Bactrim Reg Strength (400-80mg) Tab

Sulfamethoxazole inhibits bacterial dihydrofolate synthesis by competing with para-aminobenzoic acid (PABA). Trimethoprim inhibits bacterial dihydrofolate reductase, blocking the reduction of dihydrofolate to tetrahydrofolate. This sequential blockade of two enzymes in the folic acid pathway results in a synergistic antibacterial effect, leading to inhibition of bacterial growth and replication.

Urgent Side Effects: Seek Medical Help Right Away

Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor or seek medical attention immediately:

Allergic Reaction: Rash, hives, itching, red, swollen, blistered, or peeling skin with or without fever, wheezing, tightness in the chest or throat, trouble breathing, swallowing, or talking, unusual hoarseness, or swelling of the mouth, face, lips, tongue, or throat.
High Potassium Levels: Abnormal heartbeat, confusion, weakness, lightheadedness, dizziness, numbness or tingling, or shortness of breath.
Low Blood Sugar: Dizziness, headache, sleepiness, weakness, shaking, rapid heartbeat, confusion, hunger, or sweating.
Kidney Problems: Inability to urinate, changes in urine output, blood in the urine, or significant weight gain.
Low Sodium Levels: Headache, difficulty focusing, memory problems, confusion, weakness, seizures, or balance changes.
Lung or Breathing Problems: Shortness of breath, trouble breathing, cough, or fever.
Pancreas Problems (Pancreatitis): Severe stomach pain, severe back pain, or severe nausea and vomiting.
Other Serious Side Effects:
+ Muscle or joint pain
+ Purple patches on the skin or mouth
+ Hallucinations (seeing or hearing things that are not there)
+ Depression or mood changes
+ Abnormal burning, numbness, or tingling sensations
+ Ringing in the ears
+ Swollen glands
+ Chest pain
+ Pale skin
+ Severe dizziness or fainting

Antibiotic-Related Side Effects:

Diarrhea is a common side effect of antibiotics. However, a rare but severe form called C. diff-associated diarrhea (CDAD) may occur, which can lead to life-threatening bowel problems. If you experience stomach pain, cramps, or loose, watery, or bloody stools, contact your doctor immediately.
Before treating diarrhea, consult your doctor.

Rare but Serious Side Effects:

Sulfa Drug Reactions: Rarely, severe and potentially life-threatening effects have occurred with sulfa drugs, including liver problems, blood disorders, and severe skin reactions (Stevens-Johnson syndrome/toxic epidermal necrolysis). If you experience any of the following symptoms, seek medical attention immediately:
+ Rash
+ Red, swollen, blistered, or peeling skin
+ Red or irritated eyes
+ Sores in the mouth, throat, nose, or eyes
+ Fever, chills, or sore throat
+ New or worsening cough
+ Extreme fatigue or weakness
+ Bruising or bleeding
+ Signs of liver problems, such as dark urine, fatigue, decreased appetite, nausea, light-colored stools, vomiting, or yellow skin and eyes
Aseptic Meningitis: This medication may increase the risk of a severe brain problem called aseptic meningitis. If you experience any of the following symptoms, contact your doctor immediately:
+ Headache
+ Fever
+ Chills
+ Severe nausea or vomiting
+ Stiff neck
+ Rash
+ Sensitivity to light
+ Sleepiness
+ Confusion
Hemophagocytic Lymphohistiocytosis (HLH): A rare but potentially life-threatening immune system problem called HLH has occurred with this medication. If you experience any of the following symptoms, seek medical attention immediately:
+ Fever
+ Swollen glands
+ Rash
+ Seizures
+ Confusion or decreased alertness
+ Balance changes
+ New or worsening difficulty walking

Common Side Effects:

Diarrhea
Stomach pain
Nausea
Vomiting
Decreased appetite

If any of these side effects or other symptoms bother you or do not go away, contact your doctor or seek medical attention.

Reporting Side Effects:

You can report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.

Before Taking This Medication: Important Information to Share with Your Doctor

It is essential to inform your doctor about the following conditions and situations to ensure safe treatment with this medication:

Any known allergies to this drug, its components, or other substances, including foods and medications. Describe the allergic reaction and its symptoms.
A history of anemia caused by a lack of folic acid.
Presence of kidney disease or liver disease.
Certain health conditions, including:
+ Asthma
+ Porphyria
+ Thyroid disease
+ Folate deficiency
+ Malabsorption
+ Poor nutrition
Long-term alcohol consumption or current use of antiseizure medications.
Previous experience with low platelet counts while taking trimethoprim or sulfa (sulfonamide) drugs.
Concurrent use of the following medications:
+ Amantadine
+ Cyclosporine
+ Dofetilide
+ Indomethacin
+ Leucovorin
+ Methotrexate
+ Pyrimethamine
Recent or current use of the following drugs:
+ Benazepril
+ Captopril
+ Enalapril
+ Fosinopril
+ Lisinopril
+ Moexipril
+ Perindopril
+ Quinapril
+ Ramipril
+ Trandolapril
Use of diuretics (water pills).
For children: If your child is under 2 months of age, do not administer this medication, as it is not recommended for infants younger than 2 months.

This list is not exhaustive, and it is crucial to discuss all your medications (prescription, over-the-counter, natural products, and vitamins) and health conditions with your doctor and pharmacist to ensure safe use of this medication. Never start, stop, or adjust the dosage of any medication without consulting your doctor.

