Sulfamethoxazole with Trimethoprim (Sulfonamide Antibiotic)

Question 1

What are the brand names of sulfamethoxazole with trimethoprim?

Answer 1

Bactrim & Septra

Question 2

What are the strength tablets available for sulfamethoxazole with trimethoprim?

Answer 2

Regular strength 80mg/400mg

Double Strength 160mg/800mg

Question 3

What strength of sulfamethoxazole with trimethoprim is available as a suspension?

Answer 3

40mg/5mL Trimeth

200mg/5mL Sulfa

Question 4

What strength of sulfamethoxazole with trimethoprim is available as an injection?

Answer 4

80mg/5mL Trimeth

400mg/5mL Sulfa

Question 5

What dose of sulfamethoxazole with trimethoprim is used when treating urinary tract infections due to susceptible strains of E. coli, klebsiella enterobacter, P. mirabilis, P. vulgarisms, and P. morganii, shiegllosis due to susceptible strains of S. flexneri or S. somnei, and acute exacerbation of chronic bronchitis in adults.

Answer 5

160mg trimethoprim/800mg sulfamethoxazole every 12 hours for 10 to 14 days

Question 6

What does of sulfamethoxazole with trimethoprim is used for the treatment of travelers diarrhea in adults?

Answer 6

One double strength tablet every 12 hours for five days

Question 7

What is the mechanism of action for trimethoprim? What is the mechanism of action for sulfamethoxazole?

Answer 7

Trimethoprim: blocks the production of tetrahydrofolic acid by inhibiting the enzyme dihydrofolate reductase.

Sulfamethoxazole: inhibits bacterial synthesis of dihydrofolic acid by competitive antagonism of para aminobenzoic acid

Question 8

What are the drug interactions for sulfamethoxazole with trimethoprim?

Answer 8

• May decrease effects of cyclosporine.
• May increase the serum levels of procainamide and hydantoins.
• May increase the effects of oral anticoagulants and sulfonylureas

Question 9

What are the contraindications for sulfamethoxazole with trimethoprim?

Answer 9

• Contraindicated in infants less than two months of age, during pregnancy, and nursing mothers, and patients allergic to sulfa drugs, and in patients with a megaloblastic anemia due to folate deficiency. Use with caution in patients with impaired renal or hepatic function.
• Pregnancy Category D

Question 10

What are the adverse effects sulfamethoxazole with trimethoprim?

Answer 10

Increase sensitivity to light, Stevens Johnson syndrome, nausea, vomiting, diarrhea, dizziness, anorexia, and rash.

Question 11

What should a RPh tell the patient when counseling them for sulfamethoxazole with trimethoprim?

Answer 11

• Preferably taken on an empty stomach one hour before or two hours after meals with a full glass (240 mLs) of water
• Complete full course therapy unless otherwise directed
• Avoid prolonged exposure to sunlight
• Shake suspension well before using
• If a dose is missed, take it as soon as possible.