you can reduce the dose of sulfapyridine or stop it altogether. Ifyou have any questions about this, check with your doctor.

Dosing?The dose of sulfapyridine will be differentfor different patients. Follow your doctor's orders orthe directions on the label. The following information includes onlythe average doses of sulfapyridine. Your dose may be different if you havekidney disease. If your dose is different, do not changeit unless your doctor tells you to do so.

• For dermatitis herpetiformis:
  • Adults and adolescents: 250 milligrams to 1 gram four times a dayuntil improvement occurs. After improvement has occurred, the dose shouldthen be reduced by 250 to 500 milligrams every three days until there areno symptoms; that dose should be taken once daily.
  • Children: Use is not recommended, because children usually do notget this condition.

Missed dose?For patients taking sulfapyridine for dermatitis herpetiformis: You may skip a missed dose if this doesnot make your symptoms return or get worse. If your symptoms do return orget worse, take the missed dose as soon as possible. Then go back to yourregular dosing schedule.

Storage?To store this medicine:

• Keep out of the reach of children.
• Store away from heat and direct light.
• Do not store in the bathroom, near the kitchen sink, or in otherdamp places. Heat or moisture may cause the medicine to break down.
• Do not keep outdated medicine or medicine no longer needed. Be surethat any discarded medicine is out of the reach of children.

Precautions While Using This Medicine

It is very important that your doctor check your progress atregular visits. This medicine may cause blood problems, especiallyif it is taken for a long time.

If your symptoms do not improve within a few days, or if they become worse,check with your doctor.

Sulfapyridine may cause blood problems. These problems may result in agreater chance of certain infections, slow healing, and bleeding of the gums.Therefore, you should be careful when using regular toothbrushes, dental floss,and toothpicks. Dental work should be delayed until your blood counts havereturned to normal. Check with your medical doctor or dentist if you haveany questions about proper oral hygiene (mouth care) during treatment.

Sulfapyridine may cause your skin to be more sensitive to sunlight thanit is normally. Exposure to sunlight, even for brief periods of time, maycause a skin rash, itching, redness or other discoloration of the skin, ora severe sunburn. When you begin taking this medicine:

• Stay out of direct sunlight, especially between the hours of 10:00A.M. and 3:00 P.M., if possible.
• Wear protective clothing, including a hat. Also, wear sunglasses.
• Apply a sun block product that has a skin protection factor (SPF)of at least 15. Some patients may require a product with a higher SPF number,especially if they have a fair complexion. If you have any questions aboutthis, check with your health care professional.
• Apply a sun block lipstick that has an SPF of at least 15 to protectyour lips.
• Do not use a sunlamp or tanning bed or booth.

You may still be more sensitive to sunlight or sunlamps for many monthsafter stopping this medicine. If you have a severe reactionfrom the sun, check with your doctor.

Tell the doctor in charge that you are taking this medicine before youhave any medical tests. The results of the bentiromide (e.g., Chymex) testfor pancreas function are affected by this medicine.

Side Effects of This Medicine

Along with its needed effects, a medicine may cause some unwanted effects.Although not all of these side effects may occur, if they do occur they mayneed medical attention.

Check with your doctorimmediately if any of the following side effects occur:

More common

Fever; headache (continuing); itching; skin rash

Less common

Aching of joints and muscles; difficultyin swallowing; pale skin; redness, blistering, peeling, or loosening of skin; sore throat; unusual bleeding or bruising; unusual tiredness or weakness; yelloweyes or skin

Rare

Blood in urine; lower back pain; pain or burning while urinating; swellingof front part of neck

Also, check with your doctor as soon as possible if the followingside effect occurs:

More common

Increased sensitivity of skin to sunlight

Other sideeffects may occur that usually do not need medical attention. These side effectsmay go away during treatment as your body adjusts to the medicine. However,check with your doctor if any of the following side effects continue or arebothersome:

More common

Diarrhea; loss of appetite; nausea or vomiting

Other side effects not listed above may also occur in some patients. Ifyou notice any other effects, check with your doctor.

Additional Information

Once a medicine has been approvedfor marketing for a certain use, experience may show that it is also usefulfor other medical problems. Although these uses are not included in productlabeling, sulfapyridine is used in certain patients with the following medicalconditions:

• Pemphigoid
• Pyoderma gangrenosum
• Subcorneal pustular dermatitis

Other than the above information, there is no additional information relatingto proper use, precautions, or side effects for these uses.