CVD
Ariel Clark, PharmD
Treatment plans for complex conditions can be—you guessed it—very complex. Chronic pain and CVD are two common disease states that require medication treatment, but despite the high incidence rates of both conditions, there is limited guidance for treating these conditions together.
In a study published in the February 2024 issue of Pharmacotherapy, Leppien and colleagues reviewed recommendations for treating chronic pain in patients who also have CVD while being mindful of potential drug interactions and safety considerations.
In 2018, CDC reported that more than 27% of Americans had two or more chronic conditions, many of which were treated by different independently practicing health care providers. Without a universal EHR system, pharmacists are often the last line of defense to protect patients from adverse events and harmful drug–drug interactions.
Drugs that may be used with additional monitoring
Gabapentinoids and opioids can both be used in patients who have chronic pain and CVD. With these drugs, clinicians should monitor patients for fluid status changes, new onset deep vein thrombosis or other clot formation, and any increased incidence of orthostatic hypotension or syncope.
Providers should be vigilant in watching for CNS depression when using antihypertensives, opioids, muscle relaxants, and gabapentinoids—particularly in older adults who are at an increased risk for falls.
Some antidepressants and anticonvulsants are used to treat neuropathic pain or migraines. The researchers specifically mentioned the use of low-dose TCAs and SNRIs as potential options, with a preference given for SNRIs as the first line treatment.
Anticonvulsants such as carbamezapine, while effective for treating certain types of pain, should be used with caution in these patients due to their high drug interaction potential.
Clonidine and dronabinol are also commonly used in pain management for patients with both chronic pain and CVD. Clinicians can consider using clonidine as an adjunct therapy for patients with both conditions. However, researchers urge caution when considering dronabinol due to its effect on the coagulation pathway.
What and how to monitor?
Drug adverse effects can synergistically worsen when two or more drugs cause the same adverse effect. The study authors suggested pharmacists pay special attention to these additive interactions, including possible somnolence, prolonged QTc intervals, and CNS depression, when monitoring patients with both conditions.
Baseline labs that should be collected vary depending on which drug classes are being considered. These can include baseline heart rate and BP, ECG with QTc interval, electrolytes, INR, glucose levels, A1C, and cholesterol levels. Clinicians should also continually review drug lists for medication changes that could worsen adverse effect profiles.
Drug–drug interactions to note
Many of the drugs used to treat chronic pain and CVD are metabolized in the liver. Liver metabolism causes a number of interactions related to CYP450 enzymes.
Clinicians should be mindful of prescribing medications that share metabolic pathways. Many of the medications used to treat CVD and chronic pain are metabolized by CYP3A4, CYP2C9, CYP2D6, and CYP1A2. Induction and inhibition of these liver enzymes can significantly impact drug bioavailability and the risk of many adverse effects.
Complex conditions will continue to be a balancing act for providers and pharmacists alike when deciding which drug class to use in treatment plans.
The study authors advocated a holistic approach when deciding on a regimen. Pharmacists can review full drug lists, severity and type of pain, and adverse event risks. Working collaboratively with providers from other practice sites is imperative to ensuring patients are not put at unnecessary risk for potentially harmful drug interactions and adverse effects.
Leppien and colleagues suggested continued research into chronic pain management for patients with CVD and the development of standardized guidance supported by clinical trial data. ■