Question

A post-operative client has an order for Demerol (meperidine) \(75 \mathrm{mg}\) and Phenergan (promethazine) 25mg IM every 3-4 hours as needed for pain. The combination of the two medications produces a/an: A. Agonist effect B. Synergistic effect C. Antagonist effect D. Excitatory effect

Short answer

Answer: A synergistic effect is produced when Demerol and Phenergan are combined for a post-operative client.

Step-by-step solution

Understand the medications

Demerol, also known as meperidine, is an opioid analgesic used for the treatment of pain. Phenergan, also known as promethazine, is an antihistamine used for allergies and also works as a sedative. These two medications are often given in combination to manage post-operative pain.

Define the Effects

A. Agonist effect: An agonist is a substance that binds to and activates a specific receptor, causing a physiological response. An agonist effect occurs when a drug enhances or stimulates a particular response. B. Synergistic effect: A synergistic effect occurs when the combined effect of two drugs is greater than the sum of their individual effects. In other words, they work together to produce a stronger result. C. Antagonist effect: An antagonist is a substance that blocks or inhibits the action of a specific receptor. An antagonist effect occurs when one drug inhibits or counteracts the effect of another drug. D. Excitatory effect: An excitatory effect occurs when a drug or substance increases the likelihood of an action potential or neural firing.

Determine the Combined Effect

In this case, the combination of Demerol and Phenergan results in a synergistic effect (Option B). This is because Demerol provides pain relief, while Phenergan enhances the sedative effect and helps reduce nausea. When taken together, the combined effect is more effective for pain relief than if either were taken separately.

Key concepts

Post-Operative Pain Management

Effective management of post-operative pain is crucial for promoting patient comfort, facilitating recovery, and preventing complications after surgery. Pain control methods can range from non-pharmacological approaches to various types of medications. Among the pharmacological options, opioid analgesics are commonly prescribed due to their potent pain-relieving properties.

• Opioid analgesics like Demerol (meperidine) work by mimicking the action of naturally occurring pain-reducing chemicals in the body, effectively decreasing the perception of pain.
• Additionally, medications such as Phenergan (promethazine), an antihistamine with sedative properties, can be administered to alleviate other post-operative discomforts like nausea and to potentiate the effects of opioids.
• The goal is to ensure the patient experiences minimal pain while also minimizing opioid-related side effects, thus enhancing the recovery process.

In terms of administration, dosing schedules are carefully considered to maintain a balance between pain relief and side effects. The frequent assessment of pain levels is necessary to tailor the medication regimen to the individual patient's needs, aiming for the most effective and safe pain management strategy.

Synergistic Effect of Medications

The synergistic effect of medications occurs when drugs interact in a way that their combined therapeutic effects are greater than the sum of their separate effects. This principle is often applied in clinical settings to enhance patient outcomes while potentially lowering individual drug doses to reduce the risk of side effects.

Understanding Synergy in Pharmacology

When two drugs with complementary mechanisms of action are used together, as in the case of Demerol and Phenergan, the pain relief can be significantly enhanced, as well as the quality of the patient's recovery experience. For example:

• Demerol provides analgesic effects, directly reducing pain sensation.
• Phenergan contributes sedative effects, which can not only help a patient rest but also augment the analgesic effect of Demerol.
• This combination can also help in decreasing anxiety, inducing relaxation, and providing a sense of well-being.

Such combinations should always be used judiciously and under medical supervision, as the interaction of different pharmacological agents can also lead to increased risks of adverse effects.

Opioid Analgesic and Antihistamine Combination

The combination of an opioid analgesic like Demerol with an antihistamine such as Phenergan is a common strategy to enhance analgesic efficacy and reduce adverse effects in post-operative pain management.

Benefits of Combining Opioids with Antihistamines

The rationale behind combining these types of medications includes:

• Augmentation of pain relief (analgesic effect) of the opioid.
• Decrease in the dose of opioid needed, potentially reducing opioid-related side effects like respiratory depression and addiction.
• Added antiemetic effect from the antihistamine, which helps to alleviate nausea and vomiting that are commonly associated with opioid use and post-operative conditions.
• Enhanced sedative effects contributing to better rest post-surgery.

However, it is essential to monitor patients closely for potential side effects such as increased sedation and respiratory depression. Healthcare providers should evaluate the patient's pain and response to treatment regularly, adjusting the dosage accordingly and ensuring safety is upheld throughout the post-operative care process.