Interactions and contraindications
Interactions and contraindications ( 5 Questions)
A nurse is teaching a client who has a urinary tract infection (UTI) about trimethoprim/sulfamethoxazole. The client asks why he needs to take two antibiotics together.
What should the nurse say?
The combination of trimethoprim and sulfamethoxazole has a synergistic effect that inhibits bacterial growth more effectively than either drug alone. This means that the two drugs work together to produce a greater effect than the sum of their individual effects.
Choice B is wrong because the combination of trimethoprim and sulfamethoxazole does not have an additive effect that reduces the dosage and frequency of administration of each drug.
The dosage and frequency of administration are determined by the severity of the infection, the renal function of the client, and the susceptibility of the bacteria.
Choice C is wrong because the combination of trimethoprim and sulfamethoxazole does not have an antagonistic effect that prevents the development of resistance to either drug.
Antagonistic effect means that one drug reduces or cancels out the effect of another drug.
The combination of trimethoprim and sulfamethoxazole may still cause resistance in some bacteria.
Choice D is wrong because the combination of trimethoprim and sulfamethoxazole does not have a selective effect that targets only the bacteria causing the UTI and spares the normal flora.
Selective effect means that a drug affects only certain types of cells or organisms.
The combination of trimethoprim and sulfamethoxazole is a broad-spectrum antibiotic that can affect both gram-positive and gram-negative bacteria, including some normal flora.
No explanation
The combination of trimethoprim and sulfamethoxazole has a synergistic effect that inhibits bacterial growth more effectively than either drug alone. This means that the two drugs work together to produce a greater effect than the sum of their individual effects.
Choice B is wrong because the combination of trimethoprim and sulfamethoxazole does not have an additive effect that reduces the dosage and frequency of administration of each drug.
The dosage and frequency of administration are determined by the severity of the infection, the renal function of the client, and the susceptibility of the bacteria.
Choice C is wrong because the combination of trimethoprim and sulfamethoxazole does not have an antagonistic effect that prevents the development of resistance to either drug.
Antagonistic effect means that one drug reduces or cancels out the effect of another drug.
The combination of trimethoprim and sulfamethoxazole may still cause resistance in some bacteria.
Choice D is wrong because the combination of trimethoprim and sulfamethoxazole does not have a selective effect that targets only the bacteria causing the UTI and spares the normal flora.
Selective effect means that a drug affects only certain types of cells or organisms.
The combination of trimethoprim and sulfamethoxazole is a broad-spectrum antibiotic that can affect both gram-positive and gram-negative bacteria, including some normal flora.