It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication. Your doctor will likely recommend regular blood tests and other laboratory evaluations to monitor your condition. Be aware that this drug may interfere with certain lab tests, so it is crucial to notify all your healthcare providers and laboratory personnel that you are taking this medication.

Do not take this medication for longer than prescribed, as this may increase the risk of a second infection. If you have a deficiency of the enzyme glucose-6-phosphate dehydrogenase (G6PD), you may be more susceptible to anemia. Individuals of African, South Asian, Middle Eastern, and Mediterranean descent are more likely to have low G6PD levels.

If you have diabetes (high blood sugar), it is vital to closely monitor your blood sugar levels while taking this medication. Before consuming alcohol, consult with your doctor to discuss any potential risks. This medication may increase your sensitivity to the sun, making you more prone to sunburn. Take necessary precautions when exposed to sunlight, and inform your doctor if you experience excessive sunburning while taking this medication.

In rare cases, this medication can cause a severe and potentially life-threatening reaction, characterized by symptoms such as fever, rash, swollen glands, and problems affecting various organs, including the liver, kidney, blood, heart, muscles and joints, or lungs. If you have any concerns or questions, discuss them with your doctor.

If you are 65 years or older, use this medication with caution, as you may be more susceptible to side effects. Women who are pregnant or become pregnant while taking this medication should contact their doctor immediately, as it may harm the unborn baby. If you are breastfeeding, consult with your doctor to discuss any potential risks to your baby.

• Dofetilide (increased dofetilide concentrations, risk of Torsades de Pointes)

• Warfarin (potentiates anticoagulant effect, increased INR/bleeding risk)
• Methotrexate (increases free methotrexate concentrations, increased toxicity)
• Phenytoin (inhibits phenytoin metabolism, increased phenytoin levels and toxicity)
• Cyclosporine (decreased cyclosporine levels, increased risk of nephrotoxicity)
• Potassium-sparing diuretics (e.g., spironolactone, amiloride), ACE inhibitors, ARBs (increased risk of hyperkalemia)
• Digoxin (increased digoxin levels)
• Sulfonylureas (e.g., glipizide, glyburide) (potentiates hypoglycemic effect)

• Thiazide diuretics (increased risk of thrombocytopenia with purpura in elderly)
• Amantadine (increased amantadine and/or trimethoprim levels, risk of toxicity)
• Procainamide (increased procainamide levels)
• Rifampin (decreased trimethoprim levels)
• Pyrimethamine (increased risk of megaloblastic anemia)

• Tricyclic antidepressants (decreased antidepressant efficacy)
• Oral contraceptives (potential for decreased efficacy)

• Skin rash (including severe blistering, peeling, or red/purple skin rash)
• Fever, sore throat, mouth sores (signs of blood dyscrasias)
• Unusual bleeding or bruising
• Yellowing of skin or eyes (jaundice), dark urine, light-colored stools (signs of liver problems)
• Severe diarrhea (may indicate C. difficile infection)
• Muscle weakness, fatigue, irregular heartbeat (signs of hyperkalemia)
• Signs of superinfection (e.g., new or worsening fever, persistent cough, oral thrush, vaginal yeast infection)

Contraindicated in the third trimester due to the risk of kernicterus in the newborn. Use in the first trimester is generally avoided due to theoretical concerns of folate antagonism, though the risk of birth defects is considered low with standard doses. Benefits must outweigh risks in other trimesters.

Both sulfamethoxazole and trimethoprim are excreted into breast milk. Use with caution. Avoid in infants with G6PD deficiency, hyperbilirubinemia, or those who are ill, premature, or less than 2 months of age due to the risk of kernicterus and hemolytic anemia.

Contraindicated in infants less than 2 months of age due to the risk of kernicterus. Use with caution in children due to potential for adverse effects, especially in those with underlying conditions.

Increased risk of severe adverse reactions, including severe skin reactions, bone marrow suppression, hyperkalemia, and renal impairment. Close monitoring of renal function, electrolytes, and CBC is essential. Lower doses or extended intervals may be necessary.

• Always ensure adequate hydration to prevent crystalluria and kidney stone formation.
• Counsel patients on photosensitivity and the importance of sun protection.
• Be vigilant for signs of severe hypersensitivity reactions (rash, fever, sore throat) and advise immediate discontinuation if they occur.
• Monitor potassium levels, especially in elderly patients, those with renal impairment, or those on concomitant medications that increase potassium (e.g., ACEIs, ARBs, potassium-sparing diuretics).
• Consider folate supplementation in patients on long-term therapy or those at risk for folate deficiency (e.g., pregnant women, malnourished, elderly).
• Not effective against viral infections; avoid inappropriate prescribing to prevent antibiotic resistance.

• Fluoroquinolones (e.g., ciprofloxacin, levofloxacin) for UTIs, respiratory infections
• Beta-lactam antibiotics (e.g., amoxicillin, cephalexin) for UTIs, respiratory infections
• Tetracyclines (e.g., doxycycline) for certain skin infections, respiratory infections
• Macrolides (e.g., azithromycin) for respiratory infections
• Other agents for PCP (e.g., pentamidine, atovaquone, clindamycin + primaquine)

If your symptoms or health issues persist or worsen, it's essential to contact your doctor for further guidance. To ensure your safety, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so be sure to check with your pharmacist for more information. If you have any questions or concerns about your medication, don't hesitate to reach out to your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek medical attention. When seeking help, be prepared to provide details about the medication, including the amount taken and the time it happened, to facilitate prompt and effective treatment.