CO-TRIMOXAZOLE

It is a combination of Sulfonamides exhibiting maximum synergism (Trimethoprim 80 mg with Sulfamethoxazole 400 mg). Additional organisms covered by the combination are salmonella typhi, Serratia, Klebsiella, Yersinia enterocolitica, Pneumocystis carinii and many Sulfonamide resistant strains of staph aureus, strep. pyogenes, shigella, enter pathogenic E.coli, H. influenzae and gonococci. Co-trimoxazole is a combination antibiotic containing sulfamethoxazole and trimethoprim. It belongs to the class of sulfonamides and is used to treat various bacterial infections.

Indications

Urinary tract, Respiratory tract Infections. Typhoid, bacterial diarrhoeas and dysentery, Septicaemias, Gonorrhoea, Chancroid, whooping cough and for prophylaxis and therapeutic treatment of severe infection of Pneumocystis carinii in neutropenic patients. -Bacterial Infections: Co-trimoxazole is effective against a wide range of bacterial infections, including urinary tract infections, respiratory tract infections, and skin infections. -Pneumocystis jirovecii Pneumonia (PCP): It is also used for the prevention and treatment of PCP, a serious lung infection that can occur in individuals with weakened immune systems, such as those with HIV/AIDS.

Dosage

-Dosage may vary depending on the specific infection and patient characteristics. It is crucial to follow the prescribed dosage and duration. -Trimethoprim Sulfamethoxazole. 80 mg+400 mg tab: 2BD for 2 days then 1BD, 160 mg+800 mg tab: Double strength (D.S) 1BD, 20 mg + 100 mg paediatric tab 1BD, 40 mg + 200 mg per 5 ml susp: infant 2.5 ml, children 1-5 yrs 5 ml, 6-12 yrs 10 ml (all B.D), 160 mg + 800 mg per 3 ml for i.m.inj 12 hrly, 80 mg + 400 mg per 5 ml for i.v inj 10-15 ml B.D

Contra-Indications

-Co-trimoxazole is contraindicated in patients with: Hypersensitivity to sulfonamides or trimethoprim. Severe liver or kidney disease. Blood disorders, such as aplastic anemia and megaloblastic anemia. -Hypersensitivity to either sulphonamides or trimethoprim. Not to be used in premature or infants of few weeks. Marked liver parenchymal damage, blood dyscrasias and severe renal insufficiency, unless blood levels can be closely monitored.

Special Precautions

-Patients with folate deficiency may require supplementation. -Caution is advised in individuals with impaired renal function. -Avoid prolonged exposure to sunlight, as co-trimoxazole may increase sensitivity. -Patients with history of allergies, urinary obstruction, blood dyscrasias, hepatic and renal impairment, bronchial asthma. Not to be used in pregnancy because of the possible teratogenic effects of inducing folate deficiency. Paediatrics: Reduced dose necessary. Not recommended in infants under 6 weeks. Pregnancy: Contraindicated. Lactation: Use with caution. Elderly: Possibility of side effects.

Side Effects

Allergic reactions include rash, fever, hepatitis, agranulocytosis, purpura, aplastic anaemia, peripheral neuritis. Skin reactions including erythema multiforme bullosa & toxic epidermal necrolysis. Other side effects include Crystalluria causing renal colic, heaematuria, oliguria, less serious effects include malaise, headache, nausea or vomiting, diarrhoea, mental depression & rarely cyanosis. -Common side effects may include nausea, vomiting, diarrhea, rash, and allergic reactions. Serious side effects such as Stevens-Johnson syndrome or blood disorders are rare but require immediate medical attention.

Drug Interactions

-Warfarin: Increased risk of bleeding. -Methotrexate: Enhanced potential for toxicity. -Phenytoin: Increased phenytoin levels. -Digoxin: Increased risk of digoxin toxicity. -Co-administration with pyrimethamine causes megaloblastic anaemia.