A nurse is caring for a client who is taking warfarin and reports taking several new herbal supplements. The nurse should identify that which of the following supplements is contraindicated for concurrent use with warfarin?

Answer: C

Rationale:

A) Inject air into the vial with regular insulin in it:

Injecting air into the vial of regular insulin is part of the correct procedure but not the initial step. This action is typically performed after the NPH insulin vial has been handled, as part of the process to prevent contamination and maintain the correct insulin types.

B) Draw up the NPH insulin dose:

Drawing up the NPH insulin dose should follow the initial steps of air injection. It is important to manage the insulin types in the correct sequence to ensure that the regular insulin remains uncontaminated by the NPH insulin.

C) Inject air into the vial with NPH insulin in it:

Injecting air into the NPH insulin vial first helps to equalize the pressure and avoid contamination when drawing up the insulin. This step is crucial to ensure that the NPH insulin is not inadvertently mixed with the regular insulin, maintaining the integrity of each type.

D) Draw up the regular insulin dose:

Drawing up the regular insulin dose should occur after air has been injected into both vials. This ensures that the NPH insulin is not drawn into the regular insulin syringe, which could affect the medication's efficacy.

A. “Oxycodone blocks the sodium channel suspending nerve conduction”: Oxycodone does not primarily act by blocking sodium channels. Sodium channel blockers are typically local anesthetics or antiarrhythmic medications.

B. “Oxycodone causes central nervous system depression”: Oxycodone is an opioid analgesic that works by binding to opioid receptors in the brain and spinal cord, reducing the perception of pain. However, it can also depress the central nervous system, slowing breathing. This can lead to a decreased respiratory rate, which is why the client’s respiratory rate is 8/min.

C. “Oxycodone inhibits prostaglandin synthesis”: Oxycodone does not primarily act by inhibiting prostaglandin synthesis. Nonsteroidal anti-inflammatory drugs (NSAIDs) typically work by inhibiting prostaglandin synthesis.

D. “Oxycodone promotes vasodilation of cranial arteries”: Oxycodone does not primarily act by promoting vasodilation of cranial arteries. Medications that dilate cranial arteries are typically used to treat migraines and cluster headaches